li?A.WvVi7, ®1|F i. % ItU ICihrarii Jfortlj QIaralttta S-tatf Qlollrgp NA2521 Arch. lib. 9 NA2i:21 S45 Arch. Lib. 129734 PERMANENT RESERVE i>^i S H AWS CIVIL ARCHITECTURE; BEING A COMPLETE THEORETICAL AND PRACTICAL SYSTEM OF BUILDING, CONTAINING THE FUNDAMENTAL PRINCIPLES OF THE ART, ILLUSTRATED BY EIGHTY-TWO COPPERPLATE ENGRAVINGS. By EDWARD SHAW, Architect. SIXTH EDITION, REVISED AND IMPROVED. TO WHICH AEE ADDED TWENTY COPPERPLATE ENGRAVINGS, ALSO, A TREATISE ON GOTHIC ARCHITECTURE, WITH PLATES, &c BY THOMAS W. SILLOWAY AND GEORGE M. HARDING, AKCHITECTS. BOSTON : PUBLISHED BY JOHN P. JEWETT AND COMPANY CLEVELAND, OHIO : JEWETT, PROCTOR, AND WORTHINGTON. MDCCCLII. Entered according to act of Congress, in tlie year 1859, by LUTHER STEVENS, In the Clerk's Office of the District Court of the District of Massachusetts. ADYERTISEMENT TO THE FIRST EDITION. It is obvious that most writers on CivU Architecture have not entered into those mathematical principles on which this noble art ultimately rests, and from which it derives its very existence. They may rather be said to consider it merely as an art than as a science also, and are more cal- culated to instruct the student in dra-\ving architectiu'al plans than to point out and elucidate those imalterable rules and first principles which, however unperceived, (as Mr. Nicholson justly observes,) must enter into the very essence of every plan that is correct and practicable. The student, in the outset, should commence his inquiry by going back to the most simple elements of mathematical knowledge, there to obtain the real clew to his future studies, and from thence, gradually and scientifically, to proceed to more complex problems and more diversified plans. On this principle is founded the superior skUl of the Grecian and Eoman artists, which has, as yet, been mirivalled. We should not content ourselves by merely drawing from their works, and then superadding the invention of our ovm imagination ; but we should continually recur to the ground on which they trod, and make that the criterion of all our attempts. It is principally to assist the practical mechanic, as well as the student, that this work has been projected ; and, as will appear, much pains have been taken to lay down the fundamental principles of architectiu'e m a clear, distinct, and intelligible manner, and to apply the whole to practice by plain and obvious examples and illustrations. I have endeavored to arrange the contents so as to be useful to the student, as well as to all classes of operative builders. Those workmen, therefore, Avho aspire to any degree of superiority and taste in either of these branches, will be able from hence, by improving their leisure hours, in a short time to understand the principles of theu- respective occupations, and to execute with taste and pleasure what they do now but mechanically. In this work is given whatever the experience of the most judicious professors has sanctioned as the best mode of affecting their professional purposes, with the reasons on which that preference is founded. To this are added examples both of Grecian and Roman antiquities, and remarks on the beauties of each. Particular attention is paid to the theory of shadows, both from dhcct and reflected light, and examples adduced of the relative degrees of light and shade on different sur- faces, variously inclined to the luminary and the eye. Also, a select set of problems are di'awn from Nicholson's writings, entirely new, and all ultimately connected with the subject in hand. lJc9784 4 ADVERTISEMENT. They are disposed in methodical order, and are preceded by the necessary definitions. It is not intended by this part wholly to set aside the study of Euclid and authors who have written on Conic Sections. An attentive perusal of their works will always amply repay the student's trouble. When the vast importance and utility of Geometry are considered, the student will never regret any pains he may take to make himself thoroughly master of every part of it. Particular atten- tion has been paid to ellipses and curves — the problems relating to which will be found par- ticularly useful in describing elliptical and Gothic arches, finding their joints, and describing mouldings of every degree of cru'vature, under various circimistances, with Conic Sections ; also, the Sections of Solids, a thorough acquaintance with them being absolutely necessary for under- standing the theory and disposition of shadows, the explanation of which will be highly gratifying to every scientific reader. In view of the present taste for architectural knowledge, and the inadequacy of means to obtain that science, arising from the costly and voluminous works on the subject, I have been chiefly induced to compile a work of this kind. Being fully convinced of its utility, from very arduous research into its constituent principles, from my early apprenticeship to the present time, — having had more than twenty years' practice in the art of building, — I have brought together the following system in a concise but intelligible manner, Avhich consists principally of extracts from Vitruvius, Stuart, Chambers, Nicholson, and other authors of eminence. If I have made a judicious arrangement of the several subjects, I have accomplished all I anticipated ; and under these considerations, therefore, I submit this work to the public for their approbation and patronage. EDWARD SHAW. ADYEETISEMENT TO THE SIXTH EDITION. Being encouraged by the rapid and extensive sale of the five former editions of this work, and the urgent calls made in consequence of its having been out of print for several years, I have been induced by the advice of my friends to secure the valuable services of Messrs. SUloway and Harding, architects of Boston, gentlemen well versed in the science they profess, to assist in revising the fifth edition, and prepare additional di-awings for a sixth, which has resulted in the exclusion of several of the old plates, and the substitution of twenty new ones of a character in keeping with the improvements of the day, and of great practical use to the carpenter and builder, among which are four plates of Gothic details selected from Pugin, one of the best of the English authors on this subject. The sixth edition, thus improved and enlarged, I now offer for the attention and patronage of an enlightened public. EDWARD SHAW. Januaky 1, 1852. CONTENTS. PAGE PLATE INTRODUCTION. 9 Construction of Houses, 17 Doors and Windows, 18 Mouldings, 22 To draw Volutes, Columns, and Cornices, 22, 23 Construction of Bridges, 27 Wooden Bridges, 32 Iron Bridges, 33 Western Avenue, 34 Warren Bridge, 34 PRACTICAL GEOMETRY. Definition of Lines and Points, 37 1 Circles, 38 2 Problems on Points and Lines 39 2, 3 Trapeziums, 43 4 CONIC SECTIONS. Definitions, 45 5 Ellipses, 46 (i Conjugates, 47 7 To describe Ellipses, 48 8 The Parabola, 49 9 Hyperbola 50 10 To describe a Conic Section, 51 11 Sections of Solids, 52 12 Sections of a Cone, 53 12, 13 Cycloid or Epicycloid, 56 13 Section of Planes, 56 14 Application of the Trihedral, 57 14 Principles of Projection, 59 15 Development of tlie Surfaces of Solids, 59 15 Projections of Prisms, 64 16 SHADOWS. Efiect of Distance, 66 Seat of the Sun's Rays, 67 17 Upright Prisms, 68 18 Polygonal Ring, 69 19 Elevation of a Circular Ring, 70 19 Lines of Light and Shade on a Sphere, 71 20 PAGE PLATE Lines of Light and Shade from the Abacus of a Cylinder, 71 20 Light and Shade on a Prism, 72 21 ESect of do. on Mouldings, 73 22 Base and Capital, 77 23, 24 Of a Cylmdrical Recess, 78 25 A Hemisphere, 78 25 MOULDINGS. Definitions, 79 Roman Mouldings, 80 26 Modem " 82 27 Grecian « 82 28,29 Architraves, 83 30 ORDERS. Tuscan Order of Vitruvius, 84 31 Modern Tuscan Order, 84 32 ROMAN DORIC. Example by Palladio, 85 33 Example from the Diocletian Baths, 86 34 Roman Doric, as approved by Chambers, 85 35 ROMAN CORINTHIAN. Example from the Temple of Jupiter Stator, 87 36 Details of the same, 87 37 Example from the Pantheon, at Rome, 87 38 COMPOSITE ORDER. Example from the Arch of Titus, at Rome, 87 39 Pilasters, 88 Arcades and Arches, 90 40 Pedestals, 90 41 Imposts and Bases, 92 42 Balusters and Balustrades, 93 43 GRECIAN ORDERS. Definitions, 94 Grecian Doric, 95 Temple of Minerva, at Athens, 97 44 8 CONTENTS. PAGE PLATE Details of the same, i^'' 45 Example from the Temple of Theseus, at Atliens,. . . 97 46 Example from the Portico of Philip, King of Macedon, 98 47 Choragic Monument of Thrasyllus, 98 48 GRECIAN IONIC. Example from the River Hyssus 99 49 Details of the same 99 50, 51 « u 99 53 •• .. 100 53 ily, and two wings, connected by covered passages with the centre, for various other purposes. The proportion that these wings should bear to the centre has never yet been ascertained ; yet every passing 18 INTRODUCTION. spectator will exclaim against the architect when the disproportion between the wings and the cenire strikes him as extravagant. In some modern build- ings of this nature we find the length of its wings in front, each only one third part of that of the cen- tre; in others, one half; but nothing has a worse effect than disproportion between the body and the wings in point of height. The connecting passage or colonnade always looks best when it forms exactly a quarter of a circle. The groat difficulty in architecture is to combine utility witli ornament and magnificence. This can, indeed, be properly done in structures of a certain extent alone ; but even space and expense have not always been sufficient to insure these essential ends. Excess of ornament is always misplaced in small buildings, which have then more the air of models of other great works than real places of abode. It was observed of Chiswick House, on the banks of the Thames, above London, (buUt in imitation, but on a small scale, of a noted structure of Palladio, near Vicenza, in the north of Italy,) that it was too large to hang to one's watch chain, and too small for a man to live in. DOORS. The size and proportion of doors must be regu- lated by the purposes of the building to which they belong. The door of a dwelling-house, correspond- ing to the human size, is confined to seven or eight feet in height, and three or four in breadth. In pri- vate hovises, four feet may be the greatest breadth. In small doors, the breadth or width may be to the height as three to seven ; but in large doors, as one to two. Doors intended to have but one leaf, or close, should never exceed three feet six inches in breadth, otherwise the door becomes too heavy for convenient use. Doors of a wider aperture, especial- ly in the outer wall, arc best formed with two fold- ing leaves. As to the modern fashion of opening a wide com- munication between rooms on the same floor, by means of broad folding doors, the practice sets all rules of proportion completely at defiance. The external lintels of doors and windows should always be on the same level, and the doors should never be narrower than the windows. When the outward wall is ornamented with half columns and arches, forming blank arcades, the doors and win- dows should just rise up to the springing of the arches. The most common way of ornamenting the aper- ture of a door is by an architrave on the top, and also down the sides. Sometimes a cornice and even a complete entablature may be placed above the lin- tel. Pilasters and semicolumns have also a good effect when applied to outer doors. Porticoes of four or more columns are properly adapted to large buildings. WINDOWS. The ininiber and size of the windows of a build- ing must be regulated by the nature and purposes of that building. The climate, the aspect, the extent, the elevation, even the thickness of the walls must be taken into consideration. When the walls are thick, which is commonly the case in detached stone buildings, the windows may liave a considerable opening inwardly, which will admit nearly as much light as if the whole aperture in the wall were en- larged. The proportions of windows depend on their situation ; only their width ought to be the same in every story — those in each, however, being proportioned in height to that of the apartments in each story. In the principal floor, the height of the windows may be two and one eighth to two and one thud of the width. In the ground story, where the apartments are lower, the apertures of the windows seldom exceed a double square ; that is, the height is just double the breadth. When the basement is riis- ticated, the height is generally much less. In the second floor, the height of the windows may be from one and a half to one and four fifths, or, rather, three fourths of the width. The window in the attics and mezzaninos or entresols may be a perfect square, or even lower. The windows of the principal floor are the most enriched. The simplest ornament of such windows is an architrave carried round the aperture, with a frieze and cornice on the top. The windows of the ground floor are sometimes entirely plain ; at other times they are surrounded with rustics or a regular architrave. Those of the second floor are generally closed with an architrave, crowned at times with a frieze and cornice ; but these last ornaments would be improper in the attics. The breasts of aU the windows on the same floor ought to be on the same level, and raised from two feet six inches to three feet above the floor. In warm climates, or in country houses in our own climates, seated amid gardens and pleasure grounds, the windows of the gi'ound story being cut dowi: to the floor, render the apartments pleasant and agreeable. In country houses, indeed, in France, Italy, and other warm parts of Europe, the principal apartments are aU on the gi'ound floor ; and the other floors diminish in height as they rise above it. The windows of the ground floor being cut down even with the doors, .and thus affording a ready communication with the garden or lawn, have a peculiar propriety. How far the same practice in the windows of the first and other floors, in the streets of large cities, by which the damps and cold of winter must inevitably penetrate into the apart- ments, ought to be avoided, is a point to be decided by those who prefer comfort and health to absurd- ities, however fashionable. Not contented with adopting usages suited to INTRODUCTION. 19 the genial temperature of the south of Europe, a stranger on passing along the new quarters of Lon- don might be tempted to imagine himself transported to the burning climates of India, when he beholds the fronts of the houses, whatever be their exposure, adorned, or, rather, loaded and bloeked up, with vast projecting galleries, intended, but very unnaturally, lo imitate the light, airy, and refreshing verandas of the East. In so far as these galleries are on the outside of ihe windows and walls, they are certainly of use to intercept the immediate action of the sun's rays. On the same account, what we call Venetian blinds ought to be placed on the outside, and not on the inside, of our windows. On the inside, they keep off the glare of the sun's rays, but not the heat, which communicates to the air of the room, warming it just as much as if no blind intervened. On the out- side, the blinds reflect and repel the heat as well as the light, and the au* within the room preserves a desirable coolness of temperature. The intervals of walls between windows should never be less than the aperture of the windows, nor in dwelling-houses gi-eater than twice that aperture, otherwise the light will be deficient. The usual rule for proportioning the quantity of light to a room is, to multiply the length of the room by the breadth, and the product by the height. The square root of the last product gives the number of square feet of aperture requisite for properly lighting the room. Thus, suppose a room to be in length 32 feet 6 inches, in breadth 24 feet, and in height 15 feet ; the product of these quantities multiplied successively into each other will be 1700 ; the square root of which, in even numbers, — 108, — will be the number of square feet of aperture required to lighten the room. This quantity, distributed among three windows, gives 36 square feet for each window ; the width of each being 4 feet, the height must be twice and one fourth, or 9 feet. Had it been proper to open four windows in the same room, each must have contained only 27 square feet ; and if the breadth of each were 3 feet 6 inches, the height would be 7 feet 8i inches. It is, however, to be observed, that both internal and external openings in houses, such as windows, doors, &c., ought always to consist of the uneven numbers, 1, 3, 5, 7, 9, &c., and never of the even numbers, 2, 4, 6, 8, 10, &c. This rule cannot always, it is true, be observed in the confined spaces allotted to houses in towns ; but in other situations, if the number of windows be even, the door cannot be opened in the centre of the building, and the want of an equal corresponding extent and balance on each side must strike the most careless spectator. The same rule is to be observed in distributing the arches of a bridge or an arcade, the intercolumniations of a portico or colonnade. The proportions of rooms, in length, breadlii, and height, arc more the objects of taste and experience than of geometrical regulation. A circle or a scjuare is a more perfect figure than an oval or a parallel- ogram ; and a globe, a cylinder, or a cube, than a parallelopiped. A room, however, in the form of a cylinder or a cube, would, in general, be neither useful nor agreeable. The parallelopiped is, therefore, the form universally adopted for rooms or chambers of every sort, in which the greatest dimension is the length, the next is the breadth, and the smallest is the height. Some architects have made the breadth one half more than the height, and the length one half more than the breadth. Thus, for example, if the height of the room be 16 feet, the breadth will be 24 feet, and length 36 feet ; and on the other hand, if the length be given, 22 feet 6 inches, the breadth will be two thirds of it, or 15 feet, and the height two thirds of the breadth, or 10 feet. Such a rule, however, must evidently be subject to many modifications. The rooms on the gi-ound or the second floor may be of the same length and breadth with those on the principal floor ; but if they were of the same height, the impropriety would immediately strike and offend the eye. No defect in proportion, however, is more offensive than that in the height, and none takes more off from the appearance of a room. A low apartment, whatever be its other dimensions, never can possess either dignity or beauty. It is the common remark of every one who, for the first time, enters the matchless fabric of St. Peter's, in Rome, that it by no means strikes the eye as so vast as it is known to be. This effect arises from the correct proportions of the whole edifice, in length, breadth, and height, and of the various members of which it consists. Had it been narrow, our attention would have been attracted to its great length. Had the ceiling been low, we should have been offended by its disproportionate length and breadth. Such, on the contrary, is the harmony of the several dimen- sions of the building, that no excess or defect in either of them leads us to institute a comparison be- tween them. It is only by observing the time neces- sary merely to walk round and give a cursory glance to the interior of St. Peter's that the stranger can be convinced of its prodigious extent in all directions. Comparisons are seldom pleasing, and not always just ; it would, therefore, be on many accounts unfair to compare St. Paul's of London with St. Peter's of Rome. It must, however, be acknowledged that the first view of the former has an effect very differ- ent from that produced by the latter, the chief cause of which is, that the nave of St. Paul's is really gloomy, and apparently narrow and low for its length ; so that the spacious and lofty dome, instead of being only accessory, becomes the principal part of the edifice. 20 INTRODUCTION. The proportions and dimensions of rooms must be reg^ated by their uses. A dining-room and a bed- chamber require very different proportions. A gal- lery for exercise in bad weather, especially if to be adorned with paintings and statues, must be of a length in proportion to its height and breadth, which last must be governed by the necessity of possessing light from windows on one side only, to exhibit with due advantage the paintings and sculpture ranged along the opposite side. A passage should be just wide enough to give a convenient communication betw^een the several parts of the house ; and if it be wider, we are offended with the waste of space which the architect ouglit to have turned to some other use. There is no part of a building in which the taste of a builder can be better displayed than in the position and distribution of stairs. Even in the most spacious buildings, a step may be made too broad, so as to require a sort of effort to move up or down from one to another. In spacious stairs, the steps should vary from 12 to 18 inches in breadth, and from 4 to 7 inches in height ; the length, also, varies fjom 6 to 15 feet. Even in small houses, a step over 7 or 8 inches high would be inconvenient ; and the breadth should never be less than 9 inches, nor the length shorter than three feet. We have thus given a pretty lengthy account of the theory of Architecture ; and would now invite the attention of the student to the subjoined remarks on the practical branch of the science. A competent knowledge of the methods of draw- ing on paper, and of working in stone, timber, or other materials, the several kinds or orders of col- umns, &c., is absolutely indispensable to enable the architect to discharge his duty to his employer, and the artisan to execute his commission. It has been already mentioned, that an order of architecture consists of three principal parts, viz., the column, its pedestal, and its entablature. Each of these parts is again subdivided into three parts, thus : the pedestal into its base or lowest member; the cubical body, called from its figure the die or trunk ; and the cornice above all. The column into the base, the shaft, and the capital. The entablature into the architrave, the frieze, and the cornice. To give a minute, full, and perfect explanation of the proportions and manner of constructing these several members, with the various ornaments apper- taining to each, would require an extent and a num- ber of engravings totally incompatible with the de- sign of Ihc present work. Nor is this particular explaiialion deemed essential; for the number of publications on this head is already so numerous, that it is probable the student will find it more diffi- cult to determine which to follow than to find a guide. Our obser\'ations will, therefore, be general and limited. The simplest problem in mechanical architectiu-e seems to be, to determine the best form for a column The length and the weight (that is, the quantity of materials in the column) being given, it is of impor- tance to investigate the form wliich affords the great- est possible strength ; but it is somewhat difficult to ascertain the precise nature and direction of all the forces to be resisted which act upon the column. If a column were considered only as a beam fixed in the ground, and acted upon by a force pressing trans- versely, or on one side, it ought to be much tapered, and reduced almost to a point at the upper end. But it is seldom that any force of this kind can be so powerful as to do more than overcome the weight of the column. The only thing, therefore, to be con- sidered, is the load which presses on it from above ; hence, whether we regard the force as tending to bend the column or to crush it, the forms commonly employed appear sufficiently eligible. Some math- ematicians have erroneously recommended the cyl- inder as the strongest form to resist bending ; and in this opinion, those who have not considered the sub- ject are ready to join them, because a cylinder, standing perpendicularly on one end, being of equal thickness, seems also to be of equal strength through- out. From the principles of mechanical philosophy, however, it can be shown that the strongest form of an upright column approaches, in fact, much more nearly to that of an oblong spheroid or spindle of which the outside is an arch of an ellipsis. But the consideration of the flexure of a column is of the less practical importance in architectvure, that, ixpon a rough estimate of the properties of the materials usually employed, a column of stone (in order to be capable of being bent by any weight which will not crush it) must be at least forty times as high as it is thick, although a bar of wood or of iron may be bent by a superincumbent load, if its length exceed about twelve times its thickness. But as, even in the Composite order, — the tallest and most delicate of all, — the height of the column is only, at the most, ten times the thickness at the base, the action of the incumbent weight, in bending the column, ceases to be an object of much consideration. It is only, then, as a crushing force that the weight requires to be estimated ; and since the lower parts of the column itself have not only the weight above, but its own upper parts, to support, the thickness below ought to be somewhat increased. It appears, by experience of the direction in which the fracture of a column is made when crushed by too great a weight, that the outline ought to be made a little convex, or to sweU a little on the outside of a straight line, joining the extremities of the shaft, and more curved above than below. This is the usual, but not the universal, practice. An elliptic arch is, perhaps, the most eli- gible outline, or a curve formed by bending a rule^ fixed at the summit of the column. It is very INTRODUCTION. 21 natural, in forming a column, to copy the working of nature in forming the trunk of a tree, which may be considered, in a general sense, as a portion of a tapering cone, enclosed by straight lines joining the top and the bottom. But, independent of other con- siderations, it is to be remembered that the great load of the boughs, branches, and leaves act upon the trunk of the tree very differently from the load usually to be borne by a column. A light-house placed upon a rock in the sea may be considered as a column erected, not to support a weight, but to withstand the action of wind and water. If we cal- culated what would be the best form for a wooden pillar, intended to remain always immersed to a cer- tain depth in water, we should find that a cone or a pyramid would possess the greatest possible strength for resisting the motion ,of water ; and a cone still more acute than this would be equally capable of resisting the force of the wind, supposing it to be less powerful than that of the water. The part be- low the surface of the water might, therefore, be widened, so as to become a part of a more obtuse cone, the upper part remaining more slender ; and the agitation of the sea being greatest at its surface, the basis of the pOlar might be a little contracted, so as to have the outline of the lower part a little con- vex outwards, if the depth of water were consider- able. But in the case of a building of stone, the strength often depends as much on the weight as on the cohesion of the materials ; and the lateral adhe- sion, which is materially influenced by the weight, constitutes a very important part of the strength. For resisting a force tending to overset the building, the form in which the weight gives the greatest strength is that of a conoid ; that is, a solid, of which the outline is a parabola, (a section of a cone parallel to its sides,) concave towards the axis, and convex outwardly ; and for procuring, by means of the weight, a lateral adhesion every where propor- tional to the force, the form must be cylindrical. Hence, in a building such as this pillar is supposed to be, no reasons appear why cither portion of its outline, taken separately, should be made convex towards the axis, although the joining of the two cones might very properly be rounded off. Of the form adopted for a building exposed to the violence of both water and wind, we have a remarkable ex- ample in the light-house erected on the Eddystone Rock, situated in the entrance of Plymouth Haven, about fom-teen miles out from the land. The top of the rock on which the light-house is founded is, it is true, constantly above the surface of the water when the sea is calm ; but in stormy weather, every part of the building is exposed to the action of the waves, the water being often thrown up to a height far above that of the light-house ; so that it may be con- sidered as exposed to the force of a fluid acting more and more forcibly as it is nearer to the foun- dation. On this account, the architect, the late in- genious Mr. Smeaton, chose for the walls a slope concave outwards, difl'ering in form but little from that which the most accurate theory could have pointed out. The building, however, is probably a little weaker nearly as high as the middle of its height than in any other part. The light-house is wholly composed of cut stone, and about 16 feet in diameter at the bottom. The height of the building is 73 feet 6 inches from the rock to the top of the cornice ; thence to the base of the lantern 7 feet 6 inches ; and thence to the summit of the ball on the top 17 feet 6 inches ; making the whole height 98 feet 6 inches. In diminishing their columns, various rules seem to have been practised by the ancient architects. Sometimes the diminution began at the base, the shaft being formed by straight lines tending to a junction at a point beyond the summit of the col- umn, by which measure the shaft became a frustum, or portion of a very acute cone. In other instances, we find the column carried up perfectly cylindric, or of the same diameter, for one fourth, or more com- monly for one third of its height, at which points the diminution begins, and extends to the capital. This junction, however, of the cylinder and the cone, although the angle formed by their outlines be al- most imperceptible to the eye, appearing an imper- fection, it was proposed and practised by eminent architects to form the outline of the shaft, by a curve running within the cylinder, but without the cone, from the base to the capital, in such a way that the diameter of the shaft was, in every part, less than that at the base, but greater than that at the capital. The observations made on this point by Vitruvius, the great teacher of architectural mechanics, who flourished about the beginning of the Christian era, having in late times been misunderstood, it is no uncommon thing, in different parts of Eiurope, (to say nothing of our own country,) to meet with col- umns, the outlines of which consist of a curve, actually swelling outwards, so that at one third of their height their diameter considerably exceeds that at the base — a practice so offensive to the eye, as weU as to reason, as to create wonder how it should ever be adopted by men who had ever seen, or even read, of the monuments remaining of ancient archi- tecture. The different methods of giving to columns the proper diminution and most elegant sweeping out- line are particularly described in the body of this work. In this place, we must content ourselves with giving the following plain instructions, by which every practical artisan may form his model and plan with accuracy sufficient for ordinary occasions : — Take the lower and upper diameter of the shaft of a column to be drawn. On the centre of the lower diameter describe a semicircle, and erect a 22 INTRODUCTION. perpendicular to represent the axis of a column. Through the extremity of the upper diameter draw a line parallel to the axis of the column, cutting the semicircle at the base. Now, divide the arc of the semicircle made by the intersection of the last-men- tioned line and the extremity of the base line into any number of equal parts, the more the better, as into 4, by points marked 1, 2, 3, &c. Li the same way, divide the axis into the same number of equal parts, through each of which draw indefinite right lines, at right angles, to the axis. Through the points of the arc, at the base, draw lines parallel to the axis, producing them respectively until they meet the transverse lines ckawn through on the axis, which will thus become points in the surface of the column. To assist in drawing these parallel perpen- diculars, it will be convenient, through the points in the arc at the base, to draw lines to the axis parallel to the diameter, and setting off a distance equal to one of these lines upon the transverse line passing tlrrough the first line. Another, equal to that of the second, the points of the axis will be obtained as before. The setting on the transverses through the first point, a distance equal to the extreme points : in this manner, the points on the opposite side of the axis may be obtained. K, now, nails or pegs be fijced in the several points in the surface of the col- umn thus ascertained, and along them and through the two extreme points of the upper and lower diam- eters a thin slip of timber, equally flexible in every part, be applied, it will show the contour or section of the exterior of the column. The curve thus formed, being carefully transferred, will mark the edge of the rule to be used in diminishing the shaft. In this process, it is evident that the more numerous the points of the surface ascertained, the more accu- rately will the slip of timber assume the proper form, and the diminishing scale be constructed. MOULDINGS. Although the shaft of a column may not admit of any ornament on its body, yet, at each end, in the base and the capital, various ornamental parts are introduced, in the due disti-ibution and proportion of which consists their principal beauty. These arc, in general, called mouldings, because they are always of the same shape, as if they all proceeded from the same mould or form. Mouldings are, by some writers, divided into Grecian and Roman, with a ref- erence to the remains of the architecture of those nations still in existence. The difference consists in this — that the Romans generally employed circular arches in their ornaments, while the Greeks often introduced parts of an ellipsis, or of some other sec- tion of a cone varying from the circle. The princi- ple parts of mouldings are these : 1st. The flat part under or above a moulding is 2i fillet, as resembling a bandage or turban tied round the column. 2d. When the moulding projects in the form of a quadrant or a smaller portion of a circle, it becomes an echinus or Romano ovolo, from its likeness to a portion of the shell of a sea-hedgehog or of a common egg. 3d. But if the moulding, reversing that figure, be a hollow of the same shape, it is, therefore, called a cave/lo. 4th. A small ])rojecting semicircular mould- ing is in general called a head, as particularly belong- ing to the astragal, or neck ; but, 5th. K the moulding be much larger, with a fillet above or below it, it then becomes a torus, as imitating a rope or cable applied to the column. 6th. If the section be a con- cave semicircle, or scmielLipsis, it becomes a scotia, because the interior is dark. 7th. When the projec- tion is not properly a part of a circle, but rather of an ellipsis, or of some other section of a cone, re- turning in quickly at the upper part, it is called a Grecian ovolo ; and the quick return in it is by workmen called a quirk. 8th. A contour or section, partly concave and partly convex, is a ci/matium, be- cause it imitates the waves of the sea. 9th. If the concave part be uppermost, it is a ci/ma recta ; but if the convex part be uppermost, it is a ci/ma reversa, or ogee. VOLUTES. A volute is a kind of spiral scroll, used in the Ionic and Composite capitals, of which it makes the principal characteristic and ornament. It has been called the ram's horn, from its figure, which bears a near resemblance to it. Most architects suppose that the ancients intended the volute to represent the bark of a tree, laid under the abacus, and twisted thus at each extreme, where it is at liberty. Others regard it as a sort of pillow or bolster laid between the abacus and echinus, to prevent the latter from being broken by the weight of the former and the entabla- ture over it. Accordingly, they call it jnthdnus. Others, after Vih'uvius, contend that it is designed to represent the curls or tresses of a woman's hair. The number of volutes in the Ionic order is four ; in the Composite, eight. There are also eight angu- lar volutes in the Corinthian capital, accompanied with eight other smaller ones, called helices. There are several diversities practised in the volute. In some the list or edge, throughout all the circumvolu- tions, is in the same line or plane. Such are the antique Ionic volutes, and those of Vignola. In others, the spires or circumvolutions fall back ; in others, they project or stand out. Again : in some, the circumvolutions are oval ; in others, the canal or one circumvolution is detached from the list of another by a vacuity or aperture. In others, the rind is parallel to the abacus, and springs out from behind the flowers of it. In others, it seems to spring out of the vase from behind the ovum, and rises to the abacus, as in most of the fine Composite capitals. INTKODUCTION. 23 The volute is a part of great importance to the beauty of the column ; hence architects have invent- ed divers ways of delineating it. The principal are that of Vitruvius, which was long lost, and at last restored by Goldman, and that of Palladio. DRAWING A COLUMN. In drawing a column of any particular order, the several dimensions and members are measured by a proportional scale, founded on the diameter of the lower extremity of the shaft, immediately above the projection of the base, where the shaft becomes rec- tilineal. This diameter is divided into t^vo equal parts, each being the radius of the transverse section of the column, and it is termed a module. The whole diameter is subdivided into sixty equal parts or minutes, of which, consequently, thirty are con- tained in a module. These proportional quantities are easily converted into real when the lower diam- eter of the column is given in measure. Thus, if the lower diameter of a Doric column be 5 feet, or 60 inches, the module must be 2i feet, or 30 inches, and each minute will be 1 inch ; and the Doric column being in height 8 diameters, the height of the given column will be 40 feet : hence the entablature, being one fourth of the height of the column, its height in this case will be 10 feet, and so on. Li the Tuscan order, the height of the column is 7 times the lower diameter, or 14 modules ; the entab- lature one fourth of the column, and pedestal one fifth of the height of all the parts. Hence, let the whole height of a Tuscan column, with its pedestal and entablature, be fLxcd at 40 feet, the pedestal, being one fifth of the whole, will be 8 feet high. The remaining 32 feet, divided by 5, will give nearly 6 feet 5 inches for the entablature, and 25 feet 7 inches for the column, of which the lower diameter, being one seventh, will be nearly 3 feet 8 inches. Had the order been Ionic, the whole height, 40 feet, divided as before by 5, (for, in all the orders, the ped- estal is always one fifth of the entire height,) would have given 8 feet for the pedestal, and the remaining 32 feet, divided by 6, would have given 5 feet 4 inches for the entablature, leaving 25 feet 8 inches for the column, of which the ninth part, or 2 feet Hi inches, is the lower diameter. But, in general, when the whole height of the column, with its pedestal and entablature, is given, the several portions are thus found in all the orders. For the Tuscan, divide the entire height by 5 ; the quotient is the pedestal, and the remaining height, divided by 5, wiU give the entablature. The remainder, divided by 7, gives the lower diameter of the column. In the Doric, divide the whole height by 5, for the pedestal ; one fifth of the remainder is the entablature, the rest is the col- umn, of which the eighth part is the diameter. Ionic — deducting from the entire height one fifth for the pedestal, one sixth of the remaining height is the entablature, and one ninth of the remainder is the diameter of the column. CORINTHIAN. After cutting off the pedestal, as before, the entab- lature is one sixth of the remainder, as in the Ionic ; and one tenth of the rest is the diameter of the col- umn. For the Composite order, the same proportions are employed. In laying down any order on paper, draw a perpendicular right line to represent the axis of the column. Near the bottom, draw another line (horizontally) at right angles, on which, from the perpendicular, set off on each side a distance equal to a module, on one half the diameter. On a sep- arate line equal to this diameter form a scale of sixty equal parts or minutes, by which to measure all the dimensions, reducing them to minutes from the num- ber of feet and inches in which they are usually given. The construction of such scale is, however, generally unnecessary, from the variety to be found on Gunter's and other scales of wood, brass, &c., sold by the makers of mathematical instruments. On the axis of the column produced below it, set off, progressively downwards from the bottom of the col- umn, the heights of the several members composing the base and pedestal ; and through each of those points draw pencil lines at right angles to the axis. Again : from the same bottom line of the column set up along the axis the several heights of the cap- ital, architrave, frieze, and cornice, drawing, as be- fore, lines at right angles through each point thus ascertained. Then, from the axis, set off, on each horizontal line, the proper projection of all the sev- eral parts in order, by which means the true elevation and projection of each \viU be obtained. The ex- tremities of these horizontal lines are then connected by the fillet, the ovolo, cyma recta, &c., according to the kind of ornamental profile belonging to each par- ticular order of architecture. The relative proportions of the various parts of the orders being accurately marked on the plates, any account of them here might be regarded as a work of supererogation. A specimen of the Composite order, singularly rich and beautiful, exists at Rome, in the triumphal arch erected to commemorate the awful and pre- dicted destruction brought upoia the city and temple of Jerusalem by the Romans, in the year 70, under Titus, during the reign of his father Vespasian.* * The remains of this triumphal arch stand very near the south- western limits of the ancient Forum. They are thus noticed by Theodore Dwight, Esq., in the Journal of his Tour in Italy : " It (the arch) is built with solidity, of large blocks of marble, in the form of a simple gateway ; but the deep channels worn into its sur- face by time, and the immediate historical connection it has with the overthrow of Jerusalem, have imparted to it a moral grandeur which even superior antiquity or magnitude alone could never 24 INTRODUCTION. Under the arch are sculptured the golden candela- brum of seven branches, the tables of showbread, and other spoils carried away from the temple. It is the ingenious, and not improbable, fancy of some eminent ^^Titers on architecture, that the general idea of the Composite order, as it appears in the Arch of Titus, was borrowed by some Roman artist in the suite of that general from the structure of the Tem- ple of Jerusalem itself, after the conquest of the city, but before its final overtlirow. Josephus, it is trvie, says the columns of the temple were Corinthian ; but the dilTerences between that order and the Com- posite might not attract his attention, nor would they have been generally deserving of notice. At any rate, the triumphal and tropheal Arch of Titus is the most ancient monument in which the Composite order is discovered. This arch possesses another peculiarity, that it is supposed to be the first struc- ture of the tropheal or triumphal kind erected by the Romans — an example soon afterwards imitated by the abject adulation of the people, or, rather, by the insulting vanity of their princes, until at last such trophies, being lavished without discrimination, ceased to be marks of honorable distinction. The feelings and duties of human beings in a social state of existence natiurally spring from that state. To a person brought up from infancy in abso- lute solitude, such feelings would only produce mis- ery, and such duties would be a nonentity. Let, however, two persons be placed in mutual commu- nication, and that instant feelings of kindness or dislike, of affection or hatred, will arise. Let both be hungry, and let an apple or an orange only be procured ; this each will instinctively desire to appro- priate to himself, for an equal distribution of the object of their desires between them must be the possess. Those who have read the Scriptures &om infancy, and been taught to mourn with the saints and prophets of Israel over the des- olation of the city of David and the house of God, can never ap- proach, unaffected, and regard this monument of heathen triumph. As we entered the shelter of the arch we trod the stones of the old Sacred Way, which lay yet undisturbed under our feet — prob- ably the same pavement that Titus passed over in his triimiphal march to the Capitol, when they brought the spoils of the Holy Temple and a largo company of Jewish captives. On the right are seen, beautifully sculptured in relief, the seven golden candlesticks, the silver trumpet, the table of showbread, and the book of the law, all borne by priests marching in order ; and on the other side is the emperor in his triumphal car, drawn by four horses harnessed abreast, and represented with the highest skill of the sculptor. The chariot is accompanied by the Genius of the Senate and Victory, bearing a crown of a branch of palm from Palestine. This record of history, containing more details than I have enumerated, still speaks to the eye and to the mind in language as clear and impres- sive as when it was first erected. But the unyielding spirit of the captives retains, to tliis day, all its pride .ind sternness. There are many Jews now in Home, the descendants of the prisoners of Titus ; but it is said that not a son of Israel has ever passed this detested Bpot, and trodden this part of tlic Sacred Way, since the day of his triumph. They still delight to trace back their pedigree to those whose humiliation they have inherited ; while, it is said, not a man in being can establish a clear and undoubted claim to the blood of any ancient Roman family." result of posterior experience and reflection, and not the spontaneous suggestion of the occasion. If the one is a little stronger or more alert than the other, he w'\\\ avail himself of these advantages over his fellow-being to seize the object of his wishes. By this sole appropriation, the other sustains not an imaginary, but a real, loss. The natural desire for necessary aliment will aggravate his feelings of dis- appointment and defeat into aversion, resentment, and revenge against his spoiler ; and should lie be frequently thwarted in a similar way by his com- panion, notliing short of the entire destruction of that companion will appear sufficient to secure him- self from future privations and sufferings. This process will take place in the breast of the weaker being, even although the stronger should not attempt to assitme to himself still greater advantages, in consequence of his acknowledged superiority. That the latter will, however, be governed by sentiments so moderate, is extremely improbable. Tlie self- gratulation arising from consciousness of power wiU yield a flower too delicious not to induce the desire of again experiencing such delight. He will thus naturally be disposed to exercise his superior faculties, not when the calls of necessity only, but when the suggestions of vanity or caprice, may fiu-- nish opportunity. Hence, his feebler neighbor will, by degrees, be reduced to absolute slavery, depend- ent on the other for even the necessary means of existence ; and of this existence itself, should he long continue refractory, he will probably be at last deprived. Thus may be traced the origin of the worst feelings and actions by which human beings are distinguished ; and by a similar, bttt opposite, process, may the rise and progress of the best senti- ments and conduct be explained. In absolute se- questration and solitude, neither virtue nor vice can exist ; but without virtue and vice in society, human beings can have no existence. When this simple and obvious theory of what is called the origin of evil (a theory by far too simple and too obvious to have fixed the attention of presumptuous philosophy in any period of the world) is considered, it will ex- cite no surprise that the history of mankind, imder even the most favorable circumstances, sliould pre- sent little else than an endless chain of deplorable wickedness and WTctchedness, equally the natural consequences of folly and vice. " We are a con- temptible gang of plunderers, pests of society, mer- iting, forsooth, punishment the most severe and dis- graceful, because we appropriate to ourselves the property of unoffending men, and even, on some occasions, deprive the owners of life ; and all this we do, few in number, more frequently by secret strat- agem than by open force, and even in some measure authorized by the sanction of necessity. Thou, on the other hand, born to independence, to wealth, to power, to supreme dominion, without even a rival to INTRODUCTION. 25 attempt to obstruct the gratification of thy desires, without provocation, without invitation, without ne- cessity, without any motive or reason which a man of genuine coru'age and truth, a friend to human kind, would avow ; thou destroyest cities, the abode of in- dustry, knowledge, and patriotism ; thou layest waste peaceable and flourishing countries, where thou hast received no injury ; thou causest to flow torrents of the blood of nations who never even heard of thy name ; and all this thou dost at the head of armed myriads, in open defiance of common justice and hu- manity ; therefore art thou exalted to the rank of a hero, a conqueror of worlds, a demigod." In such a strain, we are told, was the mighty Alexander of Macedon addressed by the chief of a petty band of pirates who fell into his hands, and whom he con- ceived himself autliorized to punish, in an exemplary manner, for their outrages on society ; and the obser- vations are fully warranted by the undeviating prac- tice of aU people and of aU times. Hence, we find in the most ancient records of human society ap- plause and reward lavishly bestowed on the successful warrior, whether just or unjust the cause in which he was engaged. But, beside tliis and other marks of the real or supposed admiration and gratitude of their armies and people, conquerors were in the habit of constructmg some more substantial evidence of their victories on the scene of their exploits. At one time a rude block of stone, at another a mould or liillock of stones and earth, raised on the field of battle, served at once to point out the spots where the honors of the victor were achieved, and where rested from their toils the human beings thus cut off in the performance of the duties he imposed. Of such monuments many examples still survive the long lapse of ages, in Great Britain — in Cornwall, in Wales, and in Scotland. These dumb memorials came at last into disrepute ; they recorded, indeed, a slaughter and a victory ; but succeeding generations, when tradition grew feeble or entirely died away, were left to conjecture the cause of their erection ; and the mighty warrior was thus bereft of half his glory. When the Romans began to establish them- selves in the southern parts of Gaul, and to extend the boundaries of their province, now Provence, Lan- guedoc and Dauphiny, in France, they first constructed durable memorials of the success usually accompany- ing the exertions of united and well-disciplined bands, although far firom numerous, against countless mul- titudes of irregular, ungovernable barbarians. Two Roman generals, Domitius ^nobarbus and Fabius Maximus, erected on the banks of the Rhone, saxosw turres, towers built of stone, supporting trophies, con- sisting of arms offensive and defensive, standards, instruments of martial music, and other pledges of victory taken from the ancient CJauls. This conduct on the part of their commanders was highly reproved at Rome ; for untQ then the Romans had never al- 4 lowed themselves, even after their most signal success in war, to erect, in the midst of a conquered people, any monument whatever, by which they should be reminded of their subjection, and, consequently, be ex- cited to endeavor to regain their former independence. " Never before this," says the historian, "did the Ro- man people upbraid any conquered nation with their own defeat." This happened about one hundred and twenty years before England's era. Some time after- wards, Pompey constructed, on the summit of the Pyrenees, near their eastern extremity, a permanent building, as a memorial of his successes, slight enough, indeed, over the partial but patriotic attempt of the Spaniards to throw off" the Romish yoke. This ac- tion was severely reprobated at Rome. The same magnanimous sentiment actuated not the free states of Greece only, but even the despotic and military kingdom of Macedon. " States and nations," said those ancients, "like individuals and families, will differ upon particidar points, where their interests, real or supposed, are concerned. These differences will lead to quan-els, and even to the most hostile proceed- ings and opeir warfare. It is not unnatural that, in these contests in arms, the victors should endeavor to confirm the courage and ardor of their own people, and to depress the spirit of their adversaries, by some public testimony of their superiority. For such a pur- pose, a few helmets, and breastplates, and shields, and swords, taken from the vanquished and supported against a spear, or suspended on a tree, on the scene of victory, will be fidly sufficient : let not, however, such emblems of superiority be of long duration. The passions of men will cool, their views of interest will change, and the parties which to-day meet with deadly rancor in the field will be found in a short time united in one common cause, and fighting, as friends and brothers, against an ally of one of the parties on a former occasion, but now become a com- mon foe. It is, besides, to be considered that suc- cess in war is not always attached to one side ; no nation was ever always victorious, nor always dis- comfited. Let us never, therefore, by permanent rec- ords of our temporary superiority, labor to cherish and foment among oiur neighbors that spirit of hostility which, at no distant day, it may be equally our de- sire and our interest entirely to extinguish. Lijuries men often will, and do, forgive ; insults, perhaps, never." Such were the wise and magnanimous sen- timents and principles of the Greeks and Romans, the two most enlightened nations of antiquity, in their best days. In the degenerate days of Titus and Ves- pasian, however, when Rome reigned paramount over the greater portion of the civilized world, the feeling of national importance and independence, the source and support of every manly, generous, and patriotic principle, was next to extmct in the nations of Eu- rope. The example set in the case of Titus was speedily followed ; and not only Rome itself, but D. H. HILL LfBRARY North Carolina Stafe College 26 INTRODUCTION. numbers of tlie principal cities over the empire, were adorned with edifices, triumphal, tropheal, and com- memoratory, many of which stiU remain, exhil)iting admirable specimens of architecture and sculj)ture, and, by the inscriptions and representations with which they are charged, serving to illustrate and establish the dates of laiany important historical facts. Wis- dom, justice, and moderation arc immutable ; and, as such, never (let weak, and consequently narrow- minded, men say what they may) can be inexpedient or out of season. Human nature is, at this day, what it was twenty centuries ago. Let, then, the prudence and humanity by which states were then governed, and not the overbearing presumption and insolence on the one hand, and tlie abject, interested adulation on the other, by which later periods have often been characterized, suggest the most commendable models for modern imitation. But to return to the jVixh of Titus. It may be just to add, that the unfortunate branches of the Hebrew nation established in Rome made an arrangement, many years ago, with the government, agi-eeably to which, for the payment of a certain sura of money, they were permitted to open a naiTow passage by the side of that arch, which, although not now connected with the inhabited part of the town, is situated in the heart of the old city, on a very public thoroughfare, that then- minds might not be tortured unnecessarily by the display of the emblems of the final dcsti-uction and extinction of their religion and their state, of their name and their nation. This digression the reader will, it is trusted, without difficulty pardon. It arose natm-ally from the subject, and may, per- haps, suggest certain considerations not entncly un- profitable. With respect to the kind and degree of ornaments to be introduced into a column and its appendages, it is a maxim, founded in our natural sentiment of what is decorous and beautiful, that if we are in doubt concerning the proper medium, we should al- ways stop short of the proposed point, and be careful never to go beyond it. The pupU of an ancient painter in Greece produced a Venus loaded with jew- els. " Unable to make the goddess bcautifid," said his master, " you have thought to atone for that de- fect, by making her rich and fine." The dignified sobriety and gravity becoming an edifice appropriat- ed to religious purposes or to the senatorial and legislative assemblies of a great and enlightened peo- ple; the massive solidity and strength inherent in our idea of a forh'css; the light, airy, exhilarating notion attached to the name of a theatre or other places of amusement, — all these qualifications of the edifices to be conslrneted will, to an architect of genius, suggest the species and (he measure of the ornament suitable to each. A slender, delicate, and highly-enriched Corinthian portico to Newgate prison could not be more incongruous, nor indicate a greater want of taste in the builder, than a massive, heavy, clumsy Doric (if Doric it be) range of pUlars, and their pedi- ments coiTcspontUng — apparently forbidding, but doubtless meaning to invite, the passing sh-anger to enter the theatre of Covcnt Garden. When we ex- amine the monuments remaining from antiquity, we find that the cyma, the cavetto, or other ornament, formed by cutting into the substance of the work, is employed as a finishing only, and never where strength is required ; that the ovolo and talon are employed to support the essential parts of the entab- lature, such as the modillions, dentils, and corona ; that the principal use of the torus and astiagal is to secm-e and strengthen the extremities of the columns, being also employed for the same purpose in pedes- tals, carved so as to resemble a rope or cable, agree- ably to the original signification of the term torus ; that the scotia serves merely to separate the members of the base, as does also the fillet, not only in the base, but in profiles of all kinds. By the term pro- file, is here meant the assemblage of parts, mouldings, and ornaments of a cornice, &c., in which the eleva- tion and projection of each member are exhibited. The most perfect profiles are those consisting of the fewest mouldings, adapted to the order of the column, so disposed that the right lined and the cm-vcd mem- bers succeed one another alternately. In every profile one member should be predominant, to which all oth- ers must appear subordinate : thus, in a cornice, the corona is the chief member, the cyma of the cavetto covers and defends it from the rain, while the modil- lions, dentils, ovolo, and talon serve to support it. In the arrangement of the exterior of a building, whatever does not tend to characterize its destina- tion, however beautiful in itself, is always misplaced. Greatness of character in an edifice is principally produced by largeness and simplicity of parts ; such parts, not only by their own magnitude, but by the gi-eat masses of light and shade tliey exhibit when fully illuminated, excite the idea of grandeur. An object may be gi'cat, and not be grand ; but gi-andeur and smallness of parts are incompatible. One of the most extensive edifices in Europe is the King of Spain's palace, at the Escurial, not far from Madrid. It covers a vast extent of gi'ound, enclosing a number of courts, porticoes, chapels, &c., in its bosom. Hav- ing, however, been constructed as a monastery rather than as a palace, (for the royal apartments are con- fined to a very small portion of the structure, the building is divided into various floors, and conse- quently, the exterior walls are pierced with various ranges of comparatively small windows, adapted to the cells and halls of monks. The consequence of all this is, that the idea of grandeur and magnificence raised in the mind of the spectator, while approach- ing it from a distance and observing its prodigious dimensions, entirely vanishes away, when, on a closer view, the whole is discovered to be only an assemblage INTRODUCTION. 27 of small diminutive parts and members, such as might be suitably introduced into a manufactory, a barrack, a hospital, or a convent. Many objections have been made to Blenheim Palace, in Oxfordshu'e, England, as clumsy, ponderous, inelegant, and by no means corresponding to the customary notion of a country residence. That magnificent edifice was erected, at the expense of the nation, to commemo- rate the signal victory obtained in 1704, near Blen- heim, a village on the north bank of the Danube, by tlie allied army, under the Duke of Marlborough. That distinguished and modest commander stands, next to Julius Ctesar, unrivalled in history for perfect coolness and possession of himself in action ; who, so far from ever exposing himself to the possibility of being svu-priscd, whatever might have been the talents of his opponent, never rested until he was so close upon the enemy as, in many cases, to discover their measures, and prevent their forming any project against himself for the greater part of the campaign. Like Cirsar, also, in person a hero, he was scrupu- lously tender of the lives of his men, and, to spare them, would often forego the opportunity of a bril- liant, but sanguinary and i;seless victory, for the more slow, but more secure and difficult advantages to be obtained by a sldlful occupation of ground. On a due consideration of the destination of Blenheim, it will be manifest that the architect, Sir John Vanburg, intended, by throwing the structure into a variety of large, projecting, and retmng masses of building, to produce broad and powerful eflccts of light and shade, and by that contrivance to fill the spectator with the idea of the vast magnitude of the parts and of the whole far beyond what their real magnitude, considered as it is, could be expected to excite. Besides regular columns and pilasters, we some- times meet, in ancient and modern architecture, en- tablatiu'cs supported by human figures. These are termed Cari/atidcs, from the following circumstance : Five hundred years before our era, Xerxes, the power- ful monarch of Persia, led a prodigious army and fleet against the free and independent republics of Greece. Successful at first, more by treachery than by valor, he was at last discomfited at every point, and compelled to return in disgrace and ruin to his own country. Carya, a town of Peloponnesus, had basely formed a league with the invader ; and upon his flight it was besieged by the other states, levelled to the ground, the male inhabitants put to the sword, and the unhappy, perhaps innocent, females reduced to slavery of the severest land. To perpetuate to future ages the infamy and punishment of the people of Carya, in Athens, and in many other parts of Greece, buildings were erected, in which were intro- duced, in the place of columns and pilasters, figures of Caryan women supporting the load of a cornice and entablature. In general, these figiu-es are at- tached, like pilasters, to the wall ; but in Athens they arc also found detached, and performing the duty of columns. Male figures are also employed in the same way in some ancient buildings in Greece and in Rome ; in Greece, they are evidently intended to represent Persian prisoners taken from Xerxes. From this account, it is evident that human figures, in the place of columns or pilasters, ought, if at all, to be introduced on very particular occasions indeed. They nevertheless are often seen in the palaces of princes, and even in private dweUmgs. Our churches themselves, in which all adventitious distinctions among mankind ought, if any where, to disappear, are not free from this absurdity. These poor females, humiliated, borne down with a heavy load, are meant, we are to understand, for the Muses and the Graces, the Vu-tues, and the Angels themselves. Could the vices which corrupt, and the furies which torment, the human race be thus chained down, and so rendered in some sort subservient to our use, such an applica- tion of Persians and Caryatides might easily be reconciled to reason. Not only entire human figures, but simple busts, are also employed, occasionally, to support the entab- latiues of monuments, chimney pieces, &c. The head is placed on a stand, smaller below than above ; and the whole is called a term, from terminus, a boundary, the Roman name of the landmarks or march stones erected on fields and possessions to point out the boundaries between the lands of differ- ent proprietors. The protecting charge of these land- marks, as of every thing else connected with the affaks of industry and commerce, being intrusted to Mer- cury, by the Romans as well as the Greeks, the top of the stone or post was carved in resemblance of his head ; so that to destroy, or remove, or deface such monuments was regarded not only as gross uijustice to men, but as a voluntary and impiovis offence against the powers above. It now remains to give a few observations on the constructions of bridges, one of the most important and difficult applications of architectural skill. CONSTRUCTION OF EraDGES. By a bridge, we mean a structure of stone, brick, timber, or iron, erected over a river, a canal, a vaUey, or other depression in the ground ; and supported on piers and arches, or on posts, for opening a communi- cation for passengers, cattle, and carriages across from the one side to the other. The perfection of a bridge consists in its having a good foundation, that it may be dm-able ; of an easy ascent and descent, that it may be convenient ; and of a just proportion in its several parts, that it may be beautiful. Bridges should always be placed at right angles to the course of the river, &:c., and the piers should never be thicker than is just necessary 28 INTRODUCTION. to support the structure against the force of the current. The simplest theory of the arch supporting itself in eqiiilihrio (that is, in such a state that the ten- dency of every part to fall down or give way is per- fectly equal) is that of Dr. Hookc, the greatest of all philosophical mechanics, who flourished in tiie latter part of the seventeenth century. The arch, when it has only its own weight to bear, may be considered as the reverse of a chain suspended freely at each end ; for the chain hangs in such a form that the weight in each link is held in equilibrio by the result of the tsvo forces acting at its extremities. Two forces, or tensions, are produced, the one by the weight of the portion of the chain below any particular link, the other by the same weight, increased by that of the link, both of them acting originally in a vertical direction. Now, supposing the chain inverted so as to constitute an arch of the same form and weight, the relative situation of all the lines indicating the direction of the forces will remain the same, the forces acting only in contrary directions ; so that they are compounded in a similar manner, and balance each other on the same conditions, but with this dif- ference, that the equilibrium of the chain is stable, and that of the arch is tottering. When the links are supposed to be infinitely small, and the curvatiu-e of the chain is greatest in the middle, the chain forms what is called a catenarian curve, from catena, a chain. In common cases, this form of an arch differs but little from a circular arch of about one hundred and twenty degrees, or one third of a whole cncle, rising ftom the abutments, with an inclination of thirty degrees to the perpendicular ; the arch, however, be- comes more curved at some distance below the sum- mit, and then again less curved. The supposition, however, of an arch resisting a weight acting only in a vertical dhection, is by no means perfectly applica- ble to cases usually occurring in practice. The pres- sure of loose stones and earth, moistened as they gen- erally must be by rain, is exerted very nearly in the same manner as the pressure of fluids, which act equally in all directions; and even if the stones and earth were united in a solid mass, they would consti- tute a sort of wedge, and produce a pressure of a similar nature. A bridge must also be so calculated as to support itself without being in danger of fallmg by the de- fect of the lateral adhesion of its parts. Li order that it may, in this respect, be of equal strength throughout, the depth at each point must be propor- tional to the weight of the parts beyond it. This property belongs to the logarithmic curve alone, the length being made to correspond with the logarithm of the depth. But, in the construction of bridges, it is necessary to inquire what is the best form for sup- porting any weight which may occasionally be placed on the bridge ; in particular, on its weakest part. which is usually the middle of the arch. Supposing the depth at the summit of the arch and at tiie abut- ments to be given, it may be considerably reduced in the intermediate parts, without impairing the strength; and whether the road along the bridge be horizontal or a little inclined, it is agreed that an elliptic arch, not differing much from a circular, is the best calcu- lated for complying, as much as possible, with all necessary conditions. The tier of bricks cut obliquely, which is placed over a door or window, is a real arch, but so flat as to allow the outline to appear horizontal. Little dependence, however, can be placed on so flat an arch, since it j^roduces a lateral thrust, that might easily overpower the resistance of a side wall. For the horizontal force required to support each end of an arch is always equal to the weight of a quantity of the materials supported by its summit, supposed to be continued of their actual depth, to the length of the radius of the circle, of which the summit of the arch is a portion. This simple calculation will enable an architect to avoid such accidents as but too often happen to bridges for want of sufficient firm- ness in the abutments. Very eminent modern arclu- tects have sometimes been less successful in con- structing arches of bridges and other edifices than those of former times, whom it is but too common to despise ; and, for want of attention to mechanical principles, they have committed such errors in their attempts to procure an equilibrium as have been followed by the most mischievous consequences. Examples of this mismanagement might be pointed out in the bridges of our own country, and the churches of others ; but if we are masters of the true nature and action of pressure, we shall be able to avoid similar errors, unless some defect in the mate- rials, the foundation, &c., occur, Avhich could not be foreseen. It is desirable that the piers of bridges should be so firm as to be able not only to support the weight of half of each adjoining arch, but always to sustain the side thrust of one of them, should the other give way. The same condition is necessary for the sta- bility of walls of any kind employed in supporting an arched or vaulted roof; hence the utility of the external buttresses, which strengthen and adorn Gothic structures. There are two w^ays in which a pier or a wall may give way ; it may either be over- set, or caused to slide away horizontally. But since the friction or adhesion ■which resists the side motion is usually greater than one third of the pressure, it seldom happens that the whole thrust of the arch is so oblique as not to produce a sufficient vertical pressure for secm'ing the stability in this respect', and it is only necessary to make the pier heavy enough to resist the force which tends to overset it It is not, however, the weight of the pier only, but that of half of the arch which rests on it, that resists INTRODUCTION. 29 every effort to overset it ; and, in order that the pier may stand, the sum of these weights acting on the end of a lever, equal to half the thickness of the pier, must be more than equivalent to tlic horizontal thrust acting on the whole height of the pier. The pier may also be considered simply as forming a continuation of the arch ; and the stability will be preserved as long as the curve indicating the direc- tion of the pressure remains within its substance. The dimensions of the piers must depend on the size and form of the arch, as also on the force of the current to be opposed. In tide rivers, the current acts twice a day in contrary directions, rising consid- erably above the surface of the river itself, and re- turning to that level. The pressure on the piers is, therefore, very unequal ; and, from the circumstance that the stones must be thus in a continual alteration between wet and dry, the selection and placing of the materials becomes a matter of the greatest im- portance. Some persons are of opinion that blocks of stone resist the action of water and sun, of wet and dry weather, best, when placed exactly in the same position as when they lay in the quarry. Whether this circumstance, if real, was attended to or not in the construction of Blackfriar's Bridge, in London, or whether the stone was of an improper kind, it is certain that such parts of the piers as are exposed to be covered by the tide are now in a state of manifest decay, while the corresponding parts of Westminster Bridge are comparatively but little affected, although it was founded in 1738, and the former bridge not till 1760. The new Strand Bridge is built of granite, the least svibject to decay of all stone from external causes. The stone employed in constructing the grand quay along the front of the arsenal of Woolwich, in England, was drawn from the vicinity of Dundee, in Scotland, and is found to answer much better in such a situation, where it is alternately, with short intervals, wet and dry, than any formerly employed. It has been likewise used in some of the great basins and docks in London, and in constructing the piers to support the iron bridge over the Thames, at Vauxhall. In building a bridge, the most essential part of the enterprise is to secure a good foundation. The most simple method of doing this, and carrying up the piers to the ordinary height of the water, is to turn the river out of its course, above the position of the bridge, into a new channel opened for it, near the place where it makes an elbow or bend, or by raising an enclosure round the spot where the pier is to be buUt, to keep out the water, by driving a double row of piles into the bed of the river, very near one another, with their tops above the siurface of the water. Hurdles are then put within this double row of piles, the side of the row which is next the intended pier is closed up, and the hollow between the rows filled with rushes and mud, so closely rammed down that water will not pass through. The mud, sand, stones, &c., within this enclosure, are dug out, until a solid foundation appears. When such a foundation cannot be found, one of wooden piles, having their lower ends well charred to prevent rotting, and driven into the bottom of the river as close together as possible, must be made. Some architects have formed a continued foundation the whole length of the bridge, and not merely under the piers. In doing this, first one part of the river is excluded, and then another, until the whole foun- dation be laid. When a river is but of moderate depth, having such a bed as may serve for a natural foundation, capable of bearing, without subsidence, in whole or in part, a heavy pier, then a strong frame of oak is constructed, and kept upon the surface by boats around it. On this frame is laid a thick stra- tum or layer of stone, cramped together by iron bars, and united by strong terras mortar, the whole of which, being then specifically heavier than the water, is suffered gently to sink down to the bottom, where the pier is to stand. If it be required to construct a bridge across a fordable river, or a canal, where the covu'se of the water may be turned off, either by a wooden fence placed obliquely across the river or by a channel dug one side, then a dam must be formed entirely across the stream, with pUes at a convenient distance above the place of the intended bridge. The ground is then dug out, until a proper solid foundation presents itself, and all the piers may be founded and raised up to the usual height of the river at the same time ; after which, the river is per- mitted to return to its original channel. When the stream is by far too considerable to be tiu-ned aside, coffer dams are formed, of a circular shape, to enclose the spot where each pier is to be built. The dam is made, as before said, by driving into the bed of the river a double row of stout piles, either charred at the lower end, when the bed is easily penetrable, or shod for several feet with ii'on where it is hard. The pUes are forced into the ground by repeated blows from the pile engine ; the piles are covered with boarding, without and within, so as to be tolerably water tight ; and the water which does make its way through the walls, or which springs out of the en- closed bed, is drawn off by pumps and hand labor, or, if the undertaking be considerable, by means of a steam engine. Besides bridges, other bodies of masoiu'y are also requisite, if not completely to transverse, at least to advance, a considerable way into the water. Such are the moles and piers carried out from the land into the sea, from opposite points of the shore, and mutually bending round towards each other at their extreme points, where they leave an interval suffi- cient for the passage of ships out or in. In our seas, where we have the advantage of the retreat of the sea twice a day, at low water such structures can be 30 INTRODUCTION. founded and carried up, in general, without partic- ular difficulty. In the Mediterranean, however, where the rise and fall of the tide is either very unimpor- tant or wholly insensible, — as along the coasts of Spain, France, Italy, &:c., — the construction of a mole becomes an enterprise of vast labor, difficulty, and expense. The work begins at the shore, by throwing into the sea blocks of rock or stone, the larger the more useful. These find thcii- place in the bottom, and, by accumulating block upon block over them, they at last rise above the surface of the water. The work being so far advanced, advantage is taken of the blocks above water to form a road, by which other blocks arc carried out and rolled into the sea beyond those akeady placed, and these again in their turn serve, when they come to the surface, to convey another succession of blocks, until the foundation of the mole be earned out to the intended extent. When we take into consideration the inequalities of the bottom of the sea, where not covered with hard sand, the incessant internal motion of the waters, produced by currents, to say nothing of the superficial agita- tion produced by the winds, that most rocks and stones lose a great part of theu- weight when im- mersed in salt water, — and are, consequently, more easily moved about from place to place by the mo- tion of the waters, — also the gi-cat extent in breadth to which rude blocks of stone or rock will necessa- rily roll before they find a bed, cither in the bottom of the sea, or on one another, — when all these things are considered, the structure of moles and piers in such seas must appear to be an enterprise of extreme difficulty and expense. In siich seas, however, no other mode of consti-ucting an artificial harbor can be devised. When the foundation is supposed to be sufficiently consolidated, and is raised above the aurface of the water, the mole is completed by a structure of hewn stone, founded in the interstices of the sunk blocks, adapted to the purposes of com- mercial and maritime affairs. Of this constriiction are the old and new models of Gibraltar, of Alicant, Tarragona, and Barcelona, in Spain ; of Sette and Toulon, in France ; of Genoa, Leghorn, Civita -^ Vecchia, Naples, and Anchona, in Italy, (S:c. The famous antique mole at Pozzuoli, in tlic Bay of Naples, is constructed with piers and arches founded in the sea, and is, fi-om its appearance, called Calig- ula's Bridge, having been, as is supposed, erected by that imperial monster. On the same principles with the moles just described is consti-uctcd what is called the Breakwater, in the enti-ancc of Plymouth Haven, in England, in the view of abating "the violence of the waves and currents which have, on many occa- sions, proved most prejudicial to the fleets resorting to that otherwise admirable station for shipping of every sort. In the report laid before the British Parliament concerning this prodigious enterprise, which was earned on at the public expense, the en- gineers, Messrs. Rennie and Whitby, (the former the engineer for the Strand Bridge, in London,) state that tliere are, properly spealdng, tliree entrances into Plymouth Sound or Haven, viz., one on the west side of the bay, bounded by a long cluster of small rocks, called Scott's Ciround, and the depth is only from 3 to 4 fathoms, (fi-om 18 to 24 feet,) at low water ; and on the east by the Knap and Panther, on which is about the same depth of water. This channel is about 500 fathoms wide, and the general depth is from 5J to 6 fathoms at low water. The middle channel is bounded by the Knap and Panther on the west, and by tlie Tinker and Shovel on the cast ; about 300 fathoms wide, and the general depth from 6i to 8 fathoms, at low water. From this description, it appears that a large part of the middle of Plymouth Sound is shut up by the Shovel and St. Carlos's Rocks ; that is, as a channel for large ships. Of com'sc, works erected on those rocks would be no obstruction to a passage in or out of the Sound. If a pier or breakwater were con- structed on the Shovel Rocks, and extended west- ward, so as to shut up in part the channel between them and the Panther, and also to shut up or narrow the spaces between St. Carlos's Rocks and Andurn Point, the tide being then confined to a naiTow space, the velocity of the current would be increased, and, consequently, the channels where it passed. It seemed, therefore, proper that a pier or breakwater should be constructed in the Sound, having its east- ern end about 60 fathoms east from St. Carlos's Rocks, and its western end about 300 fathoms west from the Shovel, forming, in the whole, a length of 850 fathoms. Of this pier, 500 fathoms in the mid- dle should be straight, and 175 at each end inclined at an angle of 120 degi-ccs. In addition to this breakwater, another should be extended fi-om Andurn Point, on tlie shore, towards the former, of about 400 fathoms in length, having also a part inclined at an equal angle. These inclined parts were to repel the waves in such a manner as to prevent them from passing violently through the opening between the piers, and to shelter tlie Sound within, so as to permit fifty sail of line-of-battle ships to ride at anchor in safety, in all winds and weather, and with ample room to work thek way out to sea, by one or other of the channels, as then- position and state of the wind might render most convenient. These great works were to be constructed by large blocks of stone thrown at random into the sea, in the line of the intended breakwater, to find their own bed. Stones from a ton and a half to two tons in weight would probably resist the swell of the Sound, in stormy weather. Where the water is five fathoms deep, the base of the breakwater should not be less than seven times that depth, or seventy yards in breadth, and ten yards broad, at a height of ten feet INTRODUCTION. 31 above the level at low water or ordinary spring tides. The slope of this foundation on tlio outer side, next to the sea, should be in tlic proportion of three yards horizontal for one yard perpendicular ; but the slope on the inside, next tlie Sound, would require an in- clination of only half that quantity, or one and a half yards horizontal for one yard perpendicular. To the project here described (and now completed) various objections were made, particularly by Mr. Bentham, who had executed some works at Shecr- ness, at the conflux of the Thames and the jNIedway, somewhat of the same nature, but in circumstances incomparably more easy to manage than in the open, stormy entrance at Plymouth Sound. He observed that such a work as that proposed by Messrs. Rennie and Whitby, even supposing sufficient precaution to have been taken to prevent any injury to the harbor during its execution, and that the whole were com- pleted in its gi'catcst perfection, would, nevertheless, by opposing throughout its extent a complete inter- ruption to the water, occasion such eddies in the wake of the work, and such an increased action on the bottom and sides of the parts left open, as could not fail of forming shoals, more or less injurious, according to the nature of the soil and other local ch-cumstances. Mr. Bentham's plan was to sink in the sea, but in a line of dkection difterent from that of the other engmeers, a double row of cylincbical masses of stone work, leaving an interval between each two masses above equal to their diameter; placing the masses in one row opposite to, and cover- ing the intervals between, the masses in the other row. By this an-angement, while the two rows in conjunction formed a complete obstacle to the dii-ect course of the waves, tlie tide or current would be allowed to pass freely between the masses, through- out the whole extent of the breakwater ; boats also, and even small vessels, might, in moderate weather, pass through the intervals without danger. Notwith- standing these objections and proi>osals, the scheme of Messrs. Rennie and Whitby, all circumstances duly balanced, was adopted by government, and or- dered to be earned into effect. On a plan much of the kind proposed by Mr. Bcnham, was begun in France, before the revolution, a project for forming an artificial roadstead, or place of anchorage for ships of war, in fi-ont of Cherbourg, on the north coast of Normandy. This place, situated in the bottom of a wide, open bay, on a part of the coast projecting considerably into the British Channel, lies only about sixty miles south from the Isle of Wight, and, tliere- fore, offers a most advantageous position for watching the motions of British fleets moving up and down the channel, or proceeding from or into the great place of rendezvous at Portsmouth or Spithead. Cherbourg possesses no natural qualifications for a shipping station, being merely a tide harbor formed by a small river falling into the sea. Basins ha->'e been excavated and locks constructed, in former times, by means of which frigates and smaller vessels could be conveniently protected ; all with uncommon ingenuity, and at a very moderate expense. It was not enough for an engineer in France to give proof of his genius and skill in his profession, in producing the best method of accomplishing any desired object ; his great merit consisted in inventing how to accom- plish that object in the most economical, as well as the most iiig-enious, manner. By giving this turn to the public mind, works of the highest importance to the state and to individuals were carried on, in that country, for sums which, in some other countries, would be regarded as utterly inadequate to the pur- pose. All persons charged with the execution of public works, even those we call civil engineers, em- ployed in the construction of harbors, bridges, canals, roads, &c., were military men, regularly bred, and under due but liberal control, enjoying rank and emolument sufficient for their station in society. An instance of a superior officer of the French corps of Royal Engineers suspected, accused, tried, and con- victed of recommending works which he well knew to be unnecessary, not to say prejudicial, that he might have an opportunity of enriching himself dur- ing theu- execution ; or of conniving at, not to say inventing, enormous abuses and extravagant expendi- ture, in the management of the public moneys, in order that he might be suffered, by the plunderers under him, quietly to amass his ti'easures ; that a field officer of engineers should be proved to have stooped so low as even to make false returns of the quantity of coals and candles necessary for his official busi- ness, — an instance of such degrading delinquency is unknown in the history of French military jurispru- dence. How far the same remark can be applied to another country, the constant rival, and often the en- emy, of France, the records of the courts which take cognizance of such offences against duty, honor, and even common honesty, will bear ample Ijut humiliat- ing testimony. As Cherbourg possessed no outer harbor or road such as Portsmouth possesses at Spit- head, it became necessary to enclose a portion of the bay to answer that purpose. Piers or breakwaters of continued construction were thought of; but at last it was resolved to sink a long range of wooden truncated cones into the sea at certain distances asunder, which, being afterwards filled with massy blocks of stone, would form a succession of solid, immovable masses, sufficient to break the violence of the external waves, and render the space within incomparably more quiet and secure than it was in its natural state. The cones were strongly com- pacted of oak, narrower above than below, and re- sembling a deep tub standing on its base, w^ithout a bottom. By most ingenious contrivances, the cones were floated out to their destined situations by means of empty casks, made air tight, which were afterwards 32 INTRODUCTION. detached, and the frame allowed to sink to the bot- tom. The sides were of sufficient height to be always above water, and, when filled with stone, withstood the action of the tide and waves. This great enterprise, the only thing of the kind in the world, was naturally interrupted by the disorders of the revolution in France, but was afterguards re- sumed with great activity, so that, in future wars with France, Cherbourg may become a most troublesome neighbor to Britain. WOODEN BRIDGES. Besides stone, timber is, on many occasions, em- ployed to open a communication across a river ; and in some cases it has greatly the advantage, as when the current is particularly rapid ; for there the posts or piles supporting the road, presenting, either indi- vidually or collectively, but a small obstacle to the stream, often effectually resist its violence, when a stone pier, if it could easily be constructed in such a position, would not long keep its ground. Hence it is, that not only in England, but more particularly on the continent, stone bridges over great rivers are comparatively rare. Thus, on the Rhone, for in- stance, which, rising in the highest Alps of Switzer- land, makes its way to the sea through the southern parts of France, bridges of stone have often been constructed, and as often carried away by the stream, so that at this day, perhaps, not more than two re- main. The Rhone is, however, the most rapid river of its size in Europe. On the Rhine, which, rising not far from the source of the Rhone, takes an oppo- site course through Germany and Holland into the German Ocean, and is so much less rapid as its course is longer, stone bridges are quite unknown. But this is owing not only to the great body of water it carries along, but also to the policy of the different states along its banks, each unwilling that the oppo- site state should, by a standing bridge of masonry, possess means of making hostile attempts across the river. At Strasbiu-g, for instance, a large and pros- perous city of Alsace, in France, seated on the west bank of the Rhine, commanding by its fortifications a much frequented passage over the river into Ger- many, the bridge is formed by ranges of pUes driven into the river to form the piers, supporting rafters and planks for the road, kept in their place by wooden bolts or treenails, so that, with a few strokes of a hammer or hatchet, the planks could be cast loose and removed, and all passage along the bridge effectually cut off. The German end of the bridge was also guarded by works to prevent the French from penetrating by that communication. This is the bridge of Kehl, cele- brated in every history of hostilities between France and Germany. Various arc the methods employed in the construc- tion of wooden bridges, governed principally by the extent of water they are to cross. Even in the nar- rowest it is improper to trust to the resistance of beams reaching from bank to bank, for they ought to be trussed ; that is, to be supported by pieces of tim- ber reaching from each bank, near the water, obliquely towards the middle of the bridge. This contrivance will add greatly to its strength, and prevent its bend- ing under passing loads. One of the most important particulars to be con- sidered, in wooden bridges, is the seasoning of the timber. It is well known that the decay of fir timber is generally owing to the moist, sappy nature of its exterior surface. This moisture must be completely removed before any paint or priming be applied, in the view of securing it from the weather. K left in this natural state, this sap would, by the action of the wind and heat, be gradually carried off, and the fir beam become internally dry and solid ; but if the surface be covered with paint, oil, pitch, or other sub- stances of this kind, the sap is confined, and will soon corrupt the timber, which wUl give way before its time, and without any external symptom of decay. In order to dissipate the moisture or sap of the sur- face, it is sometimes the practice to scorch the tim- bers over a fire, turning it round regularly. The heat will attract the moisture to the surface and evaporate it, and the timber will acquire a hard crust, of great service in resisting the weather. When this is done, the parts that are to be under water shotild be care- fully covered with pitch and tar, sprinkled with sand and powdered shells. Those which are in sight should, while the wood is still hot from the fire, be rubbed over with linseed oil, mLxed with a little tar, which will then strike deep into the wood, and soon become so hard as to be fit to paint. Fii' timber, thus prepared, is found to be nearly equal to oak in dura- bility. At Schaffhausen, in the north part of Swit- zerland, was once to be seen a wooden bridge over the Rhine, there very rapid, so that no stone bridge could resist it — admirable in its construction, and be- ing the production of a plain country carpenter. The builder was directed to avail himself of a part of one of the piers of the stone bridge still remaining in its place, to support the intended structure. With this order he apparently complied, but so conti'ived mat- ters that, in the opinion of the best judges, his bridge actually consisted of but one immense arch, of near four hvmdred feet, (the breadth of the river,) having a part stooping down, as it were, to rest upon the pier in the water, but not, as far as coiold be discovered, actually resting on it. With very long fir beams, prepared for the pvirpose, extended at an angle of mod- erate elevation above the horizon from both sides of the river, and in conjunction with intermediate tun- bers, meeting over the water, two arches were formed, being segments of large circles, and resembling the circular frame of the centring of a stone bridge. These arches were placed parallel to one another, INTRODUCTION. 33 at a distance sufficient for the breadtli of the road, which was formed upon timbers suspended from the arches on each side, so as to be quite horizontal from end to end ; and, instead of going over the supporting arches, was, in fact, let down between them. The whole was roofed over, and enclosed at the sides, with windows at convenient distances to defend the timber from the weather. This most ingenious and most useful piece of carpentry, which had gained the applause of all men of genius and skill, completely answered its destination from 1740, when it was constructed, to 1799, when it was destroyed by the French. IRON BRIDGES. Bridges of iron are the production of British inge- nuity exclusively. Iron being the great staple metal of the country, it has of late been employed in many works where great strength is required in proportion t6 the weight of the materials. Melted or cast iron possesses several advantages over stone or wood ; and these, in their turn, possess advantages over cast iron. To stone, iron is superior in tenacity and elasticity, and thence in strength, in facility of formation in any desired shape, and in extent of the masses in which it may be formed — qualities all conducing to its superior lightness and cheapness. To wood, iron is superior in the same particulars, together with dura- bility ; but in this last respect, stone has greatly the advantage over iroii equally exposed to the weather or other natural agents. The greater durability of stone arises from its being less liable to decomposi- tion from the atmosphere, and from its being less elastic, and consequently less subject to friction among its component particles, in yielding to the load and motion of carriages passing over it. Several ways may, however, be adopted to remedy, in a great de- gree, these defects of iron. Paint will prevent it from oxidation, or rusting, for many years, and the appli- cation may, when necessary, be repeated without much expense. Cast-iron carriages of garrison guns have, by various external applications, been perfectly preserved for upwards of a century. The vibratory motion of an iron bridge may also be considerably diminished by the manner of placing and connecting the bars of which it consists, so that each bar shall act as nearly as possible at right angles against another, and be at the same time so short as not to be in danger of being bent or crushed by the pressure against its length. The greatest objection in this respect to cast iron is this — that, on account of the imperceptible differences in the purityand other qual- ities of the metal, it is impossible to cast two bars or blocks even in the same mould, which shall shrink perfectly and equally in cooling, and, consequently, be of precisely the same dimensions when employed in the work. When such pieces come to be joined to- gether, therefore, some empty space must necessarily exist among them, which in a large work, where uianv pieces are employed, must produce a very sensible play in the joinings, and, consequently, great vibration or reciprocal motion in the whole structure. This inaccuracy of the joinings may, it is true, be in some measure corrected, by inserting pieces of sheet lead in the joinings; but this metal possesses by far too little cohesion of parts, and too little elasticity, to be of use for any length of time. In order to prevent the evils arising from these defects of cast iron, it has been proposed to fill up the vacant spaces left be- tween the iron framing with some compact, cheaj) materials, such as brick united with the composition called Roman or Parke's cement, or Pozzolano, or terras, which would readily and intimately combine with the iron, thus defending it from the action of the atmosphere. The interstices between the bars being thus also filled up by a consolidated substance, the play, friction, and vibratory motion of the bridge would be greatly diminished. Lightness being, how- ever, a most desirable property, it has also been pro- posed to form hollow bricks solely for this purpose, which, being carefully and thoroughly baked, or even semi-vitrified on the surface, would be proof against the effects of the atmosphere. In many parts, bricks are still seen in remains of Roman buildings, fifteen or sixteen hundred years old in perfect preservation, while the stones, with which the bricks are buOt up in alternate layers, are often greatly decayed, unless when enveloped in the admirably-constituted mortar of those days. Iron may be used for bridges, either on the principle of equilibration, as stone is employed, or on that of connection by framing, as wood is some- times employed in bridges, but generally in roofing houses. For bridges of considerable dimensions the former is, by many judges, esteemed the best mode ; but for small bridges, the latter mode will probably be found the cheapest. As iron bars, rods, or blocks may be firmly connected together by bolts, or other means, an iron arch may be constructed much flatter ; that is, in the segment of a much greater circle than if it were of stone — an advantage of very great im- portance in certain positions, where arches of great span are required. The first iron bridge of any note constructed in England was that of Colebrookdale, in Shropshire. It consists of five ribs, each of three concentric arches, bound together by pieces in the direction of radii of the circle. The interior arch forms a semicircle, but the others reach only to sills under the road way. These arcs pass through an up- right frame of iron at each end, serving as a guide ; and the small space in the haunches, between the frames and outer arc, is filled up with a large iron ring. On the ribs are laid cast-iron plates, to support the road. The span, or opening of the arch, is 100 feet 6 inches, and the height from the base line to the centre is 40 feet. The road along the bridge is 24 34 INTRODUCTION. feet broad, formed on a bed of clay and iron slag, (the refuse from the furnace where iron ore is smelted,) a foot in depth. Another bridge of the same material was after- wards erected over the mouth of the River Were, form- ing the Harbor of Sunderland, a great coal port in the county of Durham. The peculiar construction of this bridge consisted in applying iron, or other metal- lic substance or compound, to form arches on the same principle with stone arches, by a subdivision into blocks easily portable, answering to the key- stones of a common arch, which, being made to bear on one another, will have all the firmness of a stone arch. At the same time, by the great open spaces left between the blocks and their respective lateral distances, the arch becomes materially lighter than if it were of solid stone, and, by the tenacity of the metal, the parts are so intimately connected that the delicate but indispensable calculation of the size and weight of the stones composing the arch becomes of but little importance. This bridge is in span 236 feet, and as the stones from which the arch springs on each side project 2 feet, the whole opening is 240 feet. The arch is a segment of a circle of 222 feet radius, and the height from the chord to the top of the arch is 34 feet ; but the whole height of the mid- dle of the arch above the surface of the river, at low water, is about 100 feet, so that ships can pass under it. A series of 105 blocks form one rib, and six of such ribs compose the width of the bridge. The va- cant spaces between the arch and the road are filled up by cast-iron circles, which touch the outer circum- ference of the arch, and also support the road, grad- ually diminishing from the abutments towards the centre of the bridge. Diagonal iron bars are laid on the top of the ribs, reaching to the abutments, to keep the ribs from twisting. The supersti-ucture is a strong frame of timber, planked over to support the carriage road, composed of marble, limestone, and gravel, with a cement of tar and chalk laid on the planks in order to preserve them. The whole width of the bridge is 32 feet. The abutments are masses almost of solid masonry, 24 feet in thickness, 42 in breadth at the bottom, and 37 at the top. The weight of the iron in the whole work is 260 tons, of which 214 are cast, and 42 wrought iron. The expense of the whole, forty years ago, was £27,000, or $119,880. The Waterloo Bridge, over the Thames, will be illustrated by a plate for that purpose. BRIDGES IN BOSTON. Some of the most striking objects which attract the notice of strangers on visiting Boston, Massachu- setts, are the bridges which lead from its various points. Although wc cannot boast of so grand su- perstructures as the ancient city of London, we, nev- ertheless, have a greater number of those convenient avenues. The Western Avenue is a splendid mill dam, built of solid materials. Warren Bridge was built in 1828. All these bridges are well lighted by lamps when the evenings are dark ; and the lights, placed at regular distances, have a splendid and romantic appearance. WESTERN AVENUE. This splendid work was projected by Mr. Uriah Cotting, who, with others associated, received an act of incorporation, June, 1814, under the title of " The Boston and Roxbury Mill Corporation." It was com- menced in 1818, under Mr. Cotting's direction, but he did not live to witness its completion. His place was supplied by Colonel Loammi Baldwin, and the road was opened for passengers July 2, 1821. This Avenue, or Mill Dam, leads from Beacon Street, in Boston, to Sewall's Point, in Brookline, and is composed of solid materials, water-tight, with a gravelled siuface, raised three or four feet above high-water mark. It is one mile and a half in length, and a part of the way 100 feet in width. The water which is admitted is ren- dered subservient and manageable. Very extensive mill privileges are gained by the aid of a cross dam, running from the principal one to a point of land in Roxbury, which divides the reservoir or full basin on the west from the running or empty basin on the east. There are five pairs of floodgates in the long dam, grooved in massy piers of hewn stone ; each pair moves from their opposite pivots towards the centre of the aperture on a horizontal platform of stone, lentil they close in an obtuse angle, on a pro- jected line cut on the platform, from the pivots in the piers to the centre of the space, with thefr angular points towards the open or iincnclosed part of the bay, to shut against the flow of tide, and prevent the passage of water into the empty basin. In this man- ner, all the water is kept out from this basin, except what is necessary to pass from the full basin through the cross dam, to keep the mill works in operation. The reservoir is kept full by means of similar flood- gates opening into the full basin, (when the rising of the tide gets ascendency over the water in the reservoir,) and fills at every flow, and closes again on the receding of the tide. In this way, at every high tide, the reservoir is filled, and a continual supply of water is made to pass through the sluice ways in the cross dam, sufficient to keep in motion, at all times, at least one hundred mills or factories. At low water, the floodgates of the receiving basin open and discharge the water received from the reservoir. WARREN BRIDGE. The construction of this bridge was commenced in June, 1828, and was completed in November follow- ing, under the superintendence of Joshua Burr, Esq., INTRODUCTION. of Cliurlestown, Massachusotts. It is one of the most pertect works of its kind in the Commonwealth. It is certainly not exceeded by any other in point of dura- bility and ease of travel. It opens on the Charles- town side, about ten rods above (west) Charles River Bridge, and, running in a southerly direction, termi- nates on the westerly part of the Will Pond Land, so called, in Boston, just east of the Middlesex Canal. It is the most direct, and the shortest, communication between Boston and Charlestown. The bridge is supported by 75 piers, placed at equal distances of 18 feet. It is 1390 feet in length, and 44 in width, allowing 30 feet for the carriage way, and 6^ on either side, handsomely railed, for foot passengers. The floor of tlie bridge is composed of hewn hemlock timber, about 14 inches deep, the apertm-es between which arc well chinked with small pieces of stone, the whole covered with 6 inches of tempered clay. On this is spread 8 inches of coarse gravel, covered with 8 inches of macadamized stone. The sides of the carriage way are secured by edge stones, 12 inches deep and 9 thick. The floor tim- bers are placed lower than those of other bridges, in order that they may be occasionally wet by the high tides, which, it is thought, will tend to their preser- vation. That teams pass over this bridge with great ease is sufficiently demonstrated by the fact that a single yoke of oxen has been known to convey 161 tons at one time, from the draw into Charlestown, without any unusual effort. The draw, in the centre of the bridge, is of suffi- cient width to admit vessels of three hundred tons. It has wharves on each side, built on piers which are planked from the capsill to low-water mark, for the more safe and easy passage of vessels. Its con- veniences, in this particular, are in strict agreement with the general excellence of the whole structure.* * This bridge ■was considered, at the time it was built, to be a yery durable and scientific structure ; but, in 1S40, it was found to be in so decayed a state that imnacdiato repairs were necessary to render it in any degree safe for travel ; a thorough examination was made, -which resulted in a recommendation to remove the clay and stones referred to, and make such other alterations as the case might demand. In the Bay State Democrat of October 8, 1842, we find the fol- lowing description of the repairs made at that time : — " Warren Bridge has recently been thoroughly repaired in all its parts. All the old timbers have been removed, and new materials substituted. This -work has been done under the direct superin- tendence of Ebenezer Barker, Esq., the agent of Warren Bridge, ■who has completed it in a manner highly creditable to himself, and ■worthy of the magnitude of the enterprise. It is a fine specimen of mechanical skQl, is somewhat novel in its style of execution, and may be looked upon as one of the greatest ■works of its kind in the country. We have thought that some statistics in connection ■with this subject ■would not prove uninteresting to the general reader. " Warren Bridge ■was incorporated March 12, 1828, and opened in the subsequent December. It is now 1388 feet in length, of which 1318 feet are covered by hexagonal blocks of white pine. Its whole width is 44 feet — the travel way being 30 feet, and the side walks occupying 7 feet each. To begin at the foundation of the work, and for the purpose of giving the pubUc accurate information TOWN'S IMPROVED BRIDGES. A minute and accurate description of Town's i.n- provement in the construction of wooden and iron bridges is given in a succeeding part of this work. We commend the article to the learner, as being par- ticularly worthy of his serious and attentive consid- eration. WHITE'S TUBULAR SUSPENSION BRIDGE. [Patent Right secured.] Ammi White, Esq., of Boston, has a model of a bridge, which supersedes the necessity of piers in crossing our largest rivers. He asserts that it can with safety be extended, even for railroad purposes, fifteen hundred feet. The mode of its construction is as follows : — " First, erect the towers on good and firm abut- ments, or on a rocky bank ; then extend across the stream two or more sets of stringers, according to the number of road beds needed. The number of string- ers in each set will depend upon the amount of strength required in the bridge. Each stringer is made by selecting a tree of proper size, which is sawed square, and is tapered from the top to within about five feet of the base. This serves as a start- ing-point, on which are spliced good sound boards, six or seven inches in width, on a curve of forty feet in five hundred, till the required length and thickness is obtained, the whole terminating in a corresponding timber which forms the other extremity. Li securing one board upon another, care is taken to fix keys of wood or iron into mortises made half into one board, and half into the other, to prevent the stringer from elongating, which, with the additional bolts placed near the dowels, is as incapable of divulsion as the of its whole construction, we wiU say, first, that on the heads of the pUes white pine caps, 14 inches square, are placed ; on these caps rest stringers 6 by 14 inches, of the same material, in a longitudinal direction, being on the outside 12 inches deep ; thus making in the centre a crown of two inches elevation. On these stringers, trans- versely or at right angles, rest yellow N. C. pine ribbons, or laths. 4 by 5 inches, and spiked to every other stringer by 8 uich spikes. Upon the end of these ribbons, and over the outside stringer of the road way, white pine edge timber, 10 by Oj inches, is laid so as to project 2 inches each way beyond the stringer beneath it. This tim- ber is bolted to the stringers once in every 4 feet, to secure more firmly the ends of the ribbons in then- places ; and on the under side of these timbers, and about one inch from each edge, grooves of half an inch deep and wide are made. " On such a foundation as this, the white pine blocks — which, by the way, are of Maine pine, and have been alluded to — are laid. As a matter of experiment, blocks of 10 and 11 inches size are put down on the Boston side, and of 12 inch size on the Charlestown side. These blocks are all tongued and grooved, or matched, which serves to secure the ■(vhole firmly together, and to present an even and uniform surface. On the surface of these blocks is put a liquid preparation — first, a coat of turpentine mLxed with oil, then a coat of tar and pitch poured on very hot. To this is added a coat of gravel, rolled in by a machine, so as to fill the interstices and pores of the blocks. The object of all this care is to preserve the material 36 INTRODUCTION. tree itself. This suspension cliain or stringer is run across the stream by means of a wire cable and pul- leys, and when locked and keyed fast in the towers, with the two backstays, is allowed to take a catenary curve. After a sufficient number has been extended across, the suspension rods are bolted to them and to the girders, which arc made slightly arching, and to the floor joist. The rafter is connected with the stringer and top of the suspension rod, to which is bolted the roof, constructed of double diagonal hoarding. The floor, if a turnpike bridge, made of double diagonal planking, bolted together, is then laid, and, in the capacity of cross bracing, serves to render firm the whole structure. If a railroad bridge, the cross bracing is fitted under the floor joist, in con- nection with the girders. By loading either kind of bridge with double the weight it is required to sus- tain, the girders will be brought down to a level, and, while the weight is on, the sides are covered with a double-diagonal boarding, similar to that of the roof, both of which must be firmly attached to the towers and backstays to form a part of the strength of the of the bridge, to make it water-tight, and to prevent horses from slipping in travelling. " We would say here, that about 40 feet of the bridge, and in differ- ent sections of the same, are laid blocks of chestnut wood, from New Hampshire. " Under the sidewalks, the outside stringer is 12 inches wide, and the inside 6 by 12. On these are placed floor joists, 3 by 5 inches, covered by two inch plank. The railing is handsome and perma- nent ; and near the draw is a wooden covering, with a 25 feet roof, for the convenience of pedestrians in inclement weather. The num- ber of lamps and lamp posts arc 22. The form of the bridge is a regular ascending plain, rising from the respective abutments to the draw, about 4 inches to every 100 feet." The structure remained in the form in which it was thus repaired until 1846, when it was found that the blocks -with which the sur- face was covered had decayed so much that it was necessary to remove them, and it was at length decided to cover the southern pine timbers, before referred to, with common two inch pine planks, and these again in the same manner. This is the form in which the surface is now covered, and it is, without doubt, the best method which has been made use of since the bridge was first built. How long the blocks would have lasted under an ordinary amount of travel, we are not prepared to state ; but it was foimd that the blocks at the outer edge of the bridge were in a tolerable state of preservation, while those in the centre were in a very decayed state. It may be well here to state, in order to give the reader some idea of the trave over this bridge, that from an account kept by order of Marshal Tukey, on Saturday, October 6, 1851, from half bridge. The direct arches are formed by bolting to- gether planks on the right curve. One springs from the abutment, and connects with the stringer at the top of the suspension rod ; the other starts from the same point, and connects with the other girder, both connecting in their course with the suspension rods. The side guards, or braces, are formed by fitting a fender rave to the floor joist, which extends over the girder several feet, according to the length of the bridge. Short rafters connect with the fender rave and the suspension rod. These, together with the projecting floor joists, are covered with double diag- onal boarding. These braces prevent the bridge from vibrating. The backstays connected with the studs inserted in the sills of the towers extend back on shore the required distance, and are firmly at- tached to stone posts, deeply set in the ground at the extremity of the sills." [As regards the strength, economy, durability, and safety of this bridge, we feel warranted in saying it excels that of a great majority of bridges. — Editors.] past six, A. M., until half past seven, P. M., as published in the Com- monwealth newspaper at the time, was 3158 vehicles, 6223 passen- gers in the same, and 6095 passengers on foot. In consideration of this immense amount of travel, and also that the principal part of the vehicles consist of heavily-ladcd trucks and large freight wag- ons, it is a matter of astonishment that the blocks lasted as long as they did ; for, as may be supposed, hollows and channels were soon formed in them, and the water standing in the same caused a con- stant decay. In reference to this kind of paving, we would state, for the benefit of our readers, that it has been thoroughly tested in the streets of Boston, in some eases using hemlock, and in some others spruce but the same result as that with the pine on the bridge has followed and that now rough granite blocks, twelve inches square, are found to be the most serviceable as well as economical. We ought perhaps to state in regard to the last repairs on Warren Bridge that, at the Boston end about the Fitchburg Depot, the timbers were lowered and covered with mud from the dock for about two feet deep, and upon this, in the centre of the bridge, as far as the draw, is placed granite blocks, as above described, and that the sidewalks for the same distance are paved with bricks. This method seems to work well, as yet, and it has been so highly approved that a new bridge which is now being erected on a new road leading from the Mill Dam Avenue to Brookline is constructed for the entire length in the same manner. To our respected friend, Ebenezer Barker, Esq., who is superin- tending the new bridge, we tender our acknowledgments for his gentlemanly and kind assistance in procuring the facts relative to this importimt structure — the Warren Bridge. — Editors. ill vV H M H //r.rifr/^i// . f'r/rlf/f>» . CIVIL ARCHITECTURE. PRACTICAL QEOMETEY, The System of Geometry here introduced is as concise and sim- ple as is compatible with a proper understanding of this interesting branch of mechanical science. Descriptive Geometry is employed to communicate a knowledge of different objects. It furnishes the means of constructing ge- ographical charts, plans of buildings and machines, architectural designs, sun dials, &c. It is used, likewise, to describe the forms and relative positions of objects. By it, stone cutters, carpenters, shipbuilders, &c., find the dimensions of the works which they ex- ecute, inasmuch as these dimensions admit of a rigorous definition. That a knowledge of Geometry is essential to the greater part of our practical mechanics, does not admit of a doubt ; yet they have too generally regarded the subject with a degree of indifference, as though the ends proposed to be accomplished by it could be as accurately, and much more easily, attained by other means. This erroneous notion, however, is fast giving way to the force of truth and demonstration ; and perhaps more attention is paid to the sub- ject at the present time, by operative mechanics, than at any pre- vious period since the discovery of the science. Many attempts have been made to simplify the study, and to render the acquisition of it more easy to the learner. In many instances, these attempts have been partially successful ; but the student will bear in mind the memorable reply of Euclid — " Tliere is no royal road to geom- etry." There is no turnpike, though there are some cross roads ; but we doubt not that he who travels the old road, which has been so often proved to be good, and over which so many have travelled before him, will be as well pleased with his journey when it is accomplished as he who arrives at the end by a shorter route. It has been said, but we trust with more severity than truth, that the generality of mechanics are displeased at the sight of a geometrical theorem. If so, a very little attention to the subject will satisfy them that no study can be better calculated to awaken the dormant faculties of the mind and to force them into action. DEFINITIONS. Plate 1. 1. Geometry is that science which treats of the descriptions and properties of magnitudes in general. 2. A point has neither parts nor magnitude, as A. 3. A line is length, without breadth or thickness, asB. 4. Superficies has length and breadth only. 5. A solid is a figure of three dimensions, having length, breadth, and thickness. Hence, surfaces are the extremities of solids, and lines the extremities of surfaces, and points the extremities of Unes. 6. Lines are either right, curved, or mixed, as E. 7. A right or straight line lies in the same direc- tion between its extremities, and is the shortest dis- tance between two points. 8. A curve continually changes its directions be- tween its extreme points, as F. 9. Lines are either parallel, oblique, perpendicular, or tangential. 10. Parallel lines are always at the same distance, and will never meet, though ever so far produced, as C and D. 11. Oblique right lines in the same plane change their distance, and would meet, if produced, as I. 12. One line is perpendicular to another when it inclines no more to one side than another, as H. 13. One line is tangent to another when it touches it without cutting, when both are produced, as G. 14. An angle is the inclination of two lines to- wards one another, meeting in a point, as J. 15. Angles are either right, acute, or oblique, as K. 16. A right angle is that which is made by one line perpendicular to another, or when the angles on each side are equal, as M. 17. An acute angle is less than a right angle, as N,2. 18. An obtuse angle is greater than a right angle, as N. 38 PRACTICAL GEOMETRY. 19. Superficies are either plane or curved. 20. A plane, or plane surface, is that to which a right line will every way coincide ; but if not, it is curved. 21. Plane figures are bounded either by right lines or curves. 22. Plane figures, bounded by right lines, haije names according to the number of their sides or angles, for they have as many sides as angles. The least number is three. 23. An equilateral triangle is that whose three sides are equal, as O. 24. An isosceles triangle has only two sides equal, as P. 25. A scalene triangle has all its sides unequal, as Qor U. 26. A right angled triangle has one right angle, as R. 27. Other triangles are oblique angled, and are either obtuse or acute. 28. An acute angled triangle has all its angles acute, as S or T. 29. An obtuse angled triangle has one obtuse angle, as U. 30. A figure of four sides and angles is called a quadrangle, or quadrilateral, as V, W, X, Y, Z, &. 31. A. parallelogram is a quadi'Uateral, which has both pairs of its opposite sides parallel, as V, W, X, Y, and takes the following particular names : — 32. A rectangle is a parallelogram, having all its mgles right ones, as V and W. 33. A square is an equilateral rectangle, having all its sides equal, and aU its angles right ones, as W. 34. A rhombus is an equilateral parallelogram, whose angles are oblique, as X. 35. A rhomboid is an oblique-angled parallelogram, as Y 36. A trapezium is a quadrilateral, which has neither pair of its sides parallel, as Z. 37. A trapezoid has only one pair of its opposite sides parallel, as &. 38. Plane figures having more than four sides are, in general, called polygons, and receive other partic- ular names, according to the number of their sides or angles. 39. A. pentagon is a polygon of five sides. A hex- agon has six sides, a heptagon seven, an octagon eight, a nonagon nine, a decagon ten, an undecagon eleven, and a dodecagon twelve sides. 40. A regular polygon has all its sides and angles equal ; and if they are not equal, the polygon is irregular. 41. Aji equilateral triangle is also a regular figure of three sides, and a square is one of four — the former being called a trigon, and the latter a tetra- gon. Plate 2. 42. A circle is a plane figure bounded by a curve line, called the circumference, which is every where equidistant from a certain point within, called its centre. 43. The radius of a circle is a right line drawn from the centre to the circumference, a b, at A. 44. A diameter of a circle is a right line drawn through the centre, terminating on both sides of the circumference, as c d, at B. 45. An arc of a circle is any part of the circum- ference, 46. A chord is a right line joining the extremities of an arc, as a b, at C. 47. A segment is any part of a circle bounded by an arc and its chord, as D. 48. A semicircle is half the circle, or a segment cut off by the diameter, as E. 49. A sector is any part of a circle bounded by an arc and two radii, drawn to its extremities, as F. 50. A quadrant, or quarter of a circle, is a sector, having a quarter of the circumference for its arc, and the two radii are perpendicular to each other, as G. 51. The height or altitude of any figure is a per- pendicular let fall from an angle, or its vertex, to the opposite side, called the base, as a b, at H. 52. When an angle is denoted by three letters, the middle one is the place of the angle, and the other two denote the sides containing that angle. Thus : let a & c be the angle at I, then b will be the angular point, and a b and b c will be the two sides contain- ing that angle. 53. The measure of any right-lined angle is an arc of any circle contained between the two lines which form the angle, the angular point being in the centre, as K. Thus, if the arc b c d he double of the arc b c, then the angle bad will be double that of b a c. -i. \ .0 /' l'K<)JJJ,r-M s II. /■ ?}yf. 1 . . // '■■ < HI. '/ 1) .V ■-■..„. li PRACTICAL GEOMETRY. 39 PROBLEMS. Plate 3. PROBLEM :. To bisect a given line, A B. 1. From the points A and B, as centres, with any distance greater than half A B, describe arcs cutting each other in c and d. 2. Draw the line c d, and the point E, where it cuts A B, will be the middle of the line required. PEOBLEM II. From a given point, C, in a given right line, A B, to erect a perpendicular. Fig. 1. Wlien the point is near the middle of the line. 1. On each side of the point C take any two equal distances, C d and C e. 2. From d and e, with any radius greater than C d, or C e, describe two arcs cutting each other in /. 3. Through the points/ C , draw the line/ C, and it will be the perpendicular required. Fig. 2. When the point is at, or near, the end of the line. 1. Take any point d above the line, and with the radius or distance, d C, describe the arc e C/, cutting A B in e and C. 2. Through the centre d in the point e, draw the line e df, cutting the arc e Cf, inf. 3. Through the points / C draw the line / C, and it will be the perpendicular required. PROBLEM III. From a given point, C, out of a given right line, A B, to let fall a perpendicular. 1. From the point C, with any radius, describe the arc d e, cutting A B in e and d. 2. From the points e d with the same, or any other radius, describe two arcs cutting each other in /. 3. Through the pomts C / di-aw the line CD/, and C D will be the perpendicular required. PROBLEM IV. A t a given point, D, upon the right line, D E, to make an angle equal to a given angle, a B J. 1. From the point B, with any radius, describe the arc a b, cutting the legs B a, B 6, in the points a and b. 2. Draw the line D e, and from the point D, with the same radius as before, describe the arc ef, cutting DEin e. 3. Take the distance b a, and apply it to the arc ef, from e to/. 4. Through the points D/draw the line D/, and the angle e D/will be equal to the angle 6 B a, as was required. PROBLEM V. To divide a given angle, ABC, into two equal angles. 1. From the point B, with any radius, describe the arc A C. 2. From A and C, with the same or any other ra- dius, describe arcs cutting each other in d. 3. Draw the line B d, and it will bisect the angle A B C, as was required. PROBLEM VI. To trisect or divide a right angle, ABC, into three equal angles. 1. From the point B, with any radius B A, describe the arc A C, cutting the legs B A and B C, in A and C. 2. From the point A and C, with the radius A B, or B C, cross the arc A C, in (? and e. 3. Through the points e d draw the lines B e, B rf, and they will trisect the angle, as was required. PROBLEM VII. Through a given point, C, to draw a line par- allel to a given line, A B. 1. Take any point rf, in A B, upon d and C, with the distance C d, describe two arcs, e C and d f, cut- ting the line A B, in e and d. 2. Make d f equal to e C ; through C and / draw C/, which will be the line required. Fig. 2. Wlien the parallel is to be at a given distance, C D from A B. 1. From any two points c and d, in the line A B, with a radius equal to C D, describe the arcs e and/. 2. Draw the line C B, to touch those arcs without cutting them, and it will be parallel to A B, as was required. 40 PRACTICAL GEOMETRY. PROBLEM VUI. To divide a given line, A B, into any proposed number of equal parts. 1. From A, one end of the line, draw A c, making any angle with A B ; and from B, the other end, draw B d, making the angle AB d equal to B A c. 2. In each of the lines A c, and B d, beginning at A and B, set off as many equal parts, of any length, as A B is to be divided into. 3. Join the points A 5, 1 4, 2 3, &c., and A B will be divided as was required. PROBLEM IX. To find the centre of a given circle, or one al- ready described. 1. Draw any chord A B, and bisect it with the perpendicular C D. 2. Bisect C D with the diameter E /, and the inter- section O will be the centre required. PROBLEM X. To draw a tangent to a given cii-cle, that shall pass through a given point, A. 1. From the centre O, draw the radius O A. 2. Tluough the point A draw D E perpendicular to O A, and it will be the tangent required. PROBLEM XI. To draw a tangent to a circle, or any segment of a circle, ABC, through a given point, B, without making use of the centre of the circle. 1. Take any two equal divisions upon the circle ; from the given point B, towards d and e, draw the chord e B. 2. Upon B, as a centre, with the distance B d, de- scribe the arc fd g, cutting the chord e B, in/. 3. Make d g equal to df, through g draw g B, and it wU". be the tangent required. PROBLEM XII. A circle, A B C, being given, and a tangent, D H, to that circle, to find the point of contact. 1. Take any point e, in the tangent D H ; from e, to the centre of the circle G, draw e G. 2. Bisect e G, in/, and with the radius /e, or/ G, describe the semicircle e C G, cutting the tangent and the circle in C ; it will be the point required. PROBLEM XIII. Given three points, ABC, not in a straight line, to find a number of points Ipng between them, so that they shaU aU be in the circum- ference of a circle, without drawing any part of the circle, or finding the centre. 1. From A, through B and C, draw A B and A /. 2. On A, as a centre, with any radius A/, describe an arc/e d, cutting A B in ;/.•/. I'l 7 TKOn. XI. Xll . .\1\' JCVl PRACTICAL GEOMETRY. 41 join E F, if necessary, and draw n N, vi M, / L, &c., parallel to it, cutting the diameters N N, M M, L L, &c., at N M L, &c. ; tlicn these points will be in the periphery of the ellipsis. If the diameters arc pro- duced to the opposite sides, at N M L, and the dis- tances E N, E M, E L, &c., are made respectively to their corresponding opposite distances, E N, E M, and E L, &e., then the points N M L, on the under 5ide of the diameter A B, will also be in the curve. PEOBLEM IX. To draw an ellipsis by ordinates, having the axes, or any other conjugate diameters, A B, and C D, given. 1. From E, the cenh-e, cb-aw E F perpendicular to C D. Upon E, with the radius E C, describe the quadrant C F ; divide E F into any number of equal parts, as four ; from these points draw 1 a, 2 b, 3 c, parallel to E C, cutting the quadi-ant at a, b, and c. 2. Divide E A and E B each in the same number of equal parts ; through the points 1, 2, 3, &c., draw a a, b b, c c, &c., parallel to C D. 3. Make the distances 1 a, 2 b,3 c, See, equal to then- coiTcsponding distances, 1 a, 2 b, on the quad- rant ; then the points a, b, c, &c., will be all in the periphery of the ellipsis. PROBLEM X. An ellipsis, A B C D, being given, to find the transverse and conjugate axes. 1. Draw any two parallel lines A B, and C D, cut- ting the ellipsis at the points A, B, C, D ; bisect them in c and/. 2. Through e and/ draw G 11, cutting the ellipsis at G and H; bisect G H at I; it will give the centre. 3. Upon I, with any radius, describe a circle, cut- ting the ellipsis in the four points, k, I, m, n. 4. Join k I, and m n ; bisect k I, or vi n, at o or p. 5. Through the points o I, or Ip, draw Q, R, cut- ting the ellipsis at Q and R ; then Q, R will be the transverse axis. 6. Through I, draw T S parallel to k I, cutting the ellipsis at T and S, and T S will be the conjugate axis. Plate 7. PROBLEM XI. Any diameter, A B, being given, and an ordi- nate, C D, to find its conjugate, without draw- ing any part of the ellipsis. 1. Draw C I perpendicular to A B ; bisect A B in F, and draw F H parallel to C D. 2. On F, with the distance F A, or F B, describe the semicircle A I B, cutting C I at I. 3. Make A E equal to C I ; cbaw E G parallel and equal to C D ; through G and A draw A H, cutting F H at H ; then F H is the semi-conjugate. Much after the same manner, if two conjugate diameters are given, an ordinate may be found with- out drawing any part of the ellipsis. PROBLEM XII. Any two conjugate diameters, A B and C D, being given, and a right line, G H, passing through the centre, F, to find a diameter which will be conjugate to G H, without drawing any part of the ellipsis. 1. Through D draw E K parallel to A B, and pro- duce the given line H G to cut the tangent in E. 2. From D, make D I perpendicular to E F, and equal to F A, or F B. 3. Join E I; from I, di-aw I K perpendicular to I E, cutting the tangent E K at K ; through the centre F draw F K. 4. Through the points g- and m, where the lines E I and I K cut the circle, draw g- G and vi M par- allel to I F, cutting E F, and K F, at the points G and M ; make F H equal to F G, and F L equal to F M ; then M L and G H will be the two other conjugate diameters. PROBLEM XIII. Any two conjugate diameters, A B and C D, being given, to find the two axes, from thence to describe the ellipsis. 1. Through D draw E F, parallel to A B ; draw D I perpendicular to E F, and equal to M A, or M B. 2. Upon I, with the radius I D, describe the arc g- D /. 3. Join I M, and bisect it by a perpendicular, meet- ing the tangent E F at N. 4. On N, as a centre, with the distance N I, de- scribe a semicircle E I F, cutting E F at the points E and F. 48 PRACTICAL GEOMETRY. 5. Through the centre M draw F K and E H. 6. Join I E and I F, cutting the arc g- D / at g and /. 7. Draw I L and g G parallel to I M, cutting K F and H E at G and L. Make M K equal to M L, and P*I H equal to M G ; then E H and K L will be the two axes required. PROBLEM XIV. An ellipsis being given, to draw a tangent through a given point H, in the curve. 1. Find the foci F and G ; join F H and G H. 2. Produce C G H to I upon H, with any radius ; describe the arc K L I, cutting G I and F H at K and I. 3. Bisect the arc K L I at L ; through L and H draw L H ; it will be the tangent required. PROBLEM XV. To draw two tangents to an ellipsis from a given point, E, without it having any two conjugate diameters, A B and C D, given, without drawing any part of the ellipsis. 1. Let the point E be in the diameter D C, pro- duced. 2. From the centre H make H I equal to H C, and join I E. 3. Through C draw C K parallel to I E, cutting H A in K. 4. Make H L equal to H K ; through L chraw F G parallel to A B ; find the extreme points F and G of the ordinate F G by Problem XI. From E, through the points F and G, draw E F and E G. They will be the tangents required. If the point E is in neither of the given diameters A B or C D, when produced, draw a line from the given point E, through the centre ; by Problem XII., find a conjugate to that Line, and the extremities of both ; then the construction will be the same as in this. PROBLEM XVL To describe an ellipsis similar to a given one, A D B C, to any given length, I K, or to a given width, M L. 1. Let A B and C D be the two axes of the given ellipsis. 2. Through the points of contact, A, D, B, C, complete the rectangle G E H F ; draw the diag- onals E F and G H. They will pass through the centre at R. 3. Through I and K draw P N and O Q parallel to C D, cutting the diagonals E F and G II at P, N, Q, O. 4. Join P O and N Q, cutting C D at L and M ; then I K is the transverse, M L the conjugate axis of an ellipsis that will be similar to the given one, A D B C, which may be described by some of the foregoing methods. Plate 8. PROBLEM XVII. Given the rectangle A B C D, to circumscribe an ellipsis which shall have its two axes in the same ratio as the sides of the rectangle. 1. Draw the diagonals A C and B D, cutting each other at S, the centre. 2. Through S draw E F and G H parallel to A B and A D. 3. Upon S, with a radius, S I, equal to half A D or B C, describe the quadrant I K L cutting E F at L. 4. Bisect the arc I K L at K ; through K draw M N parallel to E F, cutting the diagonal B D at N. 5. Join I N ; through B draw B G parallel to it, cutting G H at G, and make S H equal to S G. 6. Join N O ; through B draw B F parallel to it, cutting E F at F ; make S E equal to S F ; then E F and G H are the two axes which may be de- scribed by some of the methods which are shown in the foregoing problems. PROBLEM XVIII. Given the trapezium, A B C D, and a point E, in one of the sides, to find a point in each of the other sides, so that, if an ellipsis was to be inscribed, it Avould touch the trapezium in these points. 1. Produce the sides of the trapezium till they meet at K and L. 2. Draw the diagonals A C and B D, cutting each other at F ; produce B D till it cut K L at M. 3. Through F, and the given point E, draw E G, cutting B C at G. I'l '! I'liOl'. . X\'l\ c. XX'lil. XIX \X 1 I 'I |)rl!llllliiiis. Ill' llll' I'.i 1 .ilxil.i ruoi'. . 1 . V 11 ^v I 1' !•: f. V. •■ ii /■W/. ?. / or 111,- iiv|M-ii PRACTICAL GEOMETRY. 49 4. From M, through the points E and G, draw M H and M G, cutting the other two sides in the points I and H, then E, H, G, I, will be the four points requii'cd. PROBLEM XIX. A trapezium, A B C D, being given, and a point E, in one of the sides, to find the centre of an ellipsis that may be described in the trape- zium, and pass through the point of contact E, without dramng any part of the ellipsis. 1. Find the points of contact H, G, I, E, as in the last problem. 2. Join the points G and E by the right line G E, bisect it in M, and from K, where the opposite sides A D and B C meet, and through the point M, draw K M indefinitely. 3. Also join any other t\.vo points of contact, as H I ; bisect H I at N, from L, where the opposite sides B A and C D meet ; di-aw L N, meeting K M at P ; then P will be the centi'c of the ellipsis re- quired. And, in lilce manner, if the points G and H were joined and bisected at Q, and a line being drawn from B where the opposite sides A B and C D meet through Q, it woidd also meet in P, the centre, &c. PROBLEM XX. Given a trapezium, A B C D, and a point E, in one of the sides, to find the two axes of an ellipsis that may be inscribed in the trape- zium, and pass through the pomt E without drawing any part of the ellipsis. 1. Find the opposite pomts of contact, H, E, F, G, by Problem XVIII. 2. From thence, find the centre, P, by the last prob- lem. 3. From E, and through the centre, P, draw E M, making P M equal to P E. 4. Through H, or any other point of contact, draw H K parallel to D C, cutting E M at K ; then K H is an ordinate to the diameter E M. 5. Tlu-ough P, the centre, draw P E parallel to H K. 6. Find the extremities R and S, of the diameter R S, by Problem XL 7 7. The conjugate diameters E M and R S, being now found, then find the two axes, V W and X Y, by Problem XIII. PROBLEM XXI. To find the centre and transverse axis of an ellipsis by means of a square and rule. 1. Apply the square A B, Problem XXI. 2. Place the ellipsis tangical to A B, at pleasure, 3. Draw lines C D, touching the opposite sides of the ellipsis. 4. Draw lines E F, intersecting the ellipsis ; and C is the centre, and E F the transverse axis required. Also, E F is equal, added together, in whatever direction the ellipsis may be appHed to the square and rule. OF THE PARABOLA. DEFINITIONS. Plate 9. 1. If a thread, equal in length to B C be fixed at C, the end of a square, ABC, and the other end fixed at F ; and if the side A B, of the square, be moved along the right line, A D; and if the point E be always kept close to the edge B C, of the square, keeping the string tight, the point or pm E will de- scribe a curve E G I H, called a parabola. 2. Focus is the fixed point F, about which the string revolves. 3. Directrix is the line A D, which the side of the square moves along. 4. Axis is the line L K, drawn tlu-ough the focus F, perpendicular to the directi-is. 5. Vertex is the point I, where the line L K cuts the curve. 6. Latus rectum, or parameter, is the line G H, passing through the focus F, at right angles to the axis I K, and terminated by the curve. 7. Diameter is any line M N, drawn parallel to the axis I K. 8. Double ordinate is a right line R S, drawn par- allel to a tangent at M, the exti-eme of the diameter M N, terminated by the curve. 9. Abscissa is that part of a diameter contained between the curve and its ordinate, as M N. 6( PRACTICAL GEOMETRY. PROBLEMS. PROBLEM I. To describe a parabola by finding points in the curve, tlic axis A B, or any diameter be- ing given, and a double ordinate C D. 1. Through A draw E F parallel to C D. 2. Through C and D, di-aw D F and C E parallel to A B, cutting E F at E and F. 3. Divide B C and B D each into any number of equal parts, as four. 4. Likewise divide C E and D F into the same number of equal parts, viz., four. 5. Through the points 1, 2, 3, &c., in C D, draw the lines 1 a,2b,S c, &c., parallel to C D. 6. Also through the points 1, 2, 3, in C E and D F, draw the lines 1 A, 2 A, 3 A, cutting the parallel lines at the points a, b, c, then the points a, b, c are in the curve of the parabola. Fig. 2. Another method. 1. Join A C and A D ; from A make A E equal to B C or B D. 2. Through A and E, draw H I and F G parallel to C D, cutting A C and A D in the points F and G. 3. Through F and G, di-aw F H and G I parallel to A B, cutting H I at the points H and L 4. From the points H and I, take any number of equal divisions on the lines H F and I G ; from these points draw lines to A. 5. From B, set the same divisions towards C and D ; draw the parallel lines 1 a, 2 6, 3 c, &c., intersect- ing the former at the points a, b, c ; they will be in the curve of the parabola. OF THE HYPERBOLA. DEFINITIONS. 1. If B and Care two fixed points, and a rule A B be made movable about the point B, a string ADC, being tied to the other end of the rule, and to the point C, and if the point A is moved round the cen- tre B, towards E, the angle D, of the string ADC, by keeping it always tight and close to the edge of the rule, A B, will describe a curve, D F H G, called an hyperbola. 2. If the end of the rule at B was made movable about the point C, the string being tied from the end of the rule A to B, and a cui-ve being described after the same manner, it would be an opposite hyperbola. 3. Foci are the two points B and C, about which the rule and string revolve. 4. Transverse axis is the line I II, terminated by the two curves passing through the foci, if continued. 5. Centre is the point M, in the middle of the transverse axis I H. 6. Conjugate axis is the line N O, passing through the centre M, and terminated by a circle from H, whose radius is M C, at N and O. 7. Diameter is any line V W, drawn through the centre M, and terminated by the opposite curves. 8. Conjugate diameter to another is the line drawn through the centre parallel to a tangent with either of the curves, at the extreme of the other diameter, terminated by the curves. 9. Abseissa is when any diameter is contained within the curve, terminated by a double ordinate and the cm-ve, then the part within is called the abscissa. 10. Double ordinate is a line di'awn through any diameter, parallel to its conjugate, and terminated by the cm"ve. 11. Parameter, or latus rectum, is a line di-awn through the focus, perpendicular to the transverse axis, and terminated by the curve. 12. Asymptotes are two right lines drawn from the centre M, and the points R S, which are parallel to the conjugate axis N O, and drawn through the end of the ti'ansverse axis I H; II R and H S being equal to M N or M O, then M X and M Y are asymptotes. 13. Equilateral or right-angled hyperbola is when its transverse or conjugate axes are equal. PROBLEMS. Plate lO. PROBLEM I. To describe an hj^icrbola by finding points in the curve having the diameter, or axis A B, its abscissa B C, and double ordinate D E. 1. Through B, draw G F parallel to D E ; from D and E, draAv D G and E F parallel to B C, cutting G F in F and G. ruoi". . I ir I'l A 5 I> J 2 J C 3 Z J III n^ ( .-••'" \X I'l II \'ll I'KOl'.. I a!I(S^O®!iaS ®1? 3®[Lfl®g. Ol'a CNlnnlir ::X PRACTICAL GEOMETRY. 51 2. Divide C D and C E each into any number of equal parts, as four ; through the points of division, 1, 2, 3, draw lines to A. 3. Likewise divide D G and E F into the same number of equal parts, viz., four ; from the divisions on D G and E F draw lines to B, and a curve being drawn tlirough the intersections at B a ft c E, wUl be the hyperbola required. PROBLEM 11. Given the asjinptotes A B, C D, and a point E, in the curve, to describe the hyperbola. 1. Through the given point E, di-aw any right line E F, cutting the asymptotes in the points i and I. 2. Malce i F equal to I E ; from F draw as many lines as you please, cutting the asymptotes in the points g-, h, i, k, &c., and G, H, I, K, &c. 3. Make G /, H /, K /, &c., respectively, equal to g F, h F, k F, &c., through the points/,/,/, describe a curve, and it is the hyperbola required. In the same manner may the opposite hyperbola be described. PROBLEM IIL Given the two conjugate diameters A B and C D, to find any number of j)oints in the curve. 1. Through B draw F G parallel to C D, make B F and B G equal to E C, or E D ftom E, tlirough F and G di"aw E H, and E I, the asymptotes. 2. From A di-aw any lines A C, A D, A E, and A F, cutting the asymptotes at the points a, a, a, &c., and c, d, e, /, &c. Make the distances « C, « D, « E, a F, &c., equal to A c, A d, A e, and A/, &c., then the points C, D, E, F will be in the curve. Fig. 2. Another method. 1. From the centre E, draw E I perpendicular and equal to E A or E B. 2. Join B C, take any number of points, F, G, H, in E B, and chaw F / G g-, H h parallel to B C, cutting E C at/ g-, h. 3. Through/ g-, h, B C, di-aw/ A', g I, h m, i n, &c., take the distance F I, and make//c equal to it; then take G I, and make g I equal to it ; in the same manner, find the points m n. And if E B and E C are produced indefinitely beyond B and C, and lines be drawn parallel to B E, as before, any number of points beyond will be fomid in the same manner. PROBLEM IV. Given the asymptotes, and a point in the curve, to find two conjugate diameters. 1. From the point B, draw B H D parallel to the asymptote C G. Make H D equal to H B, draw D C E, making C E equal to C D. Make C A equal to C B, then D E is the conjugate to A B. PROBLEM V. To describe a conic section through five given points, A, B, C, D, E, provided that all these points are joined by right lines, and that any exterior or angle, formed by these lines, be less than two right angles. 1. Join any four points, A, B, C, E, forming the quadrilateral A B C E. 2. Through the fifth point D, draw D / and D g parallel to A E and B C, meeting A B, produced both ways at the points / and g-, if necessary. 3. Also, tln:ough D, draw h i parallel to E C, meetmg B C and A E, produced at the points h and i. 4. Divide D //, D i, and D/ T> g, into any number of equal parts, as sLx ; likewise divide D F and D G into the same, viz., sbc. 5. From the point b, and through the points 1, 2, 3, 4, 5, in D i, draw the lines 1 E, 2 E, 3 E, 4 E, 5 E, cutting the lines B a, B ft, B f, B d', B f, and B/ at the points a, ft, c, d, c, draw from B, through 1, 2, 3, 4, 5, in D F, which are all in the curve. In the same manner, the points between B and D wiU. be found, viz., by drawing Luies from the points A and C, through the lines D g and D h. And if the lines D i and D / are produced, and the equal parts, 7, 8, 9, extended upon these lines, you would obtain as many points, g^ h, i, &c., between A and B. Plate 11. PROBLEM VI. To describe a conic section to touch a right line A B, in a given point C, to i^ass through three other points, D, E, and F. 1. Join D C, E C, and D E ; through F draw F A and F B parallel to E C and D C, cutting A B at A and B. 2. Through F, draw G H parallel to D E, and pro- duce the sides C D and C E, to cut it at G and H. 52 PKACTICAL GEOMETRY. 3. Divide F G and F H, F A and F B, each into any number of equal parts, as four. 4. From C, through 1, 2, 3, in F H, draw Ca,Cb, C c, &c. 5. From E, through 1, 2, 3, in F H, draw 1 E, 2 E, 3 E, &c., cutting the former in the points a, b, c, which are in the curve. In the same manner may points be found in the other side. PROBLEM VII. To describe a conic section to touch two right lines, A B and B C, in the points A and C, and to pass through a given point, D. 1. Join the points A and C; through D draw D E and D F parallel to B A and B C. 2. Through D draw G H, parallel to A C, cutting B A and B C in G and H, and divide D G and D H, D E and D F, each into the same number of equal parts. 3. From A, through the points 1, 2, 3, in D E, draw the lines A c, A 6, A c. 4. From C, through the points 1, 2, 3, in D H, draw 1 C, 2 C, 3 C, cutting the former in a, h, c, which are in the curve. In the same manner may points be found between A and D. SECTIONS OF SOLIDS. OF A CYLINDER. — DEFINITIONS. 1. A cylinder is a solid, generated by the revolution of a right-angled parallelogram, or rectangle, about one of its sides ; and, consequently, the ends of the cylinder are equal circles. 2. Axis is a right line passing from the centres of the two circles which form the ends of the cylinder. 3. If a cylinder is cut by a plane, parallel to a plane passing through its axis, it will be cut in two parts, which arc called segments of the cylinder. 4. A segment of a cylinder is comprehended under three planes, and the curve surface of the cylinder ; two of these are segments of circles : the other plane is a parallelogram, which is here, for distinction's sake, called the plane of the segment, and the circu- lar segments are called the ends of the cylinder. 5. The two sides of the parallelogram, which is parallel to the axis of the cylinder, are called the sides of the segment of the cylinder, and the other two sides of the parallelogram are chords to the ends of the cylinder. 6. If a cylmder, or segment of a cylinder, stands upon one of its ends, that end on wliich it stands is called the base. 7. K the segment of a cylinder is cut obliquely by a plane, the intersection of that plane with the plane of the segment is called the chord of the section. 8. The section of a cylinder cut by any plane ui- clined to its axis is an ellipsis. This is proved by the writers of conic sections, PROBLEMS. Plate 12. PROBLEM I. To find the section of a semi-cylinder, cut by a plane at right angles to the plane A B F E, whicli passes through its axis, making a given angle E F B, vnih. either of the sides B F. 1. Let A D B be the circle of the base, and C its centre. 2. Through the centre of the circle C draw G D parallel to F B, cutting the circle of the base in D, and E F at G ; from G draw G H perpendicular to E F ; make G H equal to C D ; then E F is the transverse axis, and G H the semi-conjugate. Or it may be described by ordinates, as in Fig. 2, taken from the base and transferred to the section, as the figm*es direct. Li the same manner may any segment be found, viz., by drawing lines parallel to the sides of the plane of the segment till it cut the chords of the section ; from these points, draw perpendiculars to the chord ; make their several lengths from the chord equal to those of the base corresponding to them ; a curve line being drawn through these points, will be the true section of the segment required, as is plamly shown by Fig. 3. PROBLEM II. To find the tAVO axes of the section of a semi- cylinder cut by a plane, making a given angle A B C, with the plane E F G H, pass- 11 1. Si'l^A'S)^ I'KOIi. I _sL — q| 'V 'rj ii II . PRACTICAL GEOMETRY. 53 ing through its axis; also in a given direc- tion K I with the side K F. 1. Let E M F be the circle of the base, and L its centre. 2. From the angular point B of the given angle ABC, draw B D perpendicvdar to B A, and equal to L E or L F, the radius of the base ; di-aw D C parallel to B A, cutting B C at C. 3. Draw Q R, at the distance D C, parallel to I K ; through the centre of the circle L draw O M par- allel to K F, cutting the circle of the base at M, and I K at O ; through the point O draw O P parallel to E F, cutting Q. R at P; also through M draw M N parallel to E F, from P draw P S perpendicular to Q R, and P N parallel to O M, cutting M N at N; join L N, cutting the circle at Z; make U S equal to B C, and join O S upon O S ; from O, make O V equal to L Z, then O V is the semi- conjugate axis. 4. Through O draw W X perpendicular to O S ; draw L T perpendicular to L N, cutting the circle of the base at T ; from T, draw T Y parallel to L N, cutting the base F E, produced at Y ; from Y, draw Y a parallel to O JM, cutting K I, produced at a; from a, draw a W parallel to O S, cutting W X at W, making O X equal to O W ; then W X is the transverse axis. PROBLEM III. To find the section of a segment of a cylinder, by ordinates cut by a plane through a given line I K, in the plane of a segment, making a given angle A B C at I K, with the ^jlane E F K I. 1. Draw the tangent Z IVI parallel to E F, and draw O M parallel to K F, cutting the tangent at M, and I K at O. 2. Take the distance L M, and make B D perpen- dicular to the angular point B of the given angle ABC equal to it ; proceed as in the last problem ; Qnd O V and L Z. 3. Draw any number of lines a a, b b, c c, &c., parallel to O L, cutting the lines I K and E F at the points a, b, c, &c. 4. From the points a, b, c, &c., in I K, draw lines a 1, 5 2, c 3, &c., parallel to O V. 5. Through the points a, &, c, in E F, draw lines al,b2,c3, &c., parallel to L Z, cutting the arc line of the base at 1, 2, 3, &c. 6. Make all the distances a 1, b 2, c 3, &c., from I K, equal to all theur corresponding distances, a 1, Z> 2, c 3, &c., on the base. 7. A curve line being traced through these points, I W K will be the section required. In the same manner the section of any irregular figure may be found, as is plainly shown by Fig. 2. Fig. 3 shows how to find the section when the angle A B C is oblique. OF A CONE. DEFINITIONS. 1. A cone is a solid figure standing upon a circu- lar base, diminishing to a point at the top, called its vertex, in such a manner that, if a straight line be applied from the vertex round the circle of the base, it shall coincide every where with the curve surface of the cone. 2. A right line passing through the cone, from the vertex to the centre of the circle at the base, is called the axis. 3. If a cone be cut by a plane not parallel to its base, passing quite through the curve surface, the figure is an ellipsis. 4. If a cone be cut by a plane, parallel to a plane touching the curve surface, the section is a parabola. 5. If a cone be cut by a plane, parallel to any plane within the cone that passes through its vertex, then the figure is an hyperbola. These three last definitions are proved by the writers of conic sections. Note. — The cone in the following problem is supposed to be an upright one. PROBLEM. Plate 12. PROBLEM I. To describe the conic section from the cone. Note. — A D N is a section of the plane, passing through its axia at right angles with the sections of the ellipsis, parabola, or hyper- bola. For the Ellipsis. 1. Let G H be its transverse axis in the plane A D N ; bisect it at K ; through K draw R Q, paral- lel to A D. 54 PRACTICAL GEOMETRY. 2. Bisect Q, R at M; vnth the radius M R or M Q, describe the semicircle R P G. 3. From K, draw K H perpendicular to Q R, cut- ting the cu-cle at H; then K H is the semi-conjugate axis, from which the ellipsis may be described as at No. 1. For the Parabola. 1, Let S E be the axis of the parabola, parallel to the other side, N D. 2. From E, draw E C at right angles to A D, the base, cutting the semicu-cle at C ; then E C is an or- dinate or half the base of the parabola, which may be described at No. 2. For the Hyperbola. 1. Let I F be the height of the hyperbola ; pro- duce it till it cut the opposite side A N, produced at L ; then F L is the transverse axis. 2. From I, draw I B at right angles to A D ; then I B is half the base, which may be described as at No. 3. XoTE. — The letters arc made to eorrespond at No. 1, 2, and 3, with, those of the cone from where they are taken. OF A GLOBE. DEFINITIONS. A globe is a solid figure, and may be supposed to be generated by the revolution of a semicircle about its diameter, which becomes the axis of the globe, and the centre of the semicu-cle is the centre of the globe. Corollarij 1. Hence all right lines drawn from the centre to the circumference of a globe are equal to one another, for the semicircle touches the surface of the globe in every point as it revolves round. Corollarij 2. The section of a globe by a plane passing through its centre is a circle, whose diameter is equal to the diameter of the generating semicfrcle. Corollary 3. Every section of a globe cut by a plane is a circle, for aU the lines drawn from the cen- tre to its surface are equal ; consequently, the gen- erating semicircle may revolve round any line, as an axis ; therefore, every point in the semicircle will generate a circle. Corollary 4. If a semiglobe is cut at right angles to the plane of its base, the section is a semicircle. PROBLEMS. Plate 12. TROBLEM I. To find the section of a semiglobe at right angles to the plane A B D, thiough its cen tre, and pass through the line A B in that plane. Bisect A B in D ; on D, as a centre, ■w^th the radius D A, or D B, describe the semicircle A E B, and it will be the section required. PROBLEM II. Given two segments of cu-cles, ABC and D E F, equal or unequal, ha^dng their two chords, A C and D F, equal to each other, and the segment ABC being placed upon D F, so that A C shall coincide with D F, and the segment A B C at right angles to D E F, to find the radius of a globe, so that the arc Imcs ABC and D E F shall be in its surface when the two segments are placed in the above position. 1. Make a rectangle A D F C, so that the opposite sides, A C and D F, will be the bases of *the segments A B C and D E F. 2. Find the centres G and H of these segments. 3. Through H draw I K parallel to G F, and com- plete the semicircle I D E F K. 4. Through G or H di-aw H L parallel to G F, cutting A C and I K at L and H ; make H ]\I equal to L G, join M K or M I, and it will be the radius required. If upon E, as a centre, with the distance M I, or M K, a segment I N K is described, it will be part of the greatest circle that can be drawn in the globe. PROBLEM III. A figure being generated by the revolution of a plain figure, ha^ing two perpendicular legs, and the other side being irregular, or straight, or a curve Hue of any kind, the figure bemg made to revoh"e about one of its perpendicu- lar legs. To find the figure of the section, cut any where across the base and right an- SE©ini®RlS (j&i? 3®ILaiDS. i'l.l.t ^•\ c^-liiuLfr aTit'ilr;iiviiio':i laim'i-iil in mhIi .i rMiji'iliiiii y^ L .. L PRACTICAL GEOMETRY. 57 F A D is a right angle, the two planes are perpen- dicular. 2. (Fig. 2.) A line, A B, is perpendicular to a plane P Q, when the line A B is perpendicular to any line B C, in the plane P Q, which passes through the point B, where the line meets the plane. The point B is called the foot of the perpendicular. 3. A line A B (Fig. 8) is parallel to a plane P Q, when the line A B is parallel to another straight line C B, in the plane P Q,. 4. If a straight line have one of its intermediate points in common with a plane, the whole line will be in the plane. 5. Two planes are parallel to one another when they cannot intersect in any direction. 6. The intersections of two parallel planes with a third are parallel. Thus, in Fig. 4, the lines A B, C D, comprehended by the parallel plane P Q, R S, are parallel. 7. Any number of parallel lines, comprised be- tween two parallel planes, are equal. Thus, Fig. 5, the parallel lines A a, B b, C c, , comprised by the parallel planes P Q, R S, are all equal. 8. If two planes C D E F, G H I J, Fig. 6, are perpendicular to a third plane, P Q, their intersection, A B, will be perpendicular to the third plane P Q. 9. If two straight lines be cut by several parallel planes, these straight lines will be divided in the same proportion. GENERAL APPLICATION OF THE TRE- HEDRAL TO TANGENT PLANES. PROBLEM. Plate 14. Given the inclination and seat of the axis of an oblique cylinder or cylindroid, to find the angle which a tangent makes at any point in the circumference of the base, with the plane of the base. 1. (Figs. 1, 3, Plate 14.) Let A E B O be the base of the cylinder or cylindroid, C B the seat of the axis, and let B C D be the angle of inclination, and let O be the point where the tangent plane touches the curved surface of the solid. R 2. Draw O N a tangent line at the point O in the base, and draw O P parallel to C B. Make the angle P O R equal to B C D, and draw P R perpendicular to P O. 3. Then if the triangle P O R be conceived to be revolved round the line P O, as an axis, until its plane becomes perpendicular to the plane of llic circle A E B C, the straight line, O R, will, in this position, coincide with the cylincWcal surface, and a plane touching the cylinder or cylindroid at () will pass through the lines O N and O R. Here will now be given the two legs, P O R and P O N, of a right- angled trehedral to find the angle which the hypothe- nuse makes with the base. Draw P Q, perpendicular to O N, intersecting it in 7n, and draw P S perpen- dicular to P Q. Make P S equal to P R, and join VI S ; then P m S is the angle required. 4. The hypothenuse will be easily constructed at the same time, thus : make m Q, equal to tn S, and join O Q, then N O Q will be the hypothenuse required. 5. In Fig. 1, the method of finding the angle which the tangent plane makes with the base and the hypoth- enuse is exhibited at four different points. In the first two points, O from A, in the first quadrant, the tan- gent planes make an acute angle at each point O ; but in the second quadrant, they make an obtuse angle at each point O. 6. Fig. 2 is the second position of the construction from the point A, for finding the angle which the tangent plane makes with the base, and for finding the hypothenuse enlarged ; in order to show a more convenient method by not only requu'ing less space, but less labor, it may be thus described, the two given legs P' Q' R' and P' O' N'. 7. Draw P' m' perpendicular to O' N', meeting O N in m'. In P' O', make P' v' equal to P' m', and draw the straight line v' R', then P' v' R' will be the inclination of the tangent plane at the point O. 8. Again : in O' P' make O' t' equal to O' m', and draw i' u' parallel to P' R'. From O', with the radius O' R', describe an arc meeting i' u' in ti', and draw the straight line O' u' ; then t' O' u' is the hypothenuse. 9. For since P' S' is equal to P' R', and P' v' equal to P' ?«', and the angles m' P' S' and v' P' R' are right angles ; therefore, the triangle v' P' R' is equal to the triangle m' P' S', and the remaining angles of the one equal to the remaining angles of the other, each to each ; hence the angle P' v' R' is equal to the angle P' m' S'. 58 PRACTICAL GEOMETRY. 10. Again : because O' t' is equal to O' m', and O' Q,' is equal to O' R', and O' u' is also equal to O' R', therefore O' u' is equal to O' Q' ; and since the angles O' t' u' and O' m' Q,' are each a right angle, therefore the t\vo right-angled triangles have their hypothenuses equal to each other, and have also one leg in each equal to each other ; therefore the remaining side of the one triangle is equal to the remaining side of the other, and therefore, also, the angles which are oppo- site to the equal sides are equal; hence the angle P' O' w' is equal to N' O' Q'. 11. By considering this construction by the trans- position of the triangles, the whole of the angles which the tangent planes make at a series of points O, in figures 1 and 3, their hypothenuses may be all found in one diagram, as in Fig. 4. 12. Thus, in Fig. 4, if the angles A C O, A C O' A C O", A C O'", be respectively equal to A C O, A C O', A C O", A C O'", Fig. 1, and in Fig. 4, the semicircle A O' B be described, and if C D be drawn perpendicular to A B, and the angles CAD, C B D, be made equal to BCD, Fig. 1, then each half of Fig. 4, being constructed as in Fig. 2, the angles at m m' m" m'" will be respectively equal to the angles P m S, P' m' S', Q" m" S", Q" m'" S", in Fig. 1. Also, in Fig. 4, the angles C A E, C Ag-, C A /(, C B t, C B k, C B F will be the hypothenuses at the points A, O, O', O", 0"\ B, in Fig. 1. We may here observe. Fig. 1, that the angles which the tangent planes make with the plane of the base in the first quadrant are acute ; and those in the second quadrant arc obtuse ; and those in the second quadrant arc the supplements of the angles V m S ; and, moreover, that all the angles which constitute the hypothenuses of the trehedral are all acute, whether in the first quadrant or the second quadrant of the semicircle A O B. SECTIONS On the projection of a straight line bent vpon a cylin- dric surface, and the method of draiving a tangent to such a projection. Plate 14. PROBLEM I. Given the development of the surface of the semi-cylinder, and a straight line in the devel- opment, to find the projection of the straight line on a plane passing through the axis of the cyliuder, supposing the development to incase the semi-cylincbic surface. Fig. 5. Let A B C be the development of the cylindric surface, B C being the development of the semi-circumference, and let A C be the straight line given. Produce C B to D, making B D equal to the diam- eter of the cylinder. On B D, as a diameter, describe the semicircle BED, and divide the semicircular arc BED into any number of equal parts, at 1, 2, 3, &c., and its development B C into the same number of equal parts, at the points /, §•, h, &c. Draw the straight lines / /.-, g I, h m, &c., parallel to B A, meet- ing A C at the points k, I, m, &c. ; also parallel to B A draw the straight lines 1 o, 2 p, S q, &c., and draw ko, Ip, m q, &c., parallel to C D ; and the points o,p, q, &c., are the projections or seats of the points k, I, m, &c., in the development of the straight line A C. The projection of a screw is found by this method : B D may be considered as the diameter of the cylin- der from which the screw is formed ; and the angle B A C the inclination of the thread, with a straight line on the surface ; or B C A the inclination of the thread with the end of the cylinder. The same prin- ciple also appUes to the delineations of the hand rails of stairs, and in the construction of bevel bridges, of which we shall treat in a subsequent part of this work. PROBLEM II. Given the entire projection of a helix or screw, in the surface of a semi-cylinder, and the projection of a circle in that surface perpen- dicular to the axis, upon the plane passing through the axis, to draw a tangent to the curve at a given point. Fig. 6. Let B P K be the projection of the helix or screw, and B A the projection of the circumference of a circle, and since this circle is in a plane perpen- dicular to the plane of projection, it will be projected into a straight line A B, equal to the diameter of the cylinder. On A B, as a diameter, describe the semicircle I'll:. ri'<'. 1. />''/ '/'//' si/nwrrs I'l' S,'//'i/s jt-^ /■ IVfXo.i'ltmS': PRACTICAL GEOMETRY. 59 A. r B, and draw P r perpendicular to, and inter- secting, A B in q, join tlio points e r, and produce e r to /. Produce A B to C, so that B C may be equal to the semicircular arc B r A. Draw C D perpendic- ular to B C, and make C D equal to A K, and draw the straight line B D ; then B D will be the devel- opment of the curve line B P K. Dra\\- P ti parallel to A C, meeting B D in u, and draw u t perpendicular to B C. Draw r g perpen- dicular to e ;•, and make r g equal to B t. Draw g n perpendicular to A C, meeting B C in n, and draw the straight line n P ; then n P will touch the curve at the point P. Or the tangent may be drawn independent of BCD, thus : Draw P r perpendicular to A B, and r g a tangent at r. Make r g equal to the development of r B, and draw g n perpendicular to B C, meet- ing B C in n, and join n P, which is the tangent required. PEELIMINARY PRINCIPLES OF PROJECTION. PROBLEM. Plate 15. If from a point A', Fig. 1, in space, a perpendic- ular A' a be let fall to any plane P Q whatever, the foot a of this perpendicular is called the projection of the point A' upon the plane P Q. K, through different points A', B', C, D',....Figs. 2, 3, 4, of any line A', B', C, D', . . . . whatever in space, perpendiculars A' o, B' b, C c,T>' d, . be let fall upon any plane P Q, whatever, and if tlu-ough a, b, c, d, the projections of the points A', B', C, D', iji the plane P Q, a line be drawn, the line thus drawn will be the projection of the line A' B' C D' . . . . given in space. If the line A' B' C D' . . . . Fig. 3, be straight, the projection abed. . . . will also be a straight line ; and if the line A' B' C D' . . . . Fig. 2, be a curve not in plane perpendicular to the plane P Q, the curve abed.... which is the projection of the curve A' B' CD',.... in space, will be of the same species with the original curve, of which it is the projection. Hence, in this case, if the original curve A' B' C D' . . . . be an ellipse, a parabola, an hyperbola, &c., the projection abed.... will be an ellipse, a parabola, an hyperbola, &c. The circle and the ellipse being of the same species, the pro- jected curve may be a circle or ellipse, whether the original be a circle or ellipse, as in Fig. 4. The plane in which the projection of any point, line, or plane figure is situated is called the plane of projection, and the point or line to be projected is called the primitive. The projection of a curve will be a straight line when tlie curve to be projected is in a plane perpen- dicular to the plane of projection. Hence the pro- jection of a plane curve is a straight line. If a curve be situated in a plane which is parallel to the plane of projection, the projection of the curve will be another curve equal and similar to the curve of which it is the projection. The projection upon a plane of any curve of double curvature whatever is always a curve line. In order to fi:x the position and form of any line whatever in space, the position of the line is given to each of two planes which are perpendicular to each other ; the one is called the horizontal plane, and the other the vertical plane ; the projection of the line in question is made on each of these two planes, and the two projections are called the two projections of the line to be projected. Thus we see, in Fig. 5, where the parallelogram U V W X represents the horizontal plane, and the parallelogram U V Y Z represents the vertical plane ; the projection a b ot the line A' A' in space upon the horizontal plane U V W X is called the horizontal projeetion; and the projection A B, of the same line upon the vertical plane U V Y Z, is called the verti- eal projeetion. The two planes upon which we project any line whatever are called the planes of projection. The intersection U V of the two planes of projec- tion, is called the ground line. When we have two projections a &, A B of any line A B' in space, the line A' B' will be determined by- erecting to the planes of projection the perpendiculars a A, i B' . . . A A', B B' . . . through the projections a,b, A, B, of the original points A', B'. of the line in question. For the perpendiculars a A', A A' erected from the projections a, A of the same point A' will intersect each other in space in a point A', which will be one of these in the line \v 60 PRACTICAL GEOMETRY. question. It is clear tiiat the other points must be found in the same manner a.s this which has now been done. When we iiavc obtained the two projections of a line in space, whether immediately from the line it- self or by any other means whatever, we must aban- don this line in order to consider its two projections only, since, when we design a working drawing, we operate only upon the two projections of this line that we have brought together upon one plane, and we no longer see any thing in space. However, to conceive that which we design, it is absolutely necessary to carry by thought the opera- tions into space from their projections. This is the most difficult part that a beginner has to surmount, particularly when he has to consider at the same time a great number of lines in various positions in space. The perpendicular A- a, Fig. 5, let fall from any point A whatever in space upon the plane X V of projection, is called the projectant of the point A' upon this plane. Moreover, the perpendicular dis- tance between the point A' and the horizontal plane X V, is called the projectant upon the horizontal plane, or simply the horizontal projectant; and the perpendicular distance A' A between- the original point A' and the vertical plane U Y, is called the pro- jectant upon the vertical plane, or simply the vertical projection. We shall rcmarlc, so as to prevent any mistake, that the horizontal projectant A' a is the perpendic- ular let fall from the original point upon the horizon- tal plane, and that the vertical projectant is the per- dicular let fall from that point upon the vertical plane. Hence the horizontal projectant is parallel to the ver- tical plane, and is equal to the distance between the original point and the horizontal plane; and the ver- tical projectant is parallel to the horizontal plane, and is equal to the distance between the original point and the vertical plane. We may remark, that if through a. Fig. G, the hori- zontal projection of the point A', we draw a perpen- dicular a to U V, the ground line, this perpendicular a will be equal to the measure of the vertical project- ant A' A; consequently, the distance of the point A' to the vertical plane is equal to the distance between a, its horizontal projection, and U V, the ground line measured in a perpendicular to U V. In like man- ner, if through A, the vertical projection of the point A', wc draw a perpendicular A a to U V, the ground line, this perpendicular A a will be equal to the measure of the horizontal projectant A o; conse- quently, the distance of this point A' to the horizon- tal plane is equal to the distance between A, its ver- tical projection, and U V, the ground line measured in a perpendicular to U V. To these very important remarks we shall add one which is not less so. Two perpendiculars, a a, Fig. 6, A a, being let fall from the projections a, A to the same point A' upon the ground line U V, will meet each other in the same point a, of the said ground line U V. If we now wished the two projections of a point A', Fig. 6, or of any line A' B' whatever, to be upon one or the same plane, it is sufficient to imagine the vertical plane U V Y Z to turn round the ground line U V in such a manner as to be the prolongation of the horizontal plane U V W X; for it is clear that this plane will carry with it the vertical projection A or A B of the point, or of the line in question. More- over, we see, and it is very important, that the lines A a, B b, perpendicular to the ground line U V, will not cease to be so in the motion of the plane U V Y Z ; and as the corresponding lines « a, i b, are also perpendiculars to the ground line U V, it follows that the lines a a', b b', will be the respective pro- longation of the lines a a, i b. Hence it results, when we consider objects upon a single plane, the projections a A, of a point A' in space, are necessarily upon the same perpendicular A a to the ground line U Y. It is necessary to call to mind that the distance A a, measures the distance from the point in space to the horizontal plane, (the point A being the vertical projection of this point,) and that the line a a meas- ures the distance from the same point in space to the vertical plane. It follows, that if the point in space be upon the horizontal plane, its distance with regard to this last- named plane will be zero or nothing, and the vertical A a will be zero also. Moreover, the vertical projection of this point will be upon the ground line at the foot a, of the perpendicular a a, lot fall upon the ground line, from the horizontal projection a of this point. Again : if the point in space be upon the vertical plane, its distance, in respect of this plane, will be zero, the horizontal a a will be zero, and the hoiizon- tal projection of the point in question will be the foot PRACTICAL GEOMETRY 61 a, of the perpendicular A a, let fall upon the ground line from the vertical projection A, of this point. In general, we suppose that the vertical projection of a point is above the ground line, and that the horizontal projection is below ; but from what has been said, it is evident that, if the point in space be situated below the horizontal line, its vertical projec- tion will be below the ground line ; for the distance from this point to the horizontal plane cannot be taken from the base line to the top, but from the top to the base with respect to its plane. So if the point in space be situated behind the vertical plane, its horizontal projection wUl be above the ground line; from which we conclude, — 1. K the point in question be situated above the horizontal plane, and before the vertical plane, its vertical projection will be above, and its horizontal projection below, the ground line. 2. If the point be situated before the vertical plane, and below the horizontal plane, the tw'o projections will be above the ground line. 3. K the point be situated above the horizontal plane, but behind the vertical plane, the two projec- tions wiU be above the ground line. . 4. Lastly. If the point be situated above the hori- zontal plane, and behind the vertical plane, the verti- cal projection will be below, and the horizontal pro- jection above, the ground line. The reciprocals of these propositions are also true. If a line be parallel to one of these planes of pro- jection, its projection upon the other plane will be parallel to the ground line. Thus, for example, if a line be parallel to a horizontal plane, its vertical pro- jection will be parallel to the ground line ; and if it is parallel to the vertical plane, its horizontal projection wiU be parallel to the ground line. Reciprocally, if one of the projections of a line be parallel to the ground line, this line will be parallel to the plane of the other projection. Thus, for ex- ample, if the vertical projection of a line be parallel to the groimd line, this line will be parallel to the horizontal plane, and vice versa. If a line be at any time parallel to the two planes of projection, the two projections of this line will be parallel to the ground line ; and reciprocally, if the two projections of a line be parallel to the ground line, the line itself will be at the same time parallel to the two planes' of projection. K a line be perpendicular to one of the planes of projection, its projection upon this plane will only be a point, and its projection upon the other plane will be perpendicular to the ground line. Thus, for ex- ample, if the line in question be perpendicular to the horizontal plane, its horizontal projection wiU be only a point, and its vertical projection will be perpendic- ular to the ground line. Reciprocally, if one of the projections of a straight line be a point, and the projection of the other per- pendicular to the ground line, this line will be per- pendicular to the plane of projection upon which its projection is a point. Thus the line will be perpen- dicular to the horizontal plane, if its projection be the given point in the horizontal plane. K a line be perpendicular to the ground line, the two projections will also be perpendicular to this line. The reciprocal is not true ; that is to say, that the two projections of a line maybe perpendicular to the ground line, without having the same line perpendic- ular to the ground line. K a line be situated in one of the planes of pro- jection, its projection upon the other will be upon the grovmd line. Thus, if a line be situated upon a hori- zontal plane, its vertical projection will be upon the ground line ; and if this line were given upon the vertical plane, its horizontal projection would be upon the ground line. Reciprocally, if one of the projections of a line be upon the ground line, this line will be upon the plane of the other projection. Thus, for example, if it be the vertical projection of the line in question, which is upon the ground, this line will be upon the hori- zontal plane ; if, on the contrary, it were upon the horizontal projection of this line which was upon the ground line, this line would be upon the vertical plane. If a line be at any time upon the two planes of projcctioM, the tA.vo projections of this line would be upon the ground line, and the line in question would coincide with this ground line. Reciprocally, if the t^vo projections of a line were upon the ground line, the line itself would be upon the ground line. If two lines in space are parallel, their projections upon each plane of projection are also parallel. Re- ciprocally, if the projections of two lines are parallel on each plane of projection, the two lines will be parallel to one another in space. If any two lines whatever in space cut each other, the projections of their point of intersection will be 62 PRACTICAL GEOMETRY upon the same perpendicular line to the ground line, and upon the points of intersection of the projections of these lines. Reciprocally, if the projections of any two lines whatever cut each other in the two planes of projection in such a manner that their points of intersection are upon the same perpendic- ular to tlie ground line, these two lines in question will cut each other in space. The position of a plane is determined in space when we know the intersections of this plane with the planes of projection. The intersections A B, A C, of the plane in ques- tion, witli the planes of projections, arc called the traces of this plane. The trace situated in the horizontal plane is called the horizontal trace, and the trace situated in the ver- tical piano is called the vertical trace. A very important remark is, that the two traces of a plane intersect each other upon the ground line. If a plane be parallel to one of the planes of pro- jection, this plane wiU have only one trace, which will be paraDel to the ground line, and situated in the other plane of projection. Reciprocally, if a plane has a trace parallel to the ground line, this plane will be parallel to the plane of projection, which docs not contain this trace. Thus : — 1. If a plane be parallel to the horizontal plane, this plane will not have a horizontal trace, and its vertical trace will be parallel to the ground line. Likewise, if a plane be parallel to the vertical plane, this piano will not have a vertical trace, and its hori- zontal trace will be parallel to the ground line. 2. If a plane has only one trace, and this ti-ace parallel to the ground line, let it be in the vertical plane ; then the plane will be parallel to the horizon- tal plane. So if the trace of the plane be in the horizontal plane, and parallel to the ground line, the plane will be parallel to the vertical plane. . If one of the traces of a plane be perpendicular to the ground line, and the other trace in any position whatever, this plane will be perpendicular to the plane of projection in which the second trace is. Thus, if it bo a horizontal trace which is perpendic- ular to the ground line, the plane will be perpendic- idar to the vertical plane of projection ; and if, on the contrary, the vortical trace be that which is per- pendicular to the ground line, tiien the plane will be perpendicular to the horizontal plane. Reciprocally, if a plane be perpendicular to one of the planes of projection, without being parallel to the other, its trace upon the plane of projection, to which it is perpendicular, will be perpendicular to any posi- tion whatever, and the other trace will be perpendic- ular to the ground line. Thus, for example, if the plane be perpendicular to the vertical plane, the ver- tical trace will be perpendicular to the ground line. The reverse will also be true, if the plane be perpen- dicular to the horizontal plane. If a plane be perpendicular to the two planes of projection, its two traces will be perpendicular to the ground line. Reciprocally, if the two traces of a plane are in the same straight line perpendicular to the ground line, this plane will be perpendicular to both the planes of projection. If the two traces of a plane are parallel to the ground line, this plane will be also parallel to the ground line. Reciprocally, if a plane be parallel to the ground line, its two traces will be parallel to the ground line. When a plane is not parallel to either of the planes of projection, and one of its traces is parallel to the ground line, the other trace is also necessarily par- allel to the ground line. If two planes arc parallel, their traces in each of the planes of projection will also be parallel. Recip- rocally, if on each plane of projection the traces of the two planes are parallel, the planes will also be parallel. If a line be perpendicular to a plane, the projec- tions of this line will be in each plane of projection perpendicular to the respective traces in this plane. Reciprocally, if the projections of a line are respec- tively perpendicular to the traces of a plane, the line will be perpendicular to the plane. If a line be situated in a given plane by its traces, this line can only intersect the planes of projection upon the traces of the plane which contains it. Moreover, the line in question can only meet the plane of projection in its own projection. Whence it follows, that the points of meeting of the right line, and the planes of projection, arc respectively upon the intersections of this right line, and the traces of the plane which contains it. K a right line, situated in a given plane by its ti-aces, is parallel to the horizontal plane, its horizon- tal projection will be parallel to the horizontal trace of the given plane, and its vertical projection will be parallel to the ground line. Likewise, if the right PRACTICAL GEOMETRY. 63 line situated in a given plane by its traces is parallel to the vertical plane, its vertical projection will be parallel to the vertical line of the plane which con- tains it, and its horizontal projection will be parallel to the ground line. Reciprocally, if a line be situated in a given plane by its traces, and, for example, its horizontal pro- jection be parallel to the horizontal trace of the given plane, this line will be parallel to the horizon- tal plane, and its vertical projection wiU be parallel to the ground line. Liliewise, if the vertical projec- tion of the line in question be parallel to the vertical trace of the given plane, this line will be parallel to the vertical plane, and its horizontal projection wiU be parallel to the ground line. SECTION On the Developments of the Surfaces of Solids. PROBLEMS. Plate 15. PROBLEM I. To find tlie development of the surface of a right semi-cylinder. Fig. 1. Let A C D E be the plane passing through the axis. On A C, as a diameter, describe the semi- circular arc ABC. Produce C A to B, and make A F equal to the development of the arc ABC. Draw F G parallel to A E, and E G parallel to A F ; then A F G E is the development required. PROBLEM II. To find the development of that part of a semi- cylinder contained between two perpendicular surfaces. Figs. 2, 3, 4. Let A B C D E be a portion of a plane passing through the axis of the cylinder, C D and A E being sections of the surface, and let D E and F G be the insisting lines of the perpendicular sTirface ; also, let A C be perpendicular to A E and C D. On A C, as a diameter, describe the semicir- cular arc ABC. Produce C A to H, and make A H equal to the development of the arc ABC. Divide the arc ABC and its development each into the same number of equal parts, at the points 1, 2, 3. Though the points 1, 2, 3, &c., in the semicircular arc, and in its development, draw straight lines par- allel to A E, and let the parallel lines through 1, 2, 3, in the arc ABC, meet F G in p, rj, r, Sec, and A C in k, I, m, &c. Transfer the distances Icp, Iq, vir, &c., to the development upon the lines 1 a,2 b,3 c, &c. Through the points F, a, b, c, &c., draw the curve line F c 1. In the same manner draw the curve line E K ; then F E I K will be the development re- quired. PROBLEM III. To find the development of the half surface of a right cone, terminated by a plane passing through the axis. Fig. 5. Let A C E be the section of the cone pass- ing along the axis A E, and C E the straight lines which terminate the conic surface, or the two lines which are common to the section C A E and the conic surface ; and let A C be the line of common section of the axal plane and the base of the cone. On A C, as a diameter, describe a semicircle, ABC. From E, with the radius E A, describe the arc A F, and make the arc A F equal to the semi- circular arc ABC, and join E F; then the sector A E F is the development of the portion of the conic surface required. PROBLEM IV. To find the development of that portion of a conic surface contained by a plane passing along the axes, and two surfaces perpendic- ular to that plane. Fig. 6. Let A C E be the section of the cone along the axis, and let A C and G I be the insisting lines of the perpendicular surfaces. Find the devel- opment A E F, as in the preceding problem. Divide the semicircular arc ABC, and the sectorial arc A F, each into the same number of equal parts at the points 1, 2, 3, &c. From the points 1, 2, 3, &c., in the semicircular arc, draw straight Lines, 1 k, 2 /, 3 m, &c., perpendicular to A C. From the points k, I, m, &c., draw straight lines, A; E, Z E, m E, Sec, intersecting the curve A C in j?, q, r, &c. Draw the straight lines pt, qu, rv, &cc, parallel to one side, E C meeting A C in the points t, u, v, Sec Also from the 64 PROJECTION OF PRISMS. points 1, 2, 3, in the sectorial arc A F, draw the straight lines 1 E, 2 E, 3 E, &c. Transfer the dis- tances pt, qii, rv, &c., to 1 a, 2 b, 3 c, &cc. ; then, through the points A, a, b, c, &c., draw the curve A c F, and A c F is one of tlie edges of the develop- ment, and by drawing the other edge, the entire de- velopment, A G H, will be found. Note. — This treatise on the subject of Geometry we have thought best to insert in the form in which it was fiist written. It is a system in a degree peculiar to its author, and it is, without doubt, the production of a laborious research ; and although the same conclusions would, in some cases, be arrived at by the more direct process of demonstration used at the present day, yet, from its extent and completeness, we have concluded, as a whole, that no part could be materially changed for the better without seriously intruding upon the theories of our venerable author, and that, too, at the expense of interfering with liis style of writing, wliich will at once be recognized as the original. We will state here, that we have endeavored, as much as possible, to preserve every idea that he has advanced, and that, toO; in his own language. — Editors. PROJECTION or PRISMS. In the annexed definitions and problems, the student will find enough to give him a correct and sufficiently perfect idea of the nature and importance of this useful branch of science ; and he will also find occasion to apply the geometrical principles, a knowl- edge of which he is presumed to have acquired from the preceding pages of the present work. DEFINITIONS. 1. When straight lines are drawn according to a certain law from the several parts of any figure or object cut by a plane, and by that cutting or inter- section describe a figure on that plane, the figure so described is called the projection of the other figure or object. 2. The lines taken altogether, which produce the projection of the figure, are called a syatem of rays. 3. When the system of rays are all parallel to each other, and are cut by a plane perpendicular to them, the projection on the plane is called the orlhog- raphy of the figure proposed. 4. When the system of parallel rays is perpendic- ular to the horizon, and projected on a plane parallel to the horizon, the orthographical projection is then called the ichnography, or plan of the figure proposed. 5. When the rays of the system are parallel to each other and to the horizon, and if the projection be made on a plane perpendicular to those rays and to th(! horizon, it is called the elevation of the figure proposed. [In this kind of projections, the projection of any particular point or line is sometimes called the seat of that point or line, on the plane of projection.] G. If a solid be cut by a plane passing quite through it, the figure of that part of the solid which is cut by the plane is called a section. 7. When any solid is projected orthographieally upon a plane, the outline or boundary of the projec- tion is called the contour or profile of the projection. Note. — Although the term orthography signifies, in general, the projection of any plane which is perpendicular to the projecting rays, without regarding the position of the plane on which the ob- ject is projected, yet writers on projection substitute it for elevation, as already defined, by which means it will be impossible to know when we mean that particular position of orthographical projection which is made on a plane perpendicular to the hori/on. Axiom. — K any point, line, or plane of any origi- nal figure or object touch the plane on which it is to be projected, the place where it touches the pro- jecting plane is the projection of that point, line, or plane of the original figure or object. Proposition. — The orthographical projection of a line which is parallel to the plane of projection is a line equal and parallel to its original. PROBLEMS. Plate 16. PROBLEM I. To project the elevation of a prism standing on a plane perpendicular to the projecting plane ; giA'en, the base of the prism and its position to the projecting plane. Fig. 1. Let A B C D, No. 1, be the base of the prism ; let H F be the intersection of the projecting plane, with the plane on which the prism stands. Draw lines from every angle of the base, cutting T K fw /.]■■■/ PEOJECTION OF PRISMS. 65 H F at H, and F will be the projection of the points A and C ; the angle D, touching H F at D, is its projection. From each of the points H, D, F, in No. 2, draw the lines H I, D E, and F G, each perpendiciilar to H F ; make D E eqnal to the height of the prism ; through E di'aw I G, cutting H I and F G at I and G, which will give the projection sought. PROBLEM II. To project the ichnograpliy and elevation of a square prism, to rest upon one of its angles upon a given point A, in the plane, on which tlie ichnography is to be described ; given the ichnograpliy A L, of an angle, wliich the two under planes make with each other; the angle ]\I a I, which the angle of the solid makes with its ichnography A L ; the inter- section A a of one of its ends with the plane of the ichnography ; the angle D A «, which one side of the end makes at A, with the in- tersection A a of that end ; also given one of the sides of the ends, and the length of the prism. Fig. 2. At the given point A, with the intersection A a, make an angle a AT>, equal to the angle which one of the sides of the end makes with A a; make A D equal to one of the sides of the end; then on A D consti-uct the square A B C D ; through the angles of the square B, C, D, draw lines B H, C I, and D M, parallel to A L ; then at the point a, in the right line D M, make an angle M a 1, with a M, equal to the angle of the solid, whose projection is A L, with A L ; make a I equal to the length of the 9 solid ; through the points a and /, No. 1, draw the lines a e and I i perpendicular to a I ; through the points B and C, No. 2, draw B R and C S parallel to A a, cutting D M, produced at E, and S ; on a, as a cen- tre, with the distances a D, a R, and a S, describe ares V g, R/, and S e, cutting a e, No. 1, at g-, /, e ; through the points g, f, e, draw the lines g- k, f h, and e i, parallel to a I, and No. 1 will be completed, which will be the projection of tlie prism on a plane parallel to A L. Through the points g, f, e, draw the lines e E, / F, and g G, perpendicular to D M, or A L, cutting D E, C I, and B H, respectively, at G, E, F; also through the points I, k, h, i, cbaw the lines I L, k K, h H, and i I, Hkewise parallel to A L, cutting A L, G M, B H, and C I, respectively, at the points L, K, H, and I ; join E F, E G, and H I, I K, K L, L H, then will the planes E F H I, E I K L, and H I K L represent the ichnogi-aphy of the upper sides of the solid ; and if F A and A G be joined, then will F A G E, F A L H, and G A L K represent the sides of the solid next to the plane of projection. Then to project the elevation on a plane whose intersection is T U, from F, E, G, A, H, I, K, and L, that is, from all the points in the ichnography representing the solid angles, di-aw the lines F /, E e, G^, A o, H h, I i, K k, and L I, per- pendicular to the intersection T U, cutting T U at P> 5') (^> §"> o, m, and k ; make p f^ q e, g g,n h, o i, m I, and k k, at No. 3, respectively, equal to P/, Q e, G g-, N A, O i, M I, and K k, at No. 1 ; then join f a, a g, g e, e f; e i, i k, k g, k I, and la; and fage, geik, gkla will be the elevations of the outside planes of the solid; and by joining/ A, and h i,fh i e,fh I a, and i h I k will be the elevations of the planes of the solid next to the plane on which the elevation is projected. 66 SHADOWS SHADOWS. This' is one of the most interesting branches of architectural sci- ence I or perhaps it may, with more propriety, be termed a branch of geometry, for it is almost entirely dcpenilent on, and governed by, geometrical principles. From a knowledge of it the architect is enabled to draught his plans, and to give them their true effect, or representation of light and shade ; to construct his windows in order to receive light to the best advantage, &c., &c. The art of keeping a proper gradation of light and shade on objects, according to their several distances, colors, and other circumstances, is of the utmost consequence to the artist. THE EFFECT OF DISTANCE ON THE ' COLOR OF OBJECTS. The art of giving a due diminution or degradation to the strength of the light and shade and colors of objects, according to the different distances, the quan- tity of light which falls on their surfaces, and the medium through which they are seen, is called keeping;. 1. When objects are removed to a gi-cat distance from the eye, the rays- of light Avhicli they reflect will be less vivid, and the color will become more diluted, and tinged wiih a faint bluish cast, by rea- son of the great body of air through which they are seen. 2. In general, the shadows of objects, according as they are more remote from Hie eye, will be lighter, and the light parts will become darker ; and at a certain distance the light and shadow are not distin- guishable from each other, for both will seem to ter- minate in a bluish lint of the color of the atmosphere, and will appear entirely lost in that color. 3. If the rays of light fall upon any colored sub- stance, the reflected rays will be tinged with the color of that substance. 4. If the colored rays be reflected upon any object, the color of that object will then be compounded of the color of the reflected rays and the color of the object ; so that the color of the object which receives the reflection will be changed into another color. 5. From the closeness or openness of tlie place where the object is situated, the light, being much more variously directed, as in objects which are sur- romidcd by buildings, will be more deprived of re- flection, and, consequently, will be darker than those which have no other objects in their vicinity, except the surrounding objects are so disposed as to reflect the rays of light upon them. 6. In a room, the light being more variously di- rected and reflected than abroad in the open air, (for every apertm-e gives an inlet to a different stream,) which direction is various, according to the place and position of the apertm-e, whereby every diflcrent side of the room, and even the same side in such a situa- tion, will be variously afTected with respect to their light, shade, and colors, from what they would in an open place when exposed to rays coming in the same direction. Some original colors naturally reflect light in a greater proportion than others, though equally ex- posed to the same degrees of it, whereby their degra- dation at different distances will be different from that of other colors which reflect less light. The art of keeping a degradation of light and shade on objects, according to their several distances, colors, and other circumstances, is of the utmost conse- quence to the artist. In orthographical projections, where equal and similar objects stand in the same position to the plane of projection, they will be represented similar, and of an equal magnitude at every distance from that plane ; and, consequently, planes wliich are par- allel to each other would not appear to have any dis- tance, so that the representation of any number of objects, at different distances from each other, would be entirely confused, and no particular object could be distinguished from the others ; but, by a proper attention to the art of kccpitig;, every object will be distinct and separate, and their respective distances and colors from each other will be preserved. But though a proper degradation of light and shade ought to be preserved, according to the respective distances of objects from each other, artists in general take too gi"cat liberties with nature : we frequently see in the drawings of architects the art of keeping carried to so great an extreme as to render their performances ridiculous. SHADOWS. 67 DEFINITIONS. 1. A body which is continually emitting a stream of matter from itself, and thereby rendering objects visible to our sense of seeing, is called a luminary; such as the sun, or any other body producing the same effect. 2. The stream of matter which is emitted from the luminary is called light. 3. A substance or body which light cannot pene- trate is called an opaque hodij. 4. If a space be deprived of light by an opaque body, it is called a shade. 5. The whole or part of any sm-face on which a shade is projected is called a shadow. 6. A body which will admit of light to pass through it is called a transparent substance. 7. A line of light emitted from the luminary is called a ray. Proposition 1. — The rays of light, after issuing from the luminary, proceed in straight lines. Proposition 2. — If the rays of light fall upon a re- flectiiig plane, the angle made by any incident ray, and a perpendicular to the reflecting plane, is called the angle of incidence, and ■wHl be equal to the angle that its reflected ray will make with the same per- pendicular, called the angle of reflection ; these two propositions are known lirom experiment. Proposition 3. — If the rays of light fall upon any curved surface, whether concave or convex, or mLxed of the tvs^o, the angle of reflection will stiU be equal to the angle of incidence. Proposition 4. — Any uneven reflecting surface, whose parts lie in various directions, will reflect the rays of the sun in as many different directions. Demonstration. — If any ray fall upon a part of the surface which is perpendicular to that ray, it will be reflected m the same line as the incident ray ; but the more or less any part of the surface is inclmed to a ray, falling upon that part of the surface, the greater or less angle will the reflected ray make with the in- cident ray. For imagine a perpendicular to be erected to that part of the surface where any incident ray impinges on the surface, it is evident that the meas- ure of the angle of incidence is equal to the obtuse angle made by the incident ray, and the reflecting surface at the impinging point made less by a right angle ; but the angle of reflection is equal to the an- gle of incidence ; wherefore it follows that the whole angle formed by the incident and reflected rays is double of the angle of incidence ; and, consequently, a reflecting surface, whose parts lie in various direc- tions, wiU reflect the sun's rays in as many directions. Corollary. — Hence appears the reason why objects and their parts become visible to our sight when im- mersed ui shade. SEAT OF THE SUN'S RAYS. DEFINITIONS. 1. If a given straight line pass through or cut a given plane, and if an imaginary plane be supposed to pass through any two points m the straight Ihie, perpendicular to the other plane, the angle made by the intersection of the two planes and the given straight line is called the inclination or altitude of the given line on the given plane. 2. The intersection of the planes is called the seat of the given line on the given plane. Corollary. — The angle made by a ray of light, and the seat of that ray, is the angle of the sun's in clination. 3. If on the surface of any solid there be any point or points in the surface where the sun's rays fall per- pendicular, this point or points which the sun's rays fall perpendicular to are called points of light. 4. If on the sm-face of any solid there be any Ime drawn upon that surface, and if the line so drawn upon the surface be lighter than any other line that can be drawn upon the said surface, then the line first drawn is called the line of light. 5. K the sun's rays fall upon any solid, and if a line or lines be drawn on the surface of the solid where the sun's rays are a tangent, or upon the place or places of the surface which divide the dark side from the light side, then the line or lines so described are caUed a line or lines of shade. 6. If the sun's rays be parallel to any plane, that plane to which they are parallel is called a plane of shade. PROBLEiAIS. PROBLEM I. Given the ichnography aud elevation of a prism, whose sides stand perpenchcular to the hori- zon, and whose ichnography is a figure of 68 SHADOWS. an) kind, regular or irregular ; given the scat of the sun on the ichnography, also on the elevation, and the intersection of the plane of the elevation with the plane of the ichnog- raphy; the representation of the point being likewise given on the elevation, and also on the ichnography, to determine the representa- tion of the shadow on the elevation. Through the representation of the given point in the plane of tlie ichnography ckaw a line parallel to the scat of the sun's rays on that plane, and produce it till it cut the intersection ; from that point on the elevation draw a line perpendicular to the intersec- tion ; then through the representation of the given point on the elevation draw a line parallel to the sun's seat on the elevation, cutting the line that was di-awn perpendicular to the intersection, and that point will be the representation of the shadow on the elevation. Plate 17. PROBLEM 11. Given the altitude and seat of the sun on the horizon and the intersection of a plane, mak- ing a given angle with the horizon ; to find the seat and altitude of the sun on the other plane. Fig. 1. Let D F be the seat of the sun on the horizon, and D F G the angle of the sun's elevation, E F the intersection of the plane with the horizon, and ABC the angle which that plane is to make with the horizon. Produce D F till it meet E F in F ; through any point D, in the seat D F, draw D G perpendicular to D F, cutting F G in G ; also, through D draw D K perpendicular to E F, cutting E F in E ; through D draw D I perpendicular to D K; make the angle D E 11 equal to the given angle ABC; make D I equal to D G ; through I draw I H perpendicular to E H, cutting it in II; make E K equal to E II; join K F ; fi'om K make K L perpendicular to K F ; from K make K L equal to H I ; join L F ; then will I K be the scat of the sun on the other plane, and K F L will be the angle of the altitude. If the plane KEF stands perpendicular to the horizon, as m Fig. 2, the operation will be more sim- ple, as follows, the same letters standing for the same things : — Make E K equal to D G ; join K F ; draw K L, as before, and make K L equal to D E ; join L F ; then will K F be the seat of the sun on the horizon, and K F L be the seat of the altitude. Plate 18. PROBLEM UI. Given the ichnography A B C D E F G H I K, and elevation L M N O, of an upright prism, whose base or ichnography is a regular poly- gon, and the seat of the sun's rays on the base, to determine the various degrees of light and shade on the different sides of the prism. Fig. 1. Let P Q, in the ichnography, be the seat of the sun ; and if it cut C D perpendicular, then will C D be the lightest side of the prism ; the sides D E and C B will be a small degree darker, as P Q is more inclined to D E and C B ; and in general, ac- cording as the sides recede on each side of C D, they wiU be contintially darker untU they become wholly deprived of light ; then suppose the sun's ray to touch the side G H, then G H -will be the plane of shade, or that side where the light wiU end. Much in the same manner may the different de- grees of shade be found on the surface of a cylinder, as in Fig. 2, where A B C D is the ichnogi-aphy, and G H I K the elevation ; that is, if B P be the direc- tion of the sun's rays, cutting the ichnogi-aphy in B. then will B be the lightest place ; and it will be con- tinually darker and darker in each side of the pomt B, until it arrives at the point C, where the ray touches the side of the cylinder, and there the light will end and the darkness begin. PROBLEM IV. To represent the boundaries of light and shade on the ele^■ation of a cone illumined by the sun, given the angle that any ray of light takes with the base of the cone ; also to determine the line of light, or that place on the surface that will be the lightest. Figs. 3 and 4. Let A E D be the elevation of the cone, and let F I L G be the ichnography or base of the cone ; let F L be the seat of any ray in a plane II 17 ,111 «!ll'J. Through the points (/, w, n, u, draw the lines d, g, m, e, n, o, and v, v, perpendicular to the diameters B H, E I, F K, and G L, cutting B H, E T, F K, and G L, respectively at the points g; c, o, v ; draw a curve which will be part of the line of light for one quarter ; also through the points '. L* \¥ i '' : i i ... ■' '/ \n\ ..- ,<•' ' Fi)>. 1 . % 1 N''\l. y ::■-». i '' 1 \K.V; -> N> ■ : \ ] V: : :■■ \ II 3Jv' : '• I'.'T Si^. i /&. / I'l SMAiD.SWS D^z lllllllllllllllllllIlllllllllllllllllllllllllllllllllllllllllllllllllJllllllllllllllll^lP^ SHADOWS. 78 are placed on the ichnography and elevation, repre- senting the correspondiiig parts of each other ; that is, capital letters are placed on the ichnography, and small letters of the same name on the elevation, representing those of the same name on the ichnog- raphy. PROBLEM XI. Given the seat and altitude of the sun on any plane, also the seat and altitude of a Ime to the same plane ; to determine the shadow of the line upon that plane. Let K L be the seat of the line upon the plane, and G H, Fig. 3, the angle wliich the line makes with its seat ; make the angle M K L, Fig. 2, equal to the angle H G I ; through L draw L M, perpen- dicular to K L, cutting K M at M ; also, through L draw L O parallel to the seat of the sun. Again : through L draw L N perpendicular to L O, and make L N equal to L M ; then upon the right line L N, and from the point N, make the angle L N O equal to the complement of the angle of the sun's inclination to a right angle ; produce N O, cutting L O at O; then join the points K and O, and the line K O will be the shadow required. Tliis problem will be found of great use in finding the shadows upon inclined planes. XoTE. If the seat and altitude of the 8>in be given on any other plane, making a given angle ■with the plane on which the shadow is to be projected, the sun's altitude and seat may be found by Problem II. PROBLEM XII. Given the seat and angle of inclination of the sun on the horizon, and the intersection of a plane perpendicular to the horizon ; to de- termine the angles which a plane of shade, made by a right line, parallel both to the horizontal and perpendicular planes, will make with each of the planes. Let A B be the seat of the sun on the horizon, and A A D, as Fig. 1, the angle of inclination to the seat A B, and let C B be the intersection of a plane per- pendicular to the horizon ; take any point C in C B, and from C draw C A perpendicular to C B, cutting A B at A ; from A, draw A E perpendicular to A C, 10 and A D perpendicular to A B, cutting D B at D ; make A E equal to A D, and join C E ; then will the angle B C E be the angle which the plane of shade makes with the perpendicular plane, and the angle ACE the angle which the plane of shade makes with the horizon. This problem will be very useful in shading mould- iiigs which project from planes that stand perpendic- ular to the horizon, the sun's altitude and seat beinc given to the horizon, as will be shown in the next problem. Plate 32. PROBLEM XIII. A moulding of any kind being given, and the angle which a plane of shade makes with a perpendicular part of the moulding, either being given or found by the last problem, ha^ing the sun's altitude and seat on the horizon; to deteimine the shadow on the moulding. Let the ovolo, fillets, and hollow. Fig. 1, be the given moulding ; draw C D parallel to the inclination which the plane of shade makes with the vertical part of the moulding, touching the ovolo at C, and cutting the vertical part below D ; then a line drawn through D perpendicular to the fillet will give the lower edge of the shadow, and an imaginary line, supposed to be drawn through C, will give the line of shade ; and if a line is drawn through A, the lower edge of the fillet above the ovolo parallel to C D, cutting the ovolo at G, then a line being drawn through B, parallel to the fillet, will give the edge of the shadow from the fillet. Much in the same manner, may the shadow upon the cima reversa and cima recta be found, as shown by the dotted lines. ON MOULDINGS Plate 22. The form or shape of mouldings, in most cases, may be ascertained from the various degrees of light and shade upon them, without ob- 74 SHADOWS. serving the profiles; which will appear evi- dent from the following observations: — Observations on Surfaces, and their Poiver to reflect Light. It has already been observed in the second propo- sition, that if the sun's rays fall upon a reflecting plane, the angles made by the reflected rays, with perpendiculars at the impinging points, will be equal to the angles made by their corresponding incident rays with the said perpendiculars ; so that the rays in this case will have only one direction after reflec- tion : but by experiment wc are shown that there is no such thing as a perfect plane ; for, if a sm-face is even polished to the greatest degree, yet this polished surface will be but rough and uneven ; for, if viewed through a microscope having a great magnifying power, the surface will appear quite irregular, and the different parts of the surface will be inclined to any fixed plane, in all manner of directions; and, consequently, if the sun's rays fall upon such a sur- face, the rays will not be enthrely reflected in the same direction, but a great part of them will be reflected in all manner of directions by the different positions of the surface, by Proposition IV. It may be ob- served, that the higher any surface can be polished, the nearer it approximates to a plain, and, conse- quently, the rays wUl be more and more reflected in the same direction ; but there is no surface which will reflect the sun's rays entirely in the same direc- tion ; that is, parallel to each other ; but a great part of them will be reflected in all manner of directions : it will be also necessary to observe, that the power of reflection will depend very much on the lightness of the color of materials ; for the darker any sub- stance iS; the more will the rays of light be absorbed in that substance, and, consequently, will have a less power to reflect. White, being the lightest of all colors, will reflect the most rays ; and the more any substance inclines to a white, the greater power wiU that surface have to reflect the rays of light. CASE I. Observations on Mouldings in Shade. If the sun's rays fall upon any building, also upon the ground or horizon below the building, and if there are any projectures from the building, such as mouldings or other ornaments, and if any of the parts of those mouldings or ornaments are entirely in shadow by the projecture of somethmg else which prevents the rays of the sun from falling upon them, those parts of the mouldings which are in shade will become visible; for, besides a reflection from the ground, there will be a strong reflection from the surface of the Iniilding, immediately under the mouldings or ornaments. It has already been ob- served, that these rays will be reflected in all direc- tions, and, consequently, a part of them wiU be re- flected upwards on the mouldings above, and, there- fore, will show hght and shade on the mouldings according as the reflected rays fall, more or less, per- pendicular on their surfaces. Hence the reason why all perpendicular sides of fillets will be darker in shade than the horizon- tal sides. An ovolo, having a projecture over it, so as to pre- vent the sun's rays from falling upon it, the reflected rays being more and more mclined from the under edge towards the upper edge, wiU be lightest below, and will be gradually darker and darker upwards. A cavctto or hollow, immersed m shade, will, for the same reason, be darkest below, and will be con- tinually lighter to the upper edge. A cima reversa, in shade, will be darkest above and below, and lightest in the middle ; for this moulding is composed of an ovolo above and a cavetto below. A cima recta, in shade, will be hghtest above and below, and darkest in the middle. These are general rules for shading horizontal mouldings. CASE II. Observations on vertical Mouldings. All upright perpendicular mouldings, in shade, or being in part so, will receive a reflection from those smrfaces which are next to them ; for they cannot receive a reflection from the contrary side, by reason of their projection, which wiU prevent the ray, re- flected from that side, from falling on them. Therefore, it is plain, in these cases, the forms of mouldings may be known by reflection. Artists give this rule for shadowing: that is, to shade all mouldings or other ornaments which are in shade, inverse to those on which the sun's rays fall, from the contrary side of the reflected rays. But this rule is not only very uncertain, depending much on the situation of other objects which surround thcs* SHADOWS. 75 mouldings or ornaments, but in some cases very erro- neous, as in the example of mouldings perpendicular to the horizon ; for mouldings in this situation, as has been observed, will receive a reflection from that side which is next to the front of the moulding, if some- thing else docs not project to a great distance from that surface from wliich the reflection comes. K a cylinder or column is attached to a wall in a vertical position, and if it has any projecture over it, so as to cause that part under the projecture to be in shade quite round the cylinder, there will not only be a re- flection from the wall on the contrary side of the cylinder, to the sun upon that side of the cylinder which is next to it, but also from that part of the wall on that side of the cylinder next to the sun, which will make that part of the cylinder which is in shadow lightest at the two sides and darkest in the middle. Something of the same kind may be seen in Ionic columns attached to a wall, where it may be observed when the sun shines upon one side of them ; suppose that side of the column which is on the right hand, then the right hand volute will throw a shadow upon the light side of the column, which shade Avill be lightest on that edge which is next to the wall and to the luminary, and darkest at that edge next to the middle of the column. CASE III. Observations on Mouldings in Shade, when situate on the Side of an Object ivhich is entirely in Shade^ and also the Ground under that Side in Shade. In one building where one end or side is entirely in shade, and also a great part of the ground under that end in shade, there wUl be little or no reflection from the ground upwards, nor from the surface of the building, and, consequently, little reflection upon the mouldings from below ; the only light which they receive is from a kind of scattered or confused rays in the atmosphere, and small reflections from the horizon ; and, therefore, horizontal mouldings, or or- naments, in this situation, which have but small pro- jectures over them, will have a contrary effect to mouldings in shadow situate on the light side of an object. An ovolo, placed horizontally, and whose greatest projecture is upwards, upon the dark side of an ob- ject, will be lightest above, and continually darker and darker to the under edge. A cavello, having its greatest projecture upwards, placed horizontally on the dark side of an object, will be darkest above, and continually lighter and lighter to the under edge. Kcima reversa, placed horizontally on tlie dark side of the object, having its greatest projection upwards, will be darkest in the middle, and lightest above ajid below. A cima recta, whose greatest projecture is upwards, and placed horizontally, will be darkest above and below, and lightest in the middle. All horizontal projectures on the dark side of an object will condense the shade under them, and, con- sequently, will appear more or less dark according as the projecture is more or less. These are general rules for shading mouldings on the dark side of an object from scattered light ; how- ever, there are some exceptions to these rules — that is, when any of these mouldings have a very great projecture over them, this projecture will hinder the scattered rays from falling upon the mouldings ; but as they will receive a small reflection from the hori- zon below, the most of the scattered and reflected rays will fall obliquely on the moulding; thus the lighted place of an ovolo will not be exactly on the under edge, but somewhere between the under and upper edge, and will be nearest to either, ac- cording as the shadow on the ground is less or more distant from that side of the object, and ac- cording as the projecture over the moulding is more or less, and also according to the position and distance of other surrounding objects ; all these different circumstances combining together wUl vary the places of light and shade on horizontal mould- ings, which are situate on the dark side of an object. An horizontal cavetto on the dark side of an object having a projecture over it as before, the lightest place will be somewhere between the upper and under edge, as in the ovolo, and both mouldings would have actually the same appearance if their profiles could not be observed, when most of the scattered and reflected rays are in a plane, making equal angles with the horizon, and with that side of the object in shade — that is, forty-five degrees with each other ; and, consequently, mouldings in this situation will be less distinct than mouldings in shade on that side of the object which the sun shines on. 76 SHADOWS, Further Observations on the Effect that reflected Light tcill have on Cornices which have ModiUions or Mutules, Dentils, Sfc, or any other projecting Or- naments of a Nature similar to them. The reflected light from the ground and from the object being scattered in all directions, it will there- fore follow, if there are any projecting parts from mouldings or cornices, which are in shadows, such as mutules, modillions, dentils, &c., these projecting parts will hinder a great part of the scattered rays from falling in the spaces between them ; and there- fore the spaces will be deprived of reflection, and, consequently, will be much darker than the promi- nent parts, even if these prominent parts were also in shadow. For this reason, the intervals between mutules, mo- dillions, dentils, &c., are darker than on their fronts, for every projecture will condense the shadow on each side of it, if recessed on both sides ; therefore, the spaces will be lightest in the middle, and darkest nearest to the edges of the mutules, modillions, den- tils, &c. ; but to show on which side of the mutules, &c., the greatest shade would fall, according to the place of the luminary, would be almost impossible, as it depends so much on the situation of other ob- jects. But suppose all the surrounding objects in the vicinity to be removed, and the ground and building to be of a light color, and suppose the rays to pro- ceed from the right to the left hand of the object, and parallel to a vertical plane which is inclined at an angle of forty-five degrees with the elevation of the object ; then it is plain that, since the angle of reflec- tion is equal to the angle of incidence, the greatest part of the rays which fall upon the horizon will be reflected from the ground parallel to the vertical plane ; and seeing that the vertical plane would be on the right hand of another vertical plane, perpen- dicular to the face of the object and to the horizon, it follows that most of the rays will come from the right hand, and be reflected towards the left on the object ; and, consequently, any projectures from cor- nices, as mutules, &c., which are in shadow, will con- dense oi darken the shade upon the left hand of the projecture, and that vertical side of the mutules which is next to the luminary will be lighter than the other vertical side on the left of the mutule, &c. As to the direction and effect which most of the re- flected rays would take from the face of the object, imagine a plane parallel to the sun's rays, and per- pendicular to the face of the building or object; then most of the rays will be reflected from the building or object downwards, parallel to this last-mentioned plane ; and that part of those rays which are reflected upwards would take no particular direction to the right or to the left, and, therefore, would cause no sen- sible difference upon the vertical sides of the mutules, but would reflect most light upon the horizontal or under sides, &c. What has now been said of mouldings in shade having projectures from them, or of the recessed parts of any object, will apply to ornaments in shade which are deeply relieved ; for their recessed parts, according to the foregoing observations, will be deprived of reflec- tion by the more prominent parts of them ; they will, therefore, be darkest in their receding parts, and light- est on the prominent parts. Observations on the Shades of Projectures from Buildings, or from any other plain Surface which is made of light Materials. If there is any vertical plane, and if a rectangular prism is attached to that plane, having two of its sides parallel to the plane, — and, consequently, the other two sides perpendiciilar to it, — then, if the sun- shine on the plane be on either side of the prism, the other opposite side of the prism will cause a shadow to be projected from its edge upon the plane ; and if the shadow upon the plane be of ^o considerable breadth, and if the plane be extended at any consid- erable distance beyond the shadow, then the lightest part of the plane on which the rays fall will reflect a great part of the rays towards the prism ; but as these reflected rays will not fall upon the shadow, it will be deprived of reflection ; but as the side of the prism which projects the shadow is opposed to the reflected rays, that side of the prism will receive a strong reflection, which will cause it to appear much lighter than the shadow it throws on the plane ; but if the shadow be projected farther on the plane, it will diminish the reflecting surface behind the prism, and will also cause the reflecting surface to be at a gi'catcr distance from the side of the prism, and, consequent- ly, will receive less reflection from the plane ; and, in general, the reflection on the prism will be continually diminished, according as the shadow on the plane is increased, till at last there will be no difference be- tween the shadow on the plane and the side of the Pl.l'.-J •swM)mv^ M N O V K. l".-l- ::?y>?TSi SHADOWS. 77 prism which projects that shadow ; and if the plane be entirely deprived of light, by the extensive breadth of the shadow, the side of the prism will in general be darker than the shadow on the plane : but this will depend very much on the situation of other objects. A building consisting of light-colored materials, having a break in the front which projects a shadow on the building, at a small distance from the break, will, for the reason before mentioned, be much lighter on the side of the break than the shadow projected by it on the building behind it ; also, columns which are attached to a wall will project a darker shadow on the wall than any part of the columns which throw the shadow, provided that the shadow is not any considerable distance from the column ; for, ac- cording to the above observations, the broader the shadow, the less the column will appear to be relieved from it. Observations on the light Side of the Prism, and the Effect that a Reflection from the Horizon and from the Object will have on the Plane behind the Prism. The rays of the sun being reflected from the hori- zon in all directions, the projecture of the prism will prevent a part of the reflected rays from proceeding to the plane behind the prism, and, consequently, the plane would be something darker than the face of the prism which is parallel to it ; but the side of the prism adjoining to the plane will throw a reflection upon the plane, and, therefore, it would be difficult to perceive the difference between the face of the prism and the plane parallel behind the prism. As to the difference of light between the side of the prism, which is perpendicular to the plane, and the plane, it will very much depend on the situation of the lumi- nary ; for if the luminary is in a plane equally in- clined to both, there will be nearly the same degree of light on each ; for very little difference will arise from the reflection, except the luminary is more in- clined to one surface than another; and then that surface will be darker than the other, accordmg to the obliquity of the rays of the sun on that surface. PROBLEM I. Plate 24. Given the ichnography and elevation of a base and capital, and the seat of the sun's rays on the ichnography, and on the elevation ; to project the shadows caused by the several parts of itself, and the line of shade upon the base. Imagine the object to be sliced, or cut, by as many planes, parallel to the axes of the columns,* and to the sun's rays, as may be thought convenient for the purpose : then it is plain, if a ray of light enter any of those planes, that every part of the ray ^vill be in that plane, and that the projecting parts upon the edges of these planes will withhold the rays from a part of the edge of the plane ; and the lowest point of that part will give the edge or projection of the shadow of the part which throws the shadow : then, if a sufficient number of these points are found, a line drawn through ihern, with a steady hand, will give the shadow ; the line of shade will be found by drawing lines to touch the several sections parallel to the seat of the sun's rays on the elevation ; and a line being drawn through the points of contact of the sections, will give the line of shade. Let H I K be the ichnography of the abacus ; H S K the ichnography of the ovolo ; and M P L that of the astragal ; the lines G Y, F X, E W, D V, C U, B T, and A S are lines drawn parallel to the ichnography, cutting the front I K, of the abacus, and from the seats on the ichnography, and the several seats on the elevation, the shadows may be described, as is shown in the elevation : then lines are drawn to touch the most prominent parts of those sections ; and the places where they cut the other parts of the sections will be the projections of the several points as before, and a line being drawn through these points will give the shadow. The part G F E is the shadow from the abacus, and D C B the shadow from the ovolo ; thus the point g in the elevation is the shadow of P ; / is the shadow of N, and E the shadow of m ; and the shadow of the other part of the abacus would be where the dotted curved line is represented ; but as the sun shines on the ovolo, in the middle of the abacus, it will throw the shadow lower than the dotted lines. This will be found by drawing lines to touch the several sec- tions, which will give the points B, C, D. * It is not absolutely necessary to suppose the plane parallel to the axis of the column, as in this problem ; but the sections formed by planes in this position are more easily found than in any other, for Tvhich reason I prefer the above position of planes. 78 SHADOWS, Note. — That the line of shade on the torus might have been found in a very different manner than is 8ho>vn ia this example, may be seen by the circular ring, plate 19. Much after the same manner may the shadow and lines of shade be found on the attic base, as is shown in plate 24. PEOBLEM II. Plate 35. Fig. 1. To find the shadow of a cylindrical recess in a wall, whose axis is perpendicular to the plane of the wall ; having the seat of the sun's rays on the ichnography and elevation. Let Fig. 1 be the elevation of the wall, and C D the diameter of the cyUndrical recess ; and let E F G H be the ichnography ; bisect C D at a ; draw A a per- pendicular to E H, cutting it at A ; through A draw A B parallel to the seat of the sun's rays on the ich- nography, cutting F G at B ; through B draw B b parallel to A. a; and through a draw a b parallel to the seat on the elevation, cutting B Z> at i ; then on B as a centre, with one half of C D, describe a part of a circle, as is shown by the dark line, and it will be the edge of the shadow. Much in the same manner may the shadow of a recess, which has a back parallel to the plane of the wall, be found, as is shown at Fig. 2. PROBLEM III. Fig. 3. To find the shadow of a recess con- structed as in Fig. 2, when the sides of the ichnography are inclined to the intersection of the two planes of the ichnography and orthography given, the intci-section of a num- ber of planes passing through the luminary perpendicular to the plane of the elevation. Let Z 6, W Y, T V, and Q S be the intersection uf as many planes passing through the sun perpen- dicular to the elevation, and let Q, R be the projec- tion of one of the sun's rays on that plane ; also, let H I be the scat of the sun on the ichnography, cut- ting the back F G of the elevation at I ; from I draw I N perpendicular to I d, the common intersection of the ichnography and orthography; from M, draw M N parallel to Q R, cutting I N at N ; tlu-ough N draw N O parallel to M U ; on O as a centre, and with the distance O N, describe the arc N R, cuttijig the side of the recess at R ; through the points S, V, Y, b, draw S R, V U, Y X, and B a, parallel to I d; and through the points Q, T, W, Z, draw the lines Q R, T V, W X, and Z a, cutting the lines S R, V U, Y X, and B a, at the points U, X, a; then through the points R, U, X, a, draw the curve R U X a, and the line I N R U X a will be the edge of the shadow required. PROBLEM IV. Fig. 4. To find the shadow of a hemisi^here niche ; given the seat and altitude of the sun's rays on the elevation. Let I N, G M, E L, and C O be liiies parallel to the seat of the sun's rays ; and on these hues, as diameters, describe semicircles I K N, G H M, and E F L ; draw the line A B, bisecting O C ; from any of the points C, E, G, I, as C, make the angle O C I) equal to the sun's altitude, cutting the side of the niche at D ; through the other points E, G, I, draw E F, G H, and I K, parallel to C D, cutting the semi- curcles E F G, G H M, and I K N, at the points F H K ; through the points D, F, H, K, draw lines D rf, F /, H //, and K k, perpendicular to the diam- eters, cutting them at the points d, f, h, k; and through the points A k, h, /, d, draw a curve, which will be the edge of one half of the shadow, from which the other half may be drawn, as is shown by the figure ; and this will give the shadow com- plete. OBSERVATIONS. I have given one example of the cflect of light and shade on mouldings of different curvature : I shall endeavor to show the effect of light and shade also on many other examples, especially on the five orders of Architectiue. From what has been said on this subject, many practical and useful rules in shadowing may be de- duced ; but as I have far exceeded the bounds first assigned for this part, I must end with observing, that, from a consideration of the foregoing examples, the shadows of all objects, however complicated, may be found, as every object may be considered as com- pounded of prisms, cylinders, spheres, and annuluses ; F/. y /-/'/J. 1 1 1 1 — y 'i. ^W'*^^ j ^^\ 'v. \ -i Jl .'■>./.-/. /. '" T^Z. I'l ..".) A //I jri.// fj/f^l / J ■4 C %l G T) /■7t/. /. ryii^ • ^ Fur 2. H i> 1 ^ G ' ^ ^ ^// S / y ^/ T, T A' ^\ ^^^.3. X':S. FuUsizc. n .ui .IvV iV^<'.i' SiW>*'ay &f{arrrauf. /)c£- THE ORDERS. 83 To describe an echinus having the depth of the moulding C D, the greatest projection at D, and to be quirked at the top and bottom. Fig. 2, No. 3. Complete the rectangle C B A, and proceed as in plate 6, Geometry. To describe a scotia. Fig. 2, No. 2. Join the ends of each fillet by the right line A B ; bisect A B at D ; through D draw C D E parallel to the fillets, and make C D and D E equal to the depth of the seotia ; then will A B be a diameter of an ellipsis, and C E its conjugate. Pro- ceed as in plate 6, Geometry. How to describe Grecian mouldings, whether elliptical, parabolical, or hyperbolical ; the greatest projection at B being given, and the tangent C F at F, the bottom of the moulding. Fig. 4, Nos. 1, 2, and 3. Draw G F a continuation of the upper side of the under fillet ; through B draw B G perpendicular to B F, cutting it at G, and the tangent F C at the pohit C ; also, through B draw B E parallel to G F ; and through F draw F D E A parallel to G B, cutting B E at E ; make E A equal to E F, E D equal to C G, and join B D ; then divide each of the lines B D and B C into a like number of equal parts ; from the point A., and through the points 1, 2, 3, 4, in B C, draw lines, cutting the former, which will give the points in the curve. If the point C, where the tangent cuts the line B G, be less than one half of B G, from G the moulding will be elliptical, as in Fig. 4, No. 2. K G C be one half of B G, then the moulding is parabolical, as in Fig. 4, No. 1. If G C be gi-eater than half of B G, then the mould- ing is hyperboLieal, as in Fig. 4, No. 3. By this means you may make a moulding to any form you please, whether flat or round. [On plate 30 will be found four designs for archi- traves, for the finish of doors and windows, full size. These are substituted for plates 83 and 84 of the last edition, as being more in keeping with the taste of the times, &c. — Editors.] THE OEDERS. The term order seems to sustain the same relation to architecture that the term harmony does to music, or the ancient term ordonnancc to painting. It is, in fact, no more nor less than an assemblage of parts and mouldings, so disposed as to give an effect at once pleasing to the eye, and proportioned and adapted to the ofiice each has to perform. Vitruvius, who was nearly, if not the first writer on architecture who flourished in the first century after the birth of Christ, expresses the idea as fol- lows : " It is an apt and regular disposition of the members of a work separately, and a comparison of the universal proportion with symmetry." This, in his work, (chapter 2d,) he calls ordonnancc. Scamozzi, the son of an architect, and himself one of the old masters, the rival of Palladio, and who after the death of that artist, in 1580, had no competitor, is, we be- lieve, the first of the ancient \%Titers that has given us what may be termed the description of an order. He observes in his book, (2d chapter, 2d part,) " that it is a kind of excellency which infinitely adds to the shape and beauty of buildings, sacred or profane." He seems to have attempted to convey the same idea as the author before quoted, which idea is compre- hended in the terms propriety and harmony. Having now given the idea which the ancients would seem to have us entertain by the Latin word order, we wUl proceed to illustrate more fully the composition and use of the orders. First, then, an order is composed of two parts, viz., the column and the entablature ; these are again each divided into three other parts, which parts are composed of an assemblage of mould- ings, each respectively proportioned and adapted to the order of which it is a part. The parts of the entab- lature are called the architrave, frieze, and cornice ; those of the column are the base, shaft, and capital, as 84 THE ORDERS. may be seen on plate 50. These are again subdivided into other parts, as will be seen by the description of the respective orders. The species of orders are five in number — the Tuscan, Doric, Ionic, Corin- thian, and Composite ; each is a composition peculiar to itself, and is calculated to produce the expression it is intended to possess, viz., strength, grace, ele- gance, and richness. The orders above named rightly understood, and correctly applied, are the foundation upon which architecture has long rested as an art. The oldest of these is the Doric, the next the Ionic, and the last the Corinthian. The Tuscan is said to have been invented by the inhabitants of Tuscany ; and Vitruvius has first given it a name and placed it in his book, a copy of which is shown on page 31 ; but he docs not inform us of a single building on which it has been employed, and as no examples exist to warrant the belief of its frequent use in his day, we are led to suppose that its rustic plainness did not suit the Roman taste of his time. It has, however, received the approbation of the principal masters who have succeeded him, and is now ranked with the regular orders. The Composite is a Roman invention, and has been termed by Sii' Henry Wotton, in his Parallel of Ancient Architecture with the Mod- ern, the compounded order. It is composed of parts of the other orders, but principally of the Ionic and Corinthian. The proportion of the parts of the or- ders are as various as the examples — no two authors agreeing. In the examples given, the parts are fig- ured, as will be seen ; and the proportion assigned to each, as the example or author has directed explana- tions of the orders more in detail, will be found at- tached to them under their respective heads. — Eds. TUSCAN ORDER. The Komans added the Tuscan, or Etruscan, to the tlncc Grecian orders, as they subsequently did the Composite. The idea of the Tuscan is undoubtedly derived from the Doric order, from ■which it differs, according to the view taken of it by Aldrich, as much as the appearance of an inhabitant of the country does from one of a cit}'. There is extant no ancient specimen of it with an entablature. It is the first of the Italic orders, and is called Tuscan, as having been origi- nally employed by that ancient people, once powerful in Italy. " Vitruvius speaks of it as rustic even to deformit)' ; nor were the later masters more favorable to it, except Palladio." Having no complete exaraide from antique buildings, that which is given in this work is taken from the description by Vitruvius. Plate 31. From Vitruvius, tvith lite Proporlion of the Parts in Numbers. A^'e have no complete example of this order re- maining from antique buildings ; and all that we know of it is from the description by Vitruvius, from which this example is taken, and is, therefore, the only standard. The proportions of the parts are exhibited by equal divisions on the plate. That celebrated building, St. Paul's, Covent Gar- den, is the only true specimen there is of the Tuscan order in England. It may be adapted with great propriety to market-places, as the simplicity of its parts and the extraordinary projection of the cornice render it suitable for that purpose. Fig. 1. Elevation of the order, from Vitruvius. Fig. 2. The ichnography of the mutulcs in the cornice. Fig. 3. Profile of the upper part of the cornice. The column is seven diameters high ; the base and capital are each half a diameter ; the base is divided into two equal parts, one of which is given to the plinth, the other to the torus and fillet ; divide the capital into three equal parts, give one to the hypo- traehelion, one to the ovolo and fillet, and the upper one to the abacus. The mutulcs in the cornice are to project one fourth of the length of the column. Fig. 4. A modern example of the Tuscan order, with the proportional measm'es in numbers. On plate 32, we have given a design for the regu- lar Tuscan order. No example, except that on plate 31, is in any of the previous editions. The design here given is a composition from Chambers and Pal- ladio. In his example of the Tuscan, Chambers has followed Vignola and Serlio, in omitting the break in the architrave, and making it consist of only two members. This, it is acknowledged, is according to the example given us by Vitruvius ; but as liberty has been taken to adapt it to other times, there seems to be no excuse why the method pursued by Palladio should not be entitled to as much attention as that by Vignola. The majority of authors have approved the practice of the former ; in the example we have composed, we have retained the bold and classic pro- portions, as given by Chambers, for the cornice, add- ing to it the architrave by Palladio. The column is according to that given us by Chambers, and it is, we believe, the most approved proportion with which 'vTyi©©iira ®ta©:i[a = Fiyf.i. 140 a 1 SI < I. J Fu,. «. 1 e,!rf7 V 0^' 1 if-jn \ lo i i Fi^. -1. K T s- 2J 777,. c ;2«s "31 JP 1 <^ ,?J) M ^ 1 1 ■V TT^iiSCgAR) ®iS®rsrft II. j:'i y-H /■>,/. / T V III! Ml ! -1 —I . .1 I J 1 — 1 Tiis.-.m Impost - 1 fi ( //'> /■A/. :.' *\ ,vi ) 1 i 1 :u' nr r \iHrr^a^- H- Ifa^Jinyt JJ.J THE ORDERS, 85 we are acquainted. No. 1, on plate 32, is the order figured to a scale of minutes. No. 2 is the impost and archivolt of the same. — Editors. ROMAN DORIC. Some architects have maintained that the Doric order h unfit for sacred edifices, by reason of its irregularity. This opinion was held by Tarchesius, Pytheus, and Ilermogenus. The latter, after having prepared marble materials for building a Doric temple, changed the order, and made it Ionic, dedicating it to Bacchus. The Doric or- der, however, is not deficient in grandeur, but an inconvenience arises in the distribution of the triglyplis and lacunaria ; for it is necessary that the triglyphs should bo placed over the middle quar- ters of the columns, .md the metopes, which are between the tri- glyphs, must be as long as high; also, the triglyphs at the angles are placed at the extremities, and not over the middle of the columns ; therefore, the metopes which are next the angular triglyphs will not be square, but longer by half the breadth of a trigljqih. Some, who wish to make the metopes equal, lessen the extreme inter- columniation by half the breadth of the triglyph. However, the metope or the contracting of the intercolumniatiou is a defect. Though the ancients have been observed to neglect exact regularity in Doric buildmgs, it is shown in its proper place how far we ought to follow our masters. The front of a Doric temple, where the columns are placed, is divided, if it be terastyle, into twen- tj'-eight parts ; if hexastyle, into forty-four. One of these parts will be the module, which, in Greek, is called Embafcs, and by which all the other parts are proportioned. The thickness of the column must be tw^o mod- ules ; the height, with the capital, fourteen ; the height of the capital one module, the breadth two modules and a sixth. The height of the capital is divided into three parts, of which one is given to the abacus, with the cimatium ; another to the echinus, with the annulets ; and the third to the hypotra- chelion. The columns are diminished as described on the plates. The height of the epistilium, with the tenia and drops, is one module. The tenia has the seventh of a module, the length of a gvittse under the tenia coinciding with the perpendicular of the triglyphs. Their height with the regula is one sixth of a module. The breadth of the epistilium also answers to the hypotrachelion of the column. On the epistilium are placed the triglyphs with the metopes, having the height of one module and a half, and the breadth in front one module. They must be so distributed that they may be over the centre of tlie columns at the angles, and two be- tween each column. The breadth of the triglyphs is divided into twelve equal parts, of which tlie breadth of the femur in the middle will be two parts ; then a channel is cut on each side of the femur, the breadth of each channel being equal to two parts. Next to the channels two other femurs are left, one on the right and the other on the left, each equal to the breadth of the middle femur, or two parts ; then a part will remain next to the edge of each triglyph, which is to be cut away in the form of a semi- channel. On either side of this channels are sunk, as if imprinted by the elbow of a square. To the right and left of these another femur is formed. In the same manner, semi-channels must be sunk at the extremities. The triglyphs being thus disposed, the metopes are as high as long; on the angles, also, the semi-metopes are made half a module in width. Thus all the errors arising from the wrong disti-i- bution of the metopes, intcrcolumniations, and lacu- naria will be rectified. The capitals of the triglyphs must have one sixth of a module. On these capitals is placed the coro- na, projecting a half and a sixth part of a modiUe, having a Doric cimatium below, and another above. The corona, with the cimatiums, are half a module in thickness. In the under part of the corona, per- pendicularly over the ti-iglyphs and metopes, the guttse in the mutules are so distributed that there may be six in length, and three in breadth. The spaces between the metopes being rather broader than the triglyphs, are either left plain, or carved ; and at the edge of the corona a channel is cut, called Scotia; all the remainder, as the tympanum, the cima, and corona, are the same as in the Ionic order. Concerning the diminution of the column, accord- ing to Vitruvius, he gave the following rule for all kinds of columns, the Tuscan excepted : — The diminution of the top of the column at the hypoh-achelion is thus regulated : If the column be not less than fifteen feet high, the thickness at the bottom is divided into sis parts, and five of these parts are given as the thickness at the top. " If the height is from fifteen to twenty feet, the bottom of the shaft is divided into six parts and a half, and five and a half of these parts make the 86 THE OKDEKS. thickness of the column at top ; and if from twenty to thirty feet, the bottom is divided into seven parts, and six of these make the diminution at the top. If it is from thirty to forty feet high ; the bottom thickness is divided into seven parts and a half, of which six and a half is the measure of the diminu- tion at the top. If from forty to fifty feet, it is divided into eight parts, whereof seven will make the thickness of the hypotrachelion at the top of the shaft. And if it is still higher, the same propor- tional method is observed ; for, as a greater height causes them to appear more diminished, they are, therefore, to be corrected by an addition of thickness, beauty being the provmcc of the eye, which, if not satisfied by the due proportion and augmentation of the members, con-ccting apparent deficiencies with proper additions, the aspect will appear coarse and displeasing. Plate 33. This plate shows the elevation of the Roman Doric, as given by Palladio. Fig. 1. The elevation. Fig. 2. The cornice inverted. Fig. 3. The capital inverted. Plate 34. Elevation of the Doric Order from the Baths of Bio- clesian, at Rome, with the Proportions in Numbers. The cornice of this example is not Doric ; it is too abundant with mouldings, and overcharged with enrichments. The disposition of the triglyphs and metopes in the fi-ieze is according to the rules of Vitruvius. The capital is not Doric, but of another kind ; nor could this composition be known to have the least resemblance to the Doric order, if the triglyphs in the frieze were omitted. Fig. 1. The elevation of this example. Fig. 2. A section of the column, showing the flutes. ROMAN IONIC, Plate 35, Is the Roman Ionic as approved by Chambers, and is inserted to supply the place of plates 56 and 57 of the previous edition, which contained the example of the Temple of Concord, at Rome. This was a very singular example, which was, perhaps, the best authority the author had for introducing it. The cornice contains mutulcs resembling the Doric, and dentils as in the Ionic. The frieze and archi- trave are plain, with the exception of two breaks, the top one of which contains a cavetto or hol- low. There is no band moulding to separate the firieze from the architrave. The capital is angular, volutcd, and is not without merit ; but the extreme plainness of the space between the cornice and the top of the capital, and the connection between the cornice and frieze, is so inelegant, that the anath- emas of those who would have used it have been called down upon it, and it is now scarcely if ever used. The example given by Chambers is, perhaps, as good as any wc have ; and we have, therefore, in- serted it to complete the Roman orders. Fig. 1 is the order, and figs. 2, 3, and 4 the details of the cap- ital. — Editors. CORINTHIAN ORDER. The Corinthian order took its rise in the flourishing days of Corinth, a celebrated city commanding the communication of the peninsula of Feloponncsus with the continent of Greece. It is generally regarded by writers on architecture as being more delicate than the Ionic, and is thought to resemble the graceful figure of a virgin. Among the ancients, it had much resemblance to the Ionic. According to Vitruvius, it imitated that order in every part but in the capital of the pillar. In the introduction to this work, we have alluded to the pretty Greek story told of the origin of the capital. Villapandus gives another equally dubious account of its origin ; and Aldrich conjectures as more probable that, as the shaft of a pillar represents the trunk of a tree, so the tree being lopped, and sprout- ing again, furnished the hint for the design of this capital. But, however this may be, wc believe it will be generally conceded that, in attempting too much, this order has deviated firom the true sim- plicity of nature. It marked an age of luxury and magnificence, when pomp and splendor had become the predominant passion, but had not yet extinguished the taste for the sublime and beautiful; and in this, attempts were made to unite these characters. DEFINITIONS. 1. An order which has two annular rows of leaves in the capital, each leaf of the upper row growing between those of the lower row, in such a manner that a leaf of the upper row may be in the middle of each side or face of the capital, — and if between Kr.Hii An.liv;! VallMili, ['].3.S 3.i -n~ -31: 23Z J.li "JfT ;) J. # A (1^ rr^r— m /^ i M I 000 000 000 000 5-i 'fi> vy A ra IP ® rs^ n < « „ l-loiM 111, r.Mll,.^ ,,| DicM-lr.si.ln Ml I'.nlii n..;i |iiijiiiimiimuiti^Diiii.ii _ _ .i.ii;iiimniDiiiiui'iiiiijiimi!i^Di]]imimijiiii^iiaiiniijiiiiiiiiiiiimLiuMmiiuii(iwiiitiai))ii.iiiffl^^ i iiaiiiiiiiiiiiiwin~ illiliiiliiliiliiiiiiiiiiiiliiiiililiiS •JlnJ"i|IHl''"n||il|li''i|j|i'ii(iii ' i^i^mnmimim>\'ltfimm\j\Wm^ 2j 321 a? =2Sz 3'f ? i'i tJh ai. itlr|in|ilit|||jl|,l(,(|l'iitr||(iM'i''SSiri''''lirll iilllfwirlll|||||ii|II|||ni|ll||»ui«li|lllliiiil»«l< "1||ii«""' »«""""»™i' ""Ill "i"nraiii|||llliii||»iiii||liiliiiii|,i||llili;||ii. "" ;(i|;i:i' Jlilll'llllil iiiiiu, 'I' "f III! ' !!"|li'l ill i> I IliillllXillllli ij />■-/. :'. -'V P^ .\ ~1- ll(©Kia© (©I^IBLCIS, liiiM l„ Sir Willi..!. I C'h.....l.. IM..>:. VI. M I'liMH ill, I'.in I ll.llll .111.1 llll- 'r.-llll.l.' ..I .lll|MllT ,ll H.ll /■>y J /•la t'^ri. .). i-siiSxcu-jiKi ©©[saiiaviKiiJAM VI. M- I'lom llii- rnrln-ci nl' rhc I'.lli ihi'.ni .11 ,^\\ Fill ■'• m zjss: Kiiun rhi' Arch oC Titn.M :n Ucniic I'l V) m 7T .iff'* ■ui 4^ HsMs mEMms^mmmfsmmmi ^^r WWMMMMMmmOMMM ^ — w it^Mi ^m UUUUUUUUJJUJd '- ^mit:;(i:^mm M^^^mm'S'it^ E2IOE2]EI3EEin23^23SEIIII Jit- Wm^^' ' c:^P 'I ' J THE ORDERS. 87 each space of the upper leaves there spring stalks with volutes, two of which meet at the angles of the abacus, and two in the middle of the capital, either touching or interwoven with each other, — a capital so constructed is called Corinthian. 2. An order wliich has a Corinthian capital, and an Ionic or any other entablature, is called the Corin- thian order. Plate 38. The Corinthian Order, from the Pantheon, at Rome. This example, though plain, is yet beautiful and chaste, and is an excellent model of the order. Fig. 1. Elevation of the order in numbers. Fig. 2. Section of one quarter of the column next the capital ; also a section of one quarter of the col- umn next the base. Fig. Elevation of the base of a larger size. Plate 37. Fig. 1. Is the outline of the leaves and elevation of the capital, from the Pantheon, as shown in plate 38. Fig. 2. The capital inverted, showing an angle of the architrave. Fig. 3. The elevation of a leaf in the same. Fig. 4. The elevation of a leaf in the capital of a column, Ixom the Temple of Jupiter Stator, at Rome. Fig. 5. The side elevation of the modiUion, from the Temple of Jupiter. Fig. 6. The modillion inverted. Plate 36. From the three Columns in the Campo Vaccina, sup- posed to be the Remains of the Temple of Jupiter Stator, at Rome. The engi'aving exhibited in this plate, of that cel- ebrated example of the remains of Jupiter Stator, is as accurate as any yet published: the capital and entablature are restored from the drawings of an artist, who was so obliging as to favor me with sketches of the ornament which he had from the original. The elegance and beauty of the capital, its graceful form, the grandeur and excellent propor- tion of the entablature, wdth the delicacy of the or- nament, render this one of the most complete exam- ples now existing of the Corinthian order. Fiff. 1. Elevation of the order in numbers. Fig. The cornice inverted, showing the enrich- ments of the modillions and mouldings. COMPOSITE ORDER. The second Italian order, and last of the five orders of architec- ture, is the Composite ; which some -writers have divided into three species, or orders. The first, called the Composite, is composed of the Ionic and Corinthian, " which two esliibit more graces in com- bination than either of them would if joined with the Doric. The Composite is more slender than the Corinthian, and more ornamented with sculpture ; if the latter bears any resemblance to a young maid, the former represents an harlot." The second species, as given by Aldiich and Smyth, is " Dorico- lonic ; the only remaining instance of which may be seen at Home, in the ruins of the Temple of Concord. The base of the column is Attico-Ionic, and without a plinth, except in angular pillars. The capital is lonico-Doric, with the volutes projecting, as in the Italian ; the abacus is Corinthian ; the frieze is sculptured, but the larmier is plain. It has a beautiful appearance." The third species of Composite is where the column is of one order, and the entablature of another ; for instance, when the col- umn is Corinthian, and the entablature Doric ; in which case, it would, therefore, be very properly termed Dorico-Corinthian. " This is approved of even by Vitruvius ; and, in fact, was introduced into the Temple of Solomon, whose columns were Corinthian, supporting a Doric entablature." The Romans first introduced the Composite order into their tri- umphal arches, to show their dominion over the people whom they conquered. Of this order we have many examples from the ancients ; but the following is the most celebrated : it is taken from the Arch of Titus, which was executed soon after the destruction of Jerusalem, in order to commemorate that remarkable event. Plate 39. From the Arch of Titus, at Rome. This most beautiful and elegant example is made choice of as the most proper model for this order. TABLE, Showing the relative Proportions of Grecian Doric Columns contained in this Work. Names of Buildings. Colmnns. Capital. Architrave. Frieze, i Cornice. Modules. Min. Minutes. Minutes. Minutes. Minutes. Portico of Philip, K. of Macedon The Temple of Theseus The Temple of Minerva 13 21^ 11 12i 11 4 12 2i 4i 30J. 27^ 21f 20^ 38 50 43i 40 37 44 48 43i 42i 35 25 32 23A 21 A 25 Found in Asia, near the Tem- ( pie of M inerva Polias \ 88 PILASTERS, PILASTERS. Pilasters are, it is believed, a Roman invention, and certainly an improvement. The Greeks cmiiloyed anta; in their temiiles, to re- ceive the architraves -nliere they entered upon the walls of the cell. Tlicsc, though they were, in one direction, of equal diameter with the columns of the front, were in flank extravagantly thin in pro- portion to their height, and neitlier their bases nor capitals bore any resemblance to those of tlie columns they accompanied. The Ro- man artists, disgusted, probably, with the meagre aspect of these antx, and the want of accord in their bases and capitals, substituted pilasters in theii- stead, which, being proportioned and decorated in the same manner mtli the eolumns,-arc certainly more seemly, and preserve the unity of the composition much better. The reader will find some additional, and perhaps not unimportant, remarks iu re- lation to the pilaster in tlie introduction to this work. Pilasters differ from columns in their plan only, whicli is square, while that of the column is round. Their bases, capitals, and entablatures have the same parts, with all the same heights and projections, as those of columns ; and they are distinguished in the same manner, by the names of Tuscan, Doric, Ionic, Corinthian, and Composite. Of the two, the col- umn is doubtless most perfect. Nevertheless, there are occasions in which pilasters may be employed with gi-eat propriety ; and some where they are, on various accounts, even preferable to columns. If we go back to the origin of things, and consider pilasters, cither as representing the ends of partition walls, or trunks of trees reduced to the diameter of the round trunks which they accompany, but left square for greater strength, the reason for dimin- ishing them will, in either case, be strong and evi- dent. It is likewise an error to assert that pilasters are never necessary, but that columns will at all times answer the same end ; for, at the angles of all build- ings, they are evidently necessary, both for solidity and beauty, because the angular support, having a greater weight to bear than any of the rest, ought to be so much the sti-ongcr ; so that its diameter must cither be increased, or its plan altered from a circle to a square. The latter of which is certainly the most reasonable expedient on several accounts, but chiefly as it obviates a very strildng defect, occa- sioned by employing columns at the angles of a building; which is, that the angle of the entablature is left hanging in the air without any support — a sight very disagreeable in some oblique views, and in itself very unsolid. It is indeed customary, in porches and other de- tached compositions, to employ columns at the an- gles ; and it is judicious so to do, for, of two defects, the least is to be prcfeiTcd. Engaged pilasters are employed in churches, gal- leries, halls, and other interior decorations, to save room, for, as they seldom project beyond the solid of the walls more than fifteen minutes of their diameter, they do not occupy near so much space as engaged columns. They are likewise employed in exterior decorations ; sometimes alone, instead of columns, on account of their being less expensive ; at other times they accompany columns, being placed behind them to support the springing of the architi'avcs ; or on the same line with them, to fortify the angles : they may lilcewise be employed instead of columns, detached to form peristyles and porticoes, but there is no instance of this, that I remember, in all the re- mains of antiquity ; neither has any modern archi- tect, I believe, been so destitute of taste as to put it in practice. When pilasters are used alone, as principal in the composition, they should project fifteen minutes of their diameter beyond the walls, which give them a sufficient boldness, and, in the Corinthian and Com- posite orders, is likewise most regular, because the stems of the volutes, and the small leaves in flank of the capital, arc then cut exactly through their mid- dles. But if the cornice of the windows should be continued in the inter-pUaster, as is sometimes usual, or if there should be a cornice to mark the separation between the principal and second story, or large im- posts of arches, the projection must, in such cases, be increased, provided it is not otherwise sufficient to stop the most prominent parts of these decorations ; it being very disagreeable to see several of the upper- most mouldings of an impost or cornice cut away perpendicularly, in order to make room for the pilas- ter, Avhile the cornice or impost on each side projects considerably beyond it. Mutilations are, on all oc- casions, studiously to be avoided, as being destructive of perfection, and strong indications cither of inatten- tion or ignorance in the composer. Where pilasters are placed behind columns, and very near them, they need not project above seven and one half minutes of their diameter, or even less, excepting there should be imposts or continued cor- nices in the inter-pilaster ; in which case, what has been said above must be attended to. But if they PILASTERS. 89 be far behind the columns, as in porticoes, porches, and peristyles, they should project ten minutes of their diameter at least ; and when they are on a line with the columns, their projection is to be regulated by that of the columns ; and, consequently, it can never be less than a semi-diameter, even when the columns are engaged as much as possible. This extraordinary projection, however, will occasion no very great deformity, as the largest apparent breadth of the pilaster will exceed the least only in the ratio of eleven to ten, or thereabouts. But if columns be detached, the angular pilasters should always be coupled with a column, to hide its inner flank ; be- cause the pilasters will otherwise appear dispropor- tionate when seen from the point of view proper for the whole building, especially if the fabric be small and the point of view near. It is sometimes customary to execute pilasters without any diminution. In the antiques there are several instances thereof, as well as of the contrary practice ; and Palladio, Vignola, Inigo Jones, and many of the greatest architects have frequently done so. Nevertheless, it is certain that diminished pilas- ters are, on many accounts, nmch preferable. There is more variety in their form ; their capitals are better proportioned, both in the whole and in their parts, particularly in the Composite and Corinthian orders ; and the irregularities occasioned by the passage of the architraves, from diminished columns to undimin- ished pilasters, are thereby avoided, as are likewise the difficulties of regularly distributing the modil- lions and other parts of the entablature, either when the pilasters are alone or accompanied with columns. Another disagreeable effect of undiminished pilas- ters is likewise obviated by rejecting them. Indeed, I am at a loss to account for it, and it is diametri- cally opposite to a received law in optics. I im- agined it might be the result of some defect in my own sight, till, by inquiry, I found others were af- fected in the same manner. It is this — the top of the shaft always appears broader than the bottom. The shafts of pilasters are sometimes adorned with flutings in the same manner as those of col- umns, the plan of which may be a trifle above a semicircle ; and they must be to the number of seven on each face, which makes them nearly of the same size with those of the columns. The interval between them must be either one third or one fourth of the flute in breadth ; and when the pilaster is 12 placed on the pavement, or liable to be broken by the touch of passengers, the angle may be rounded off", in the form of an astragal ; between which and the adjoining flute there must be a fillet or interval of the same size with the rest, as in the porch of the Pantheon, at Rome. The flutes may, like those of columns, be filled with cablings to one thurd of their height, either plain, and shaped like an astragal, or enriched, according as the rest of the composition is simple or much adorned. Scamozzi is of opinion that there should be no flut- ings on the sides of engaged pilasters, but only in front; and, whenever cornices or imposts are con- tinued home to the pilaster, this should be partic- ularly attended to, that the different mouldings of these members, by entering into the cavities of the flutes, may not be cut off" in irregular and disagreea- ble forms. But if the flanks of the pilasters are en- tirely free, it may be as well to emich them in the same manner as the front, provided the flutes can be so distributed as to have a fillet or interval adjoining to the wall — which is always necessary to mark the true shape of the pilasters distinctly. The capitals of Tuscan or Doric pilasters are pro- filed in the same manner as those of the respective columns; but in the capitals of the other orders, there are some trifling differences to be observed. In the antique Ionic capital, the extraordinary projection of the ovolo makes it necessary either to bend it in- wards considerably towards the extremities, that it may pass behind the volutes, or instead of keeping the volutes flat in front, as they commonly are in the antique, to twist them outwards, till they give room for the passage of the ovolo. Le Clerc thinks the latter of these expedients the best ; and, that the arti- fice may not be too striking, the projection of the ovolo may be considerably diminished, as in plate 56, Fig. 2 ; which, as the moulding can be seen in front only, will occasion no disagreeable effect. The employing half or other parts of pilasters that meet, and, as it were, penetrate each other's inward or outward angles, should, as much as possible, be avoided, because it generally occasions several irreg- ularities in the entablatures, and sometimes in the capital also. Particular care must be taken never to introduce more than one of these breaks in the same place, for more can never be necessary. In many of the churches at Rome we see half a dozen of them together, which produce a long series of undulated 90 ARCADES AND ARCH E S. — PEDESTALS. capitals and bases, and a number of mutilated parts in the entablature, than which nothing can be more confused or disagreeable. ARCADES AND ARCHES. The arch is, without doubt, a Roman invention ; * and from this circumstance the oldest, which is the semicircular, is called the Roman arch. The time of its introduction may be looked upon as a new epoch in the science of architecture, for by this change the Romans succeeded in laying the foundation for a complete revolution of taste and conception. Says Gwilt, in his Encyloptedia of Architecture, " This change, by various steps, led through the basilica to the construction of the extraordinary Gothic cathe- drals of Europe, in its progress opening beauties in the art of which the Greeks had not the remotest conception." The principal feature of the Roman architecture is the use of the arch and circle, each moulding being composed of some portion; while those of the Grecian are composed entirely of sec- tions of the cone. An arcade is a series of arches, separated by one or more columns, with their imposts and piers, and is often one of the most pleasing, as well as imposing, objects which architecture affords ; * We are aware that, -n-ere we to pass oyer this point without al- luding to the discovery of an arch at Thebes, we should not feel warranted in making the above assertion. An account of this arch may be found in "Wilkinson's Customs of the Ancient Egyptians, vol. iii. pp. 221 and 263. To the arch of Thebes Mr. W. assigns the date of 1500 B. C. But as this structure, if one may judge from his delineation, is so purely Roman in its character, its antiquity is doubted by most authors. The arch in the tomb of Saccara is the other to which he alluded, and is from his delineation simply a lining, and is not capable of sustainmg any weight, which is the office of the arch. Mr. Wilkinson assigns as a reason for the Egyptians not using the mode of construction requiring the arch, that there would be difficulty attending the repairing of any accident that might befall it. In regard to this argument, it would seem, at any rate, that, to an engineer who could erect the Pyramid of Cheops, some way would suggest itself for the repairs of a simple arch, had he ever conceived of its construction. lie again speaks of the consequences attending the decay of a single block, &c. In regard to this it is argued, that, in the case alluded to, the balance on the outer side or back of each course would preserve the opening in some form with- out any arch at all. And besides this, when we take into considera- tion the fact that so much time and labor was expended to procure the immense stones for architraves, which could have been avoided in many instances by the use of the arch, it seems that, had it ex- isted in their very midst, some, to say the least, would have ven- tured to use it- — Editohs. and the utility of them in some climates, for shelter from rain and heat, is obvious. We have given, in plate 40, designs for arcades with and without pedes- tals. The proportions are very nearly the same as given by Chambers ; and, as will be seen by exami- nation, they are different in each of the orders. We should have been pleased to have given examples of arcades above arcades ; but our limits would not allow it. We will state here, however, that as in orders above orders the Tuscan invariably stands at the bot- tom, and above it the Doric ; immediately above tlus the Ionic, and next the Corinthian ; and, should the Composite be used, its place is above the Corinthian. The lower diameter of the shaft immediately above the base of each column is of the size of the one next below it at the top just below the capital ; these dimensions will, of course, govern the proportions of the entire order. If the balustrade be used in the openings, it should extend from pier to pier at the side of the column, and its whole height should be the top of the pedestal, the height of the baluster, or its dimension, is the die of the pedestal. The rails above and below them are a continuation of its cor- nice and base. The use of arcades above arcades is pretty generally confined to public buildings, as, among the Romans, to their theatres and amphithea- tres ; they have, however, been much employed in Europe ; and in the magnificent design made by Inigo Jones, for the palace at Whitehall, are to be found some very fine examples. — Editors, PEDESTALS. Most writers consider the pedestal as a necessary part of the order, without which it is not esteemed complete. It is, indeed, a matter of small importance whether it be considered in that light or as a distinct composition. Vitruvius only mentions it as a necessar)- part in the construction of a temple, without signifying that it belongs to the order, or assigning any particular proportions for it, as ho does for the parts of the column and the entablature. But triangular, circular, or polygonal pedestaLs, or such as are swelled and have their die in the form of a baluster, or are surrounded with cinctures, are, in no case, to be made use of in buildings. Such extravagances, though frequent in some foreign countries, are now laid aside wher- ever good taste prevails. A pedestal, like a column or an entablature, is com- posed of three principal parts, which are the base, the body or the die, and the cornice. The die is always ri III # % A 1 % ¥ ! -.- VI'}.: L_ -— '/i-^r - 4 PEDESTALS. 91 nearly of the same figure, being constantly either a cube or a parallclopiped ; but the base and cornice are varied, and adorned with more or less mouldings, according to the simplicity or richness of the compo- sition in which the pedestal is employed. Hence pedestals are, like columns, distinguished by the names of Tuscan, Doric, Ionic, Corinthian, and Com- posite. Some authors are very averse to pedestals, and compare a column raised on a pedestal to a man mounted on stilts, imagining that they were first in- troduced merely through necessity and for want of columns of a sufficient length. It does not seem proper to suppose that they were first introduced merely through want of columns of a sufficient length, since there are many occasions on which they are evidently necessary, and some in which the order, were it not so raised, would lose much of its beautiful appearance. Thus, within our churches, if the columns supporting the vault were placed immediately on the ground, the seats would hide their bases and a good part of the shafts ; and in the theatres of the ancients, if the columns of the scene had been placed immediately on the stage, the actors would have hid a considerable part of them from the audience ; for which reason it was usual to raise them on very high pedestals, as was likewise customary in their triumphal arches ; and in most of their temples the columns were placed on a basement or continued pedestal, so that the whole order might be exposed to view, notwithstanding the crowds of people with which these places were frequently sur- rounded. And the same reason wiU authorize the same practice in our churches, theatres, courts of jus- tice, and other public buildings where crowds fre- quently assemble. And in a second order of arcades there is no avoiding pedestals, as without them it is impossible to give the arches any tolerable proportion. These instances will sufficiently show the necessity of admitting pedestals in decorations of architecture. With regard to the proportion which their height ought to bear to that of the columns they are to sup- port, it is by no means fixed — the ancients and mod- erns, too, having in their own works varied greatly in this respect, and adapted their proportions to the occasion, or to the respective purposes for which the pedestals were intended. Thus, in the amphitheatres of the ancients, the pedestals in the superior orders were generally low, because in the apertures of the arches they served as rails to enclose the portico, and therefore were, for the conveniency of leaning over, made no higher than was necessary to prevent acci- dents ; and the case is the same in most of our mod- ern houses, where the height of the pedestals in the superior orders is generally determined by the sills of the windows. The ancients, in their theatres, made the pedestals in the first order of their scene high, for the reason mentioned in the beginning of this chap- ter ; but the pedestals in the superior orders were very low, their chief use being to raise the columns so as to prevent any part of them from being hid by the projection of the cornice below them ; and thus, on different occasions, they used different proportions, being chiefly guided by necessity in their choice. Nevertheless, writers on architecture have always thought it incumbent upon them to fix a certain de- terminate proportion for the pedestal, as well as for the parts of the order. It would be useless to enu- merate in this place their different opinions ; but I must beg leave to observe that Vignola's method is the only true one. His pedestals are all in the orders of the same height, being one third of the column ; and as their bulk increases or diminishes, of course in the same degree as the diameters of their respec- tive columns do, the character of the order is always preserved, which, according to any other method, is impossible. With regard to the divisions of the pedestals, if the whole height be divided into nine parts, one of them may be given to the height of the cornice, two to the base, and the remaining six to the die ; or if the pedestal is lower than ordinary, its height may be divided into eight parts only, of which one may be given to the cornice, two to the base, and five to the die, as Palladio has done in his Corinthian order, and Perault in aU the orders.* The plan of the die is always made equal to that of the plinth of the column ; the projection of the cornice may be equal to its height ; and the base, being divided into three parts, two of them will be for the height of the plinth, and one for the mould- ings, of which the projection must be somewhat less than the projection of the cornice, so that the whole base may be covered and sheltered by it. These measures are common to aU pedestals ; and in plate 41 there are proper designs for the Tuscan, Ordonnance dcs cinq Especes de Colonnes, 1 Partie, ch. 6 et 7. 92 IMPOSTS. Doric, Ionic, and Corinthian orders, in which the forms and dimensions of the minuter parts are acciuately drawn and figured. With regard to the application of pedestals, it must be observed that when columns are entirely detached, and at a consid- erable distance from the wall, as when they are em- ployed to form porches, peristyles, or porticoes, they should never be placed on detached pedestals, for then they may indeed be compared to men mounted on stilts, as they have a very weak and tottering appearance. The base and cornice of these pedestals must run in a straight line on the outside throughout; but the dies arc made no broader than the plinths of the columns, the interv'als between them being filled with balusters, which is both really and apparently lighter than if the whole pedestal were a continued solid. TABLE, Showing the Height of Pedestals in antique and modem Works in Minutes, each one sixtieth of the Diameter of the Shaft, Doric, . lowic, CoMPOSlTS, {Palladio, Scamozzi ! Temple of Fortuna Virilis, Coliseum, Palladio, Scamozzi, IArcb of Constantine, ... Coliseum, Palladio Scamozzi , ■ Arch of Titus Arch of the Goldsmiths, Palladia Scamozzi, Arch of Sep. Severus, . . 26 30 44 33J 28§ 30 lli 23 23J 30 55 46 33 30 30 Mouldings above Plinth. 14 15 19f 9^ 14* 15 29 11* 14* 15 30 25i 17 15 30| 80 68f 93f 97J 82i 153" 78 93 132J 141 144^ 133 112J- 140^ 20 22| 23^ 17 2U 22^ 29^ 19^ 19 22^ 29 25^ 17 221 29| Total Height 140 136Jj 180f 14U 162J. 150 228 131f 150 200 255 241 200 180 182^ On plate 41 will be found designs for pedestals of the different orders. They are figured by the same scale with which the order should be drawn in which they may be employed. Fig. 2. In this figure is shown the manner of striking or working a raking moulding to fit and mitre with the same on a horizontal line or flank. First divide the width of the moulding into 1, 2, 3, and 4 parts, as in A ; raise a perpendicular line in B, at O ; trace the cur^'e of the moulding from the intersection of 1, 2, 3, 4, on the curve line of the moulding ; draw a, b, c, d, e, f, g, h, at right angles with the perpendicular line O, to the points /;,/, d, b, in the curve or face of the moulding ; transfer to A. a b, c d, ef, g h. In the like manner, the curve at C may be found. All to mitre in their several parts with each other. IMPOSTS. Imposts are explained in the glossary. By some, however, they are called the walls back of the inserted column, rising from the base to the spring line of the arch, and extending on each side of the column about thirty minutes — forming the side of the apertures of doors or mndows, and, when used without the columns, are appropriately termed pilasters. But they are most generally used for those assemblages of moulding which divide the perpendicular part of the wall from the spring line of the arch. In some in- stances regular pilasters are introduced, when the colimin may be termed isolated, as it stands detached from the walls. We find imposts introduced in the Temple of Solomon ; and they are com- mon in Koman edifices ; as in the Arch of Titus, and most of theii other triumphant arches, &c. In most parts of Europe imposts are found, as also in some parts of the United States. The origin of this style of building cannot be clearly traced. However elegant its aspect in many instances may be, it seems now to be giving place to a more magnificent and majestic style of architecture. Where we once saw one range of columns rising above another, each support- ing a distinct entablature, we now find the whole height supplied by one length, thus preserving the principles of good taste. An impost is the capital of a pier or pilaster which receives the arch in the arcades of the Roman order. On plate 42 we have given designs for the different orders, and have figured them to be drawn by the same scale of minutes with which the order is drawn to which they may be applied. No. 4 is from a de- sign by Vignola ; the rest are by Sir William Cham- bers. Bases. — No. 1 is the Tuscan base ; No. 2 is the Doric; and No. 3 is the Attic. The last named Chambers has used with all his orders, excepting the Tuscan. This base was used by the ancients to a great extent; and they have not, to say the least, in many instances made any improvement — Editors. I'l I. !■ Jl /. 4h " A 1 ?:; / 1-'*- ti J ^^ i^ ■J /i -\ ..■^- h> t'^ 1 l, J' J'4. ti/s i // \:-M ■ vS ;^ T J II I'A a to^ 4,"^!]. •'^^^^^SS^^^^^ D "^^^^i^jT^ "I — -v" ^ ^ Conn tin, -111 and Cnnin nstlc ^4| .T^ I .'> ^^^sxivj^ j:a:y^>3t^ t',.IIMlln;MI l.v \'|.. ,,„!.. (>'■ inllii.iii. ' %r>t wvj/ri'i^ •r p u II II 1 1 1 1 ,1 J .\„.l 1 .Mli 1' 1! "S li> io ) It' /./ X,..^' U! Tuscan ll.u 11. ;ili.l I. I' lil.MI I (' .1(1 ^ HI ~J "^ TZ^lL -j^ JV'./ —^. ,J \,.„.. 1 1 1 f" V / ^ _.,.__.;' ["'"■ \ I 1 .^ .i;...-' ; i'ii :^~7 r — r"^ M \ A'r'..i I .''/// . I /■? ^ I 'oriviO 11)111 . s y / . X,:/.- .i;..- 'I'usc an. ' :■/ III ''- 1_- / ■ /,.'; . J .!>■./ IJaliisirade - y r ^1 rt" BALUSTRADES. 98 BALUSTRADES. The baluster is not found in the works of the an- cients, but owes its origin to the restoration of the art in Italy. It, like the column, consists of the cap- ital, shaft, and base. The most ancient examples were of the shape of a stunted column, and not un- frequently were crowned with a disproportioned Ionic capital. Many forms have been given to them by the later masters, and we may safely say that the invention is one of the most useful as well as orna- mental that was produced by the Italians. A balus- trade is a series of balusters standing upon a base, and croAvned with a capital or rail, — this capital and base being of the same outline in its detail as those of the pedestal which accompany them. It is proposed by Blondel that balusters and balustrades should partake of the character of the edifice they are to be employed upon ; and by some their species has been so arranged as to appropriate a design to each order, and in the works of such they are known by the name of Tuscan, &c. The general riUes to be observed in the construction of balustrades are, that the balusters be of an odd number, and the dis- tance between them equal to half their larger diam- eter, which will produce an equality between the open and solid spaces ; and a half baluster should always be placed against the pedestal. When the balustrade is formed without pedestals, as is often the case where balusters are placed between columns, the half baluster may be omitted. The pedestals of balustrades should always be placed directly over the column, and the die be of the same width as the di- ameter of the column at the top. Where the columns stand together as in what is termed coupled columns, as seen at A, in plate 43, the pedestal should extend over both entire. Also, where a balustrade terminates against a roof or pediment, the termination should be by a pedestal, and it should commence where the balustrade begins to diminish, be the distance more or less ; and in no case should the baluster be cut to the roof. The pedestals, as before stated, should stand directly over the columns, — the distances be- tAveen them would, of course, depend upon the in- tercolumniation, — but where no columns are used, either seven or nine whole balusters, with the half ones, have been recommended as producing the best efiect ; for when the pedestals stand too near each other, they present a heavy and clumsy appearance to the work ; and where they are too far apart, the work will appear weak. The bulbs or bellies of balusters are often enriched ; which, for stairs and highly-finished interiors, is quite requisite. In regard to the heights of balustrades, when they are used as a protection to terraces, or before windows, they should be not less than two feet six inches, nor more than three feet high ; but when they are used as merely ornamental appendages to a building, they should be, according to the majority of authors, not more than two thirds of the height of the entablature over which they stand, nor less than two thirds, without count- ing the plinth, the height of which must be sufii- cient to leave the entire baluster exposed to view from the best point of sight for viewing the building. Palladio has, however, in some instances, made the balustrade the height of the entire entablature, as at the Valmarana Palace. Inigo Jones has, in some instances, followed his example ; but this was not the usual practice of either. We have before stated, that the moderns have given to the baluster a variety of shapes. On plate 43 we have given the designs recommended by Chambers, with the method of pro* portioning them, in the manner adopted by him. No. 1 is the Tuscan ; No. 2 the Doric and Ionic ; No. 3 the Corinthian and Composite. No. 4 is a design for a Tuscan baluster, and has generally been executed square. Nos. 5, 6, and 7 are designs for double-bellied balusters, and are intended principally for balconies and terraces, the rail and pedestal being the same height as in other designs. Chambers has designated them respectively the Tuscan, Doric, and Ionic and Corinthian. The method of proportioning them to the order is as follows : After ascertaining the height, as before directed, divide it into thirteen parts ; of which, give two to the rail, eight to the baluster, and the remaining three to the base : if the baluster is required to be less, divide the height into fourteen parts, giving two to the rail, eight to the baluster, and four to the base. One of these parts is a module for determining the rest, and is divided into nine other parts, called minutes. From what has been said, the whole on plate 43 will, without doubt, be clearly understood. — Editors. 94: GRECIAN ORDERS. GRECIAN ORDERS. The Doric, the Ionic, and the Corinthian were the only orders of architecture employed by the Greeks. The Tuscan and Composite were used only in Italy — the one more rude, the other more orna- mented, than the Greek orders, -which occupied a middle rank. To attain, therefore, a proper knowledge of the true principles of archi- tecture, the student shoiJd devote most of his attention to the three Greek orders ; not only because in them these principles arc the most displayed, but because of all the monuments of antiquity which have subsisted to modem times few, or perhaps none, can be pointed out ra which the Roman or Italic mode of construction is certainly to be traced. DEFINITIONS. 1. If any number of frustums of cones, or frus- tums of conoids of similar solids and equal magni- tudes with each other, be so arranged that their bases, which are the thickest ends of the frustums, may stand upon or in the same horizontal plane, and their axes in the same plane with each other and perpendicular to the horizon ; and if on the tops of these frustums be laid a continued beam ; and if over this beam be laid the ends of a number of equi- distant joists, the other ends being either supported in the same manner, or by a wall or any piece of build- ing whatever, so that the upper and under surfaces may be in the same horizontal planes ; and if over the ends of these beams be laid another beam paral- lel to the former, which lays upon the fr-ustums, but projecting farther out from the axis of the columns than the vertical face of the lower beam which is over the frustums ; and if this beam supports the ends of rafters whose upper surfaces lay in the same inclined plane, so as to support a covering or roof, — the whole of this mass, together with the frustums supporting it, is called an order. 2. K the bottom or lower end of the frustum finish with an assemblage of mouldings, projecting equally aU round beyond the bottom of the frustum, then this assemblage is called a base. 3. If the upper end of the frustum finish with mouldings or any kind of ornaments, and if these ornaments or mouldings be covered with a solid, whose upper end and lower sides are square, and the vertical or perpendicular sides rectangles, then this solid, together with the ornaments or mouldings under it, is called a capital. 4. If the frustum has no base, then the capital and frustum together are called a frustum column ; but if the frustum has a base, then the base, frus- tum, and capital, taken together, are simply called a column. 5. The mass supported by the columns is called an entablature. 6. The under beam of the entablature is called an architrave or epistylium. I. The space comprehended bet^veen the upper side of the epistylium or architrave and the under edge of the beam over the joists, is called the frieze or zophorus. 8. The edge or profile of the inclined roof sup- ported by the joists or cross beams, jetting out be- yond the face of the zophorus or frieze, is called a cornice. 9. The lowest or thickest part of a column is called the diameter of the coluinn. 10. Half of the diameter of the column is called a module. II. If a module be divided into thirty, or any other number of equal parts, then these parts are called minutes. 12. The shortest distance from the bottom of the frustum of one column to the bottom of the frus- tum of the next column is called the intercolumni- ation. 13. When the ijitercolumniation is one diameter and half a column, it is called pijcnostyle, or col- timns thick set. 14. When the intercolumniation has two diam- eters of the columns, then it is called si/style. 15. When the space bct^-een the columns is two diameters and a quarter, then the intercolumniation is called evstyle. 16. When the intercolumniation is three diam- eters of the columns, then it is called decastyle. 17. When the distance betw'een the columns has four diameters of the columns, then that intercolum- niation is called arccostyle, or columns thin set. 18. When there are four columns in one row, then that number is called tetrastyle. 19. When there are six columns in ojic row, then it is called hexastyle. 20. Wlicn there are eight columns in one row, then it is called octastyle. GRECIAN DORIC. 95 GRECIAN DORIC. The first Grecian order in point of antiquity is the Doric, so called from the Dores, a small tribe in Greece ; or, as some say, from Dorus, an Achaian chief, who first employed the order in erecting a temple to Juno, at Argos. DEFINITIONS. 1. If through the axis of the shaft be supposed to pass twenty vertical planes, making equal angles with each other, which wiU cut the surface of the column in twenty places ; and if the surface of the column be curved or hoUowcd between each two lines, from the bottom to the top of the shaft, ter- minating immediately under the lowest annulet, — then the shaft will have twenty curved sides, and as many angles ; and if nearly at the upper end of the shaft be cut one or more grooves, of an equal depth from the surface of the hollowing, each groove being parallel to the annulets under the echinus, then a column so formed is called Doric. 2. That part of the column contained between the upper channel and the lower annulets is called the hypotrachelion, neck, or frieze of the capital. 3. That part of the Doric column comprehending the abacus, echinus, annulets, and hypotrachelion, is called a Doric capital. 4. If the ends of the cross beams in the frieze which lay upon the architrave be at right angles to the sides of the beams, and parallel to the front or the architrave ; and if the two vertical right angles of each beam formed by the two vertical sides and the ends be cut away by vertical planes, making equal angles wath the sides and ends, — that is, 135 degrees with each, — and if two other vertical chan- nels are cut on the end, so that the planes, which are three in number, left on the ends of each beam, may be equal rectangles, and the two sides of each chan- nel make 135 degrees with the ends of the joists, and are so disposed that there may be a rectangle next to each semi-channel, and then two whole channels, leaving a rectangle in the middle, — the end of the beam so formed is called a trigli/pk. 5. K the spaces between the triglyph be filled up with planes parallel to the front of the triglyphs or to the front of the architrave ; and if these planes be in the same plane with each other and recessed beyond the ends of the triglypn, so as to show a small part of the vertical sides of the beams, — that is, to be farther in than the channels of the triglyph, — then these spaces so filled up are called metopes. 6. If the front of the beam which supports the rafters that lay upon the joists projects at some dis- tance beyond the face of the triglyph, the plane of the front being parallel to the ends of the beam ; and if a recess be cut from this beam directly over the metopes, the plane of the front of the recess being parallel to, and having a small projecture over, the metopes, and the ends of the recesses over the metopes be in the same plane with the vertical sides of the beam, — then that part of the front of the beam over the triglyph is called the capital of the triglyph. 7. The whole face of the work comprehended between the upper edge of the beam which forms the capital of the triglyphs, and the lower end of the triglyphs and metopes, is called a Doric frieze. 8. If from the top of the architrave project a fillet whose upper edge is in the same plane with the top of the architrave or the lower end of the trigljrph, the front of the fillet being a vertical plane parallel to the front of tlie architrave, having a small projec- ture beyond the front of the triglyph, this fillet being supposed to be continued the whole length of the architrave, and returning in the same manner round its ends ; and if fillets be placed under this fillet, whose fironts stand a little within the firont of the upper fillet, but projecting beyond the face of the architrave and the ends of these fillets, in the same plane with the sides of the triglyph, and, conse- quently, each fillet equal in length to the breadth of the triglyph ; and if under each of these fillets be fixed six equal similar finistums of cones, at equal distances from each other, whose axes are perpen- dicular to the horizon, and the same distance from the face of the architrave, so that the extremities of these frustums may not reach beyond the perpen- dicular of the ends of the fillets above them, — then the front of the architrave so formed is called a Doric architrave. 9. The upper fillet of the Doric architrave is called a tenia. 10. The fillets under the tenia of the Doric archi- trave are each of them called a regula. 11. The little conical finistums under each regula are called guttce, or drops. 96 GRECIAN DORIC. 12. The plain part of the architrave under the tenia and regute is called /acia. 13. If over the capitals of the triglyph be laid another beam, whose front is parallel to the metopes or to the front of the triglyphs in the frieze, having a small projecture from the front of the metopes ; and if over this beam be laid the ends of the rafters which support the covering, the ends having a pro- jecture forward and parallel to the beam under them, one rafter over each triglyph, and also one over every metope, placed directly in the middle of each ; that is to say, a vertical plane perpendicular through the middle of every metope, and also through the middle of every triglyph, would pass through the ends of all the rafters, and divide them into two equal rectan- gles ; and if over the rafters be laid a beam, the front of which, being a plane parallel to the ends of the rafters, has a projectiire ; and if the void spaces be- tween each two rafters and the under side of the beam above the rafters and the upper side of the beam below the rafters be covered in, so that the front of the spaces so covered may be in the same vertical plane with the face of the beam under the rafters, — then those ends of the rafters projecting over the face of the beam under them are called mutules. 14. If to the under side of the mutules be hung three rows of small conical frustums, of the same size as those under the regula; of the architrave, so that there may be six in length in each of the rows, and three in width, then these conical frustums are also called gutta;, or drops, as those in the archi- trave. 15. The front of the beam lying over the mutules is called corona, or drip, or larmier. 16. The under side of the beam lying over the mutules is called soffit, or lacunar. 17. A building, whether of wood or stone, or any other material, having columns supporting an entab- lature over them, as described in the preceding defi- nitions, — such a building, so constructed, is said to be of the Doric order. Having defined the principal parts of this order, it may not be improper to observe that the Doric order lias, in general, more mouldings in the cornice ; but ;is these vary in different buildings, and as the mem- bers already described form its most striking features, i, would have been useless to have taken any ac- i;,;int of them in the definitions. PROBLEM I To draw the elevation of a Grecian Doric order. Make the lower diameter of the shaft of the col- umn one eighth of the entire heiglit of the order; divide the diameter of the column into two equal parts ; then one of these parts is a module ; divide the module into thirty equal parts, and each of these parts will be a minute ; make the height of the col- umn twelve modules, the height of the capital one module ; divide the height of the capital into five equal parts ; give one to the hypotrachelion, and two parts to the annulets and echinus ; make the annu- lets one quarter of the echinus, and the remaining two parts to the abacus ; make the upper diameter of the shaft three quarters of the lower diameter of the shaft, the length of each side of the abacus two modules and one fifth, or two modules and twelve minutes ; the height of the entablature will be four modules, of which the height of the cornice will have one module, and the frieze and architrave each forty -five minutes, or one module and a half; divide the height of the frieze into eight parts ; give the upper one to the capital of the triglyph, and the three lower for the channels ; make one edge of the triglyph in the columns at the angles of the building, directly over the axis of the column, the breadth of the triglyph tAventy-eight minutes, having the other edge of the triglyph dncctly at the angle of the building ; and make the distance between the triglyph, or width of the metopes, equal to the height of the frieze, forty-two minutes ; place all the col- umns between the two extreme ones directly under the middle of the triglyphs. Make the height of the tenia one tenth of the height of the epistilium ; and the height of the regula, together with tlic guttae, equal to the height of the tenia. The height of the cornice being one module, make tlie height of the small bead on the lower part of the cornice one min- ute ; the height of the mutules, including the guttse, four minutes and a half; the length of tlie mutules equal to the breadth of the triglyplis, and their pro- jection beyond the faces of the triglyphs two thuds of their length, observing that one should be directly over the middle of every triglyph, and one over the mid- dle of every metope ; make a fillet above the mutules I'l II ImoIM 111, Tl'TlLI.!.' r.r Min.'HM ,ll ,\lll isl JlliHIIJIESIIC'llHIlMll .'.?* 1 /wV i*tP««fBffifff||^^^^^^^^^^^^^^ '!l'. ■ I .'1- ■vT" - ^ O a U U UJ ' LJ LJ 1-1 LJ LJLl' . "XTC r- n I'P- ^t^^rrv^ Ti^Trm- n I'l 1 ! , 1 ' 1 1 1 />,r3' Sliilllll!lIilll!!li:illllllililiCIEB!llli™t2i»l[llJai''™!?i«SIIIIill»l^ mmWS. 1111(11 ; lllHli ,11,11 I'l.ll /;./. / O o o o o ^> z o o o o o o o o o o o o o o o o o! (o o V-^^ii ) ^^ u O = — ^Jl /;■., :' I, I),/. .?. J ": \ lJ_ 'I I. i? M lY,.in ill,, •(■fuinl, ,.l lli,-»rus ,11 .\iIm r,i Ih. ficf. I \ _)-LJ J -T_r-i_J-\ — r* 3 JO la //'/ 3I!j I I 31 Xt'fi 2i^ *"'s o o o o o o o o c o o o o o o o o o o o oooooo \. //./ .2 o o o o o o \v oooooo \ GRECIAN DORIC. 97 one minute and a half higli, to project beyond the mutules half a minute over this fillet; make the height of the corona one third of a module, or ten minutes, having a projccture over the fillet one min- ute ; make the height of the small echinus one min- ute and a quarter ; over the echinus make a fillet of the same height ; over the fillet make another echi- nus six minutes and a half high, and two minutes will remain for the height of the fillet above the echini;.-?. In order to establish the proportions and true taste of the original Doric order, the following examples are taken from the most celebrated biiildings now remaining of this order. The module is divided into thirty parts, or minutes ; the measures are all num- bered in these parts ; the projections are reckoned from a line representing the axis of the column, and are figured at the extremities of each member. Plate 44. ELEVATION- OF THE DORIC ORDER ON THE TEMPLE OF MINERVA, AT ATHENS, CALLED RARTHENON. This temple, dedicated to Minerva, the chief god- dess of the Athenians, is the most beautiful piece of antiquity remaining. It was built by Pericles, who employed Ictimus and Callicrates for his architects. The entablature is charged with historical figures of admirable workmanship ; the figures of the pediment, though seen at so gi-eat a height, appear to be as large as life, being in alto rilicvo, and well executed ; the figure in the middle seems to have been made for Jupiter, its right arm being broken off, which prob- ably held the thunder. It is likely that between his legs was placed the eagle ; for the beard, and majesty, and expression of his countenance, and the figiu-e being naked, as he was usually represented by the Greeks, sufficiently show it to have been made for Jupiter. At his right hand is another figure, covered half way down the legs, coming towards him, which perhaps was a Victory, leading the horses of INIiner- va's triumphal chariot, which follows it. The horses are finished with great art ; the vigor and spirit pe- culiar to those animals seem here to receive addition, as if inspired by the goddess they chew. Minerva, in the chariot, is represented as the goddess of learning rather than of war, without helmet, buckler, or a Me- dusa's head on her breast, as Pausanias describes her image within the temple. Behind her is another 13 figure of a woman sitting. The next two figures in the corner are the Emperor Hadrian, and his empress Sabina. On the left hand of Jupiter are five or six figures, which appear to be an assembly of the gods, where Jupiter introduces Minerva, and acknowledges her his daughter. The pediment at the other end of the temple was adorned with figures, expressing Minerva's contest with Neptune about who should name the city of Athens, of which there only remains a part of a sea horse. The frieze is charged with basso rilievos, of excel- lent workmanship, on which are represented the bat- tles of the Athenians with the Centaurs ; these appear to be as old as the temple itself. Within the portico on high, and on the outside of the cella of the temple, is another border of basso rilievos around it, at least on the north and south sides of it, which is without doubt as ancient as the temple, and of admirable workmanship, but not in so high a rilievo as the other. On it are represented sacrifices, processions, and other ceremonies of the heathen worship. This temple is now turned into a Turkish mosque. Fig. 1. Elevation of the Doric order ; the propor- tions of the parts m numbers. Fig. 2 is a design, showing the order, with the col- umn and entablature entire. Plate 45. Fig. 1. This example shows the return of the flank at the angle of the building. The figm-es in the metope are omitted. Figs. 2 and 3 show the forms of the moulding and upper part of the cornice. Fig. 4. Elevation of the capital, and of striking the ovolo by conic sections. Fig. 5. Section of one half the column. Fig. 6. Section tlu'ough the annulets, of a large size. Fig. 7. Plan of the soffit inverted. Plate 46. ELEVATION OF THE DORIC ORDER ON THE TEMPLE OF THESEUS, AT ATHENS. This temple is one of the most ancient examples of the Doric order now existing ; it was erected about ten years after the battle of Salamis, by Cimon, the son of Miltiades. The ceiling of the porch is re- 98 GRECIAN IONIC. markable for its construction ; there are great beams of marble, the upper sides of which are level with the bed of the cornice, and the ends corresponding ex- actly to the triglyphs in the frieze, which give the idea of the disposition of the timbers which were first used in buildings, and from which the Doric order is said to have had its origin. This buUding is adorned with beautiful sculpture ; the metopes of the frieze are charged with historical figures, on which are represented various exploits of Theseus ; the battle he had with Sinis, the notorious robber, who dwelt in the Isthmus of Corinth. The- seus is represented making Sinis undergo those tor- ments which he had inflicted on others. In the basso rilievo is represented a man taking hold of another by his middle, and endeavoring to throw him down ; this is, doubtless, intended to rep- resent Theseus throwing Sch-on from a rock; the combat of Theseus with the wild sow of Crommyon, which was killed by that hero. In another basso rilievo is represented a man presenting his hand to a woman, perhaps to express the rape of Ai-iana, or Helen, by Theseus. Some others of the basso rilievos in the metopes are less distinguished. The two mentioned by Pau- sanius arc still to be seen on the front of the temple ; one represents the battle of the Athenians with the Amazons, the other the dispute of the Centam-s and the Lapithw, in which Theseus kills a Centaur with his own hand. The first seems to represent the instant when the Athenians granted peace to the Amazons, for there the women are represented as sitting. The inside of the temple is not ornamented like the outside. This temple is now a Greek church, dedicated to St. George, and is at present in high esteem among the Athenians. Fig. 1. The elevation of the order, with the heights and projections of the members in numbers. The figures in the metopes are omitted. Fig. 2. Represents the ovolo above the facia of the cornice. Fig. 3. Plan of the sofilt inverted. Fig. 4. Plan of the ovolos and annulets of the column. Fiff. 5. Section of one half of the column. Plate 47. ELEVATION OF A URECIAX DOHIC, OF A LIGHTER PUOrOKTIOX THAN ANY OF THE I'KECEDIXG, WITU THE PIlOrORTIOXAL MEASURES IX NUMBERS. The ratio of the parts of this elevation is the same as that on the portico of Philip, King of Macedon, in the Island of Delos ; but the profile of the cornice diflcrs as follows : Instead of the ovolo, which I have introduced in this example, a cima recta in the origi- nal occupies its place ; and instead of the next ovolo under the fillet in this, there is in the original a cima rcversa. The profile in this plate I conceive to be more beautiful than the original, as it will produce a greater variety of light and shade, and, consequently, the mouldings will be more clearly defined ; but as the reader may be desirous of a knowledge of the true form and taste of the original mouldings, I have shown them in Fig. 3. Fig. 1. Elevation, with the jiroportional measures in numbers. Fig. 2. A section through the upp er part of the cornice, showing the form and taste of the mouldings inti'oduccd into this elevation, by P. Nicholson. Fig. 4. A section of the anta3 of the same portico. Plate 48. FROM THE CHGRAGIC MONUMENT OF THRASYLLUS. Fig. 1. The proportional measm-es in irumber. Fig. 2. Section through the cornice. Fig. 3. Section throvigh the capital. GRECIAN IONIC. Plate 49. THE IONIC TEMPLE. Fig. 1. A grouml plan of the Temple on the Ilissu.'!, irith a por- tico at each end. The colums G G are wanting ; but in the place •where they stood circles are marked on the pavement, which are exactly of the same dimensions with the remaining columns, and were evidently designed as an accurate guide to the workmen, when they erected those columns which are now destroyed ; for wliich reason it was thought necessary to make these circles like\rise on the plan which is here given. The capitals of the antip, belonging to the posticus or back front, remain entire, and are of the same form and dimensions with those of the portico, except only that the sides contiguous to the hack wall of the cell are but half so broad as the faces next to the columns ; whereas, in the antce oi the por- I'l i; IV.ini ill.- I'.Hlir,, ,,|- l'lllli|i Kiiuj-,,r M;,, ,-,l,,M /• a. s& -»J3 TIT 35" ih 2ih s:. Fi,,. I. n n I I . I n I 1 1 M I , I I , ■ , I , I w 1 1 i , . I I I I I I ■ . I 1^ =^ /•;,/.:;. -XV' rn,. ./. I'Vniii llir ('hor;li''lc Moll inni'iir iiI' I'liiasNl I'l. I," IL ■JO I ■ :225 Jty.2. S\ /■'if/ ■>. I'M! tu ':. ff.i. I 1-^- *a« -2- ■*-«»*-* i^o-V., >f.'\ I'1.."H1 IVciii III.' luiur l\iii|.l. ..II Ih.' IllssUM H V_ Pl.ol I'lhii ill,- l,,m. T, 1111,1. ,.n 111, 1 ivi 1 lllsus /■/r/ ,' J® MO© I'Viiiu till' 'I\-iM[ilr nl" Miini\ ;i l'iili:i>. al I'l" I'l. P u Fia ; 1 s Fio 3. VLJ GRECIAN IONIC. 99 tico, the sides next tlie pronaos and the faces next the columns are equal. The architraves of the back front project considerably beyond the ant;c, and there arc sufficient remains of them to show exactly how far the columns of the back front were distant from the back wall of the cell. Fig. 2. The elevation of the south side of the temple. Note. — The ground plan and elevation are here given as meas- ured by Stuart and Ilcvctt, in feet, inches, and decimals. It has been already observed, in the general definitions of the orders, that every order consists of a column and an entablature ; that every column consists of a base, a shaft, and a capital, except in the Doric, where the base is omitted ; that every entablature con- sists of an architrave, a frieze, and a cornice ; that the base, shaft, capital, architrave, frieze, and cornice are the principal members of an order ; and that the peculiar mode or form of the members de- termines the particular name of the order. But since many of the mouldings are common to all the orders, and are generated in a similar manner, what has been said in the general definition, and also on the Doric order, will render it unnecessary to repeat the same things in the Ionic, as such mo\ildings cannot form any partic- ular feature of any particular order. It is therefore sho\vn, in the subjoined definitions, how these members ought to be modified, so that they may constitute the Ionic order. DEFINITIONS. 1. If from the under side of the abacus of an or- der there project two or more sphals on each end of the fi'ont, in a plane, parallel to the frieze, so that the extremity of each shall be at the same distance from the axis of the column, and also two others upon the opposite side of the abacus, parallel to the former and projecting the same distance from the axis of the column, so that each of the spirals shall have the same number of revolutions, and equal and similar to each other, the projecting part contained between any two spirals is called a volute. 2. An order which has volutes and mouldmgs in the capital of the annular kind, and the ichnogi-aphy of the abacus square, as in the Doric order, the archi- trave finishing of plain facia?, and mouldings either plain or enriched, the frieze a plain surface, the cor- nice to consist of a cima recta, then a fiJlet and an echinus only ; and if to the under side of the corona are hung a row of equal and similar parallclopipeds, equidistant from each other, whose fronts arc in a plane parallel to the plane of the frieze, then each of these parallclopipeds is called a dentil. 3. An order so constructed is similar to that in- vented by the lonians, and, consequently, is the Ionic order. Plate 30. FROM THE IONIC TEMPLE ON THE lUYER ILISSUS, AT ATHENS. The simplicity and greatness of the parts, their judicious arrangement, the beautiful turning on the volutes, and the graceful curve of the hem hanging between tliem, render this one of the most beautiful and bold examples of this order. The elegant base of the column, the grand propor- tion of the entablature, the massy mouldings of the cornice, and the spacious surface of the frieze, well adapted for sculptured ornaments, and the architrave for its strength, as it is not broken in two or more facia;, arc considerations which shoidd recommend this example. Fig. 1. The elevation of the order and details fig- ured in proportional parts for practice. Fig. 2. A drawing of the order, by dividing the whole height into twenty-one parts, which are dis- posed of in modules and mmutes, as shown in the example ; one of the parts makes a module, or thirty minutes. Fig. 3 shows how to form the curve of the fluting ; the Grecians used the ellipsis form, while the Ro- mans as uniformly made use of a semicucle, as in Fig. 4. Fig. 4. Explained the same as Fig. 3, in plate 58. Fi£ Plate 51. 1. The capital inverted, of the different tastes of forming the volutes. Fig. 2. The elevation of the same. Plate 52. FROM THE TEMPLE OF mXERVA POLIAS, AT PRIENE, IX IONIA. The small projection of the cima recta, and its great height, is of itself beautiful and well contrived for the ornament, as it is less obsciircd by the shadow from the concave and convex parts of the moulding. This small projecture is also well adapted for a low corona ; for the greater the projecture of the cima recta, the more it will predominate over the corona, by the principles of optics ; and, on the contrary, the less the projecture of the cima recta, the less it will predommate over the corona. It follows, therefore, that a low corona wiU require a cima recta of a 100 GRECIAN IONIC. small projccture; but a gi-eater height of the corona will require a greater projecture of the cima recta, and a less height. The dentils, which are a striking feature in this order, show here to very great advan- tage, their bold and singular projecture greatly reliev- ing tlicm from each other. The architrave is well proportioned to itself, and also to the cornice ; the capital is elegant, and the spirals of the volutes arc beautifully drawn. The surprising delicacy of the ornaments, and thck bold relief, with the grand ratio of the parts and mouldings to each other, I'cnder this one of the most beautiful examples of the Ionic order. Fig. 1. The elevation of this example, the propor- tional measures in numbers. Fig. 2. Ichnography of the dentils. Fig. 3. Profile of the mouldings in the base to a larger size. The cimatium, or crown of the arcliiti-ave, was taken from the designs of Mr. Wood, who visited this temple before Mr. Revett. The base of the column is true Ionic : it has no plinth ; the upper scotia is inverted, which diversifies and gives the contoiu* a greater beauty than is the Vitruvian base, in which the scotiaj are one over the other, uninvertcd. The torus is elli2:)tical, and fluted. The eyes of the volutes are bored two inches and a half deep ; the hem, or border, with its fillets rest- ing on the echinus, and connecting with a gi-aceful curve the spirals of the volutes, seeming to keep them secure in their place, adds greatly to the beauty of this capital. Plate 53. FROM THE TEMPLE OF MINERVA POLIAS, AT RRIENE. Fig. 1. Section through the cornice of the pediment. Fig. 2. Front of tlie cornice, showing the orna- ments on the mouldings. It is remarkable, that the enrichment of the upper moulding dificrs from that on the lateral cornice. Fig. 3. The mouldings of the capital, with then- proportion in numbers. Fig. 4. Volute, with the measure in feet, inches, and tenths. Fig. 5. A section through the upper torus of the base, which is of an elliptical form, the transverse axis being inclined to the plane of the horizon. Plate 54. FROM THE SAME TEMPLE. Fig. 1. The elevation of the front of the capital, to larger size. Fig. 2. The ichnography of half of the capital. Fig. 3. Side elevation of the same. Plate 55. FROM THE TEMPLE OF BACCHUS, AT TEOS, IN IONIA. This temple was first begun of the Doric order, by Hermogenus ; but afterwards he changed it into the Ionic, and dedicated it to Bacchus. This example is drawn from accurate measures, taken from that celebrated building. The dentils, in the cornice, add gi-catly to the char- acter of the order. Fig. 1. The elevation of the order. It may here be observed, that no measiues have been taken of the parts which are marked in this example with letters, as none of them could be found. They arc here supplied by mere conjectTire. The base of the columns. It is thought, from the little differences between the shaft at the base and that immediately under the capital, that the base which is here exhibited did not belong to the capital shown at Fig. l,but to some of the interior columns; for the ancients always made the interior ranges of columns less in diameter than the exterior, as is to be found in the celebrated Athenian buildings, the Temple of Minerva, and the Propylea. Fig. 2. Profile of one half the fi-ont of the capital, with the measure of the volute, and proportional measures in numbers. Plate 56. FROM THE TEMPLE OF MINERVA, AT ATHENS. Fig. 1. Another example of a volute, showing the different sections and formation of the face mould ings thereof. Fig. 2. A section through A B. i'l.:i.i Fih 3. I. >' 2J I'M .C l-'liiiu llu- T.-nii.l.- ,.r MiiK r\:i ^^^ll:l^4 .11 l*|-|*' Fi^ /. JUa «. Fiyj. 4. "J ft -J 1 .,• (^s^ / I 4 "^ / ri..')4 OSL^.OllAiRl U®lf3 3® Knim iIk' Ti'iniiU' of Minci'v!i Volisis jil Vncin' V V ■< I'lMin rli.' TiMulilf >.l- H:iC'c|]ll.-< :.l ■|',-,,s. ri.jj 1' II. ^i£SC| I 'I .•.(-, '■''■"'" ll"- I'.-M1|,I MmI.TV;, I',.|,.,,S ., 1 Alli.-MS ^ti/.I. "f # GRECIAN ARCHITECTURE. 101 GRECIAN AllCHITECTURE. CORINTHIAN ORDER. On the archih-avc of the Choragic Monument at Lysicrates was the following inscription : — " Lysicrates, of Kikyna, the son of Lisithetdcs, teas citoraffiis, (or gave the chorus at his own expense.) T/ie tribe of Akamantis obtained tlte victory in the chorus of boys. T/ieon teas the performer on the flute ; Lysades, an Athenian, was the teacher of the chorus. Eeaenatus was archon." From this we conclude that on some solemn festival, which was celebrated with games and plays, Lysicrates of Kikyna, a demos or borough town of the tribe of Akamantis, exhibited at his own expense, on behalf of the tribe to which he belonged, a musical or theatrical entertainment, in which the boys of Akamantis obtained the ■(■ictory ; also, that, in commemoration of the victory, this mon- ument was erected to perpetuate the same to posterity, by the name of the archon, or magistrate, in whose time this took place. It ap- pears that the buUding was erected about three hundred and thirty years before the Christian era, in the time of Demosthenes, ApeUcs, Lysippus, and Alexander the Great. The tripod seems to have been the peculiar reward bestowed by the people of Athens on that choragus who exhibited the best musical or theatrical entertain- ment ; and we find this particular custom obtained for these tripods the name of choragic tripods. It was customary for the victor to dedicate the tripod he had won to some divinity, and to place it either on one of the temples abrcady built, or on the top of some edifice erected and consecrated by him for the purpose. Tlius they participated of the sanctity of the place, and were secured from in- jury or violence. A tripod thus dedicated was always accompanied with an inscrip- tion, so that it became a permanent, authentic, and public monu- ment of the victory and of the person who had obtained it. Stuart and Eevett deduce many circumstances to prove that it was erected for the above purpose, which appears rational and conclusive. Description of the Choragic Monument. The Choragic JMonviment of Lysicrates, which we are about to describe, is commonly called, by the mod- ern Athenians, to *ava|i tou Arnxotfl^vioj, or the Lantern of Demosthenes. This monument of antiquity, which is exquisitely \\Tonght, stands near the eastern end of the Acropo- lis, and is partly enclosed in the hospitium of the Capuchins. It is composed of three distinct parts : first, a quadrangular basement ; secondly, a circular colonnade, of which the intercolumniations were en- tirely closed ; and thirdly, a tholus, or cupola, with the ornament that is on it. There is no entrance or aper- ture in the basement, which is entirely closed on every side. The basement supports the circidar col- onnade, and was constructed in the following man- ner : SLx equal panels of white marble placed con- tiguous to each other, on a circular plan, formed a continued cylindrical wall, wlxich was divided from top to bottom into sL\ equal parts by the junction of the panels. On the whole length of each juncture was cut a semicircular gi-oove, into which a Corin- thian column was fitted with great exactness, so as eflcctually to conceal the junctures of the panels.* These columns projected somewhat more than half their diameters from the surface of the cylindrical wall, and have the Attic base. The shaft of the col- umn is fluted in a singular manner ; it contains thir- teen flutes : the lower extremities of these flutings descend below their usual limits, and are cut into the apophyges, or scape of the column, and the upper extremities terminate in the form of leaves ; the an- nular channel, immediately above them, which di- vides the shaft of the column from the capital, waa probably filled with an astragal or collarino of bronze. Under this terminated the fluting in the form of an annular tier of leaves, turning outward from the shaft of the column. This capital exhibits a specimen of the Grecian art. The annular tier of leaves springing from the neck in fonn of the palm, the acanthus forms the second tier with the flowers. Li the third tier is shown the beautiful branches and the scrolls, termi- nating under the angular extremity of the abacus, the points of which are cut short ; it in this respect, as well as in the disposition of the foliage, differs con- siderably from any other example of the Grecian Corinthian capitals. The entablature. The architrave is divided into four divisions, the band or ogee and three parallel planes or faces projecting one over the other ; the lower edges stand out one or two degrees from a per- pendicular line. The frieze of this entablature is ornamented with sculpture, representing the story of Bacchus and the Tyrrhenian pirates. The figure of Bacchus himself, the fauns and the satyrs who attended on the mani- festation of his divinity, the chastisement of the pirates, their terror and their transformation into dol- phins, are expressed in this basso riUevo with great spirit and elegance. The cornice is very plain, composed of dentils and * The two tripods are -wrought in basso rilievo on each of the panels ; they are probably of the kind described by Homer and Hesiod. 102 BASES. plain moiUduigs, in the place of the cima or cima- tium, having an upright front ; it is ornamented with scrolls and honeysuckle foliage in basso rUievo, in the Yitruvian style. This cornice is composed of several pieces of white marble, and bound together by a cupola of one entire piece. The cupola is ornamented with elegant workman- ship ; its covering imitates that of thatch or of laurel leaves ; the turret standing du-cctly over the wall re- sembles a Vitruvian scroll ; next above the lam-el leaves, the covering of the dome, spring three scrolls, at equal distances from each other, in imitation of those branches in the capital shown in this plate. The flowers that ornament the top rise from the cen- tre, and are composed of workmanship of foliage, which terminate in three divisions of scrolls, of great richness, on the top of which it is believed was sup- ported the tripod gained as the prize, from the ck- cumstancc that cavities are cut on the three principal projections in an equilateral triangle, into which the feet of the tripod were probably fixed ; and in the fourth cavity, which is in the centre, and much the largest, was erected a baluster to support the tripod. Plate 57. Fig. 1. This figure represents the elevation of the Grecian Corinthian order, from the Choragic Monu- ment of Lysicrates, proportioned to modules and minutes. Fig. 2. The inverted projection of the cornice. Fig. 3. The base is attached to the basement. Fig. 4. The capital inverted. Plate 3S. To draw the flutes of the columns of the Doric order. Divide the semi-circumference into ten equal parts ; then with one of those parts, as a radius, and the extremities of any division, as at 3 and 4, describe arcs, cutting each other in C, and through C describe a circle, or a part, and draw lines from the centre, cutting that circle, which will give the centres for de- scribing the flutes. Or thus, for deeper Flutes. Bisect any division, as 5, 6, at /; then on 5, with the distance 5 /, describe an arc / D, cutting the radius produced through 5 at D, and draw the radii through the points 5, 6, 7, 8, 9, 10, cut- ting that circle, which will give the centies of the flutes. Fig. 2. The elevation drawn from the plan. Fig. 1. To ckaw the flutes of the Ionic and Corinthian orders. Fig. 3. Divide the semi-circumference into twelve equal parts ; divide any division, as between 5 and 6, into eight equal parts ; then with a radius of three of these equal parts, on the points 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, as centres, describe the flutes, which will leave the fiUets. Fig. 4. The elevation drawn from the plan. Fig. 3. BASES. In no example of antiquity is the Doric column provided Tvith a base. Tliis circumstance, says Mr. Partington, has occasioned no small perplexity to some of those 'vrriters -n-ho seek, in every point, some analogy to the human figure. Vitruvius has indeed said that the base is a slioc, first invented to cover the nakedness of the ma- tronly prototyjie of the Ionic order. " But," says Monsieur Lc Clcrc, "I must o^^•n I cannot consider a column without a base, comparing it to a man ; but I am, at the same time, struck 'with the idea of a person ■without feet, rather than without shoes ; for ■which reason, I am inclined to believe, either that the architects liad not yet thought of employing bases to their columns, or that they omitted them in order to leave the pavement clear, the angles and projec- tions of bases being stumbling-blocks to passengers, and so much the more troublesome, as the arcliitects of those times frequently placed their columns very near each other, so that, had they been made ■with bases, the passages between them ■^•ould have been ex- tremely narrow and inconvenient." To supply this defect, as it is generally considered, most architects have employed the Allic base, which is common to all the orders except the Tuscan, though be- longing, perhaps, more peculiarly to the Ionic. We have, therefore, here given a representation of it, as furnished by Mr. Partington, from Yignola. It is seen that it consists of two tori, with a seotia and fillets between, the upper of which, iu this version, resembles an inverted ovolo. The fillet, above the upper torus, is always connected with the shaft by a curve, as is also that under the capital, for which reason they arc com- monly considered as part of the shaft. The plinth, or square mem- ber beneath, is usually understood, in Roman architecture, as an indispensable appendage to the base, though PaUadio has omitted it in his Corinthian order; but it is rarely found in the Greek speci- mens. To save tliis order, however, fiom the sad humiliation of being obliged to borrow a shoe, when required to wear one, Vignola provided it with this appendage. Ilis base consists of one largo torus, with one considerably smaller resting upon it, smmountcd by the fillet. KTnin iIk' riiiirai;!!- Momuiim-iu lU'Lysii-raU's .- -) l'l..i7 .l-ia.2. g u- ' ■- ■ \\ ^- (r- •^_) '^__ f/ r- \>' .' /•>'c?. /. i,' ji; Jt' *' *' c JWU ^ L ^ r Fia.S. c 7 i^WV I'l.-iK uVJ Fjf/4 ^'v Sj!^ttiA\r i'l .■)!! ^ 1-. ^ \.i7 5? \."J-.- ^ FT Ki ■; '1 '.■ J >6 A 1^ 21m u ? —J' < l.-v ■K •n. I-' •6- ) K. E 4lh \^ ^* 33 ) s G ENTABLATURES. 103 M. Le Clerc has, in the opinion of Mr. Partington, discovered the true reason why, at least in the latter Greek specimens, the base is omitted — namely, the very narrow intercolumniations. In the Greek order, alteration is not probable, and, perhaps, not desirable; but in the Roman, -nhero this addition has long been provided for us, and the intercolumniations adjusted accordingly, the omission would bo certainly improper. ROMAN BASES. Several designs for bases after the Roman taste are given on plate 59, which may be applied to col- umns, pilasters, and, in some instances, to rooms, chimney-pieces, &c. Plate 59. Fig. G. The Tuscan order. Fig. E and A. The Doric. Fig. B and C. The Ionic. Fig. D. The Corinthian. ENTABLATURES. The orders consist of a composition of parts. When considered in gross numbers, they consist of two parts, viz., the column and entablature. These divisions are subdivided : the column com- prises the base, capital, and their appendages, as shown in the orders. The entablature consists of the architrave, frieze, and cornice. The architrave, in all the orders, has the band. The Grecian Doric, however, does not furnish us with more than two divisions, — the band and frieze. The band, or fillet, which constitutes the upper part of the architrave, is projected under the trigljiA ; and an an- nulet is dropped from the iillet, a little on the frieze, to tlie soffit of which are attached six drops, as in the Grecian examples. In the Ionic and Corinthian orders, the Greeks have divided the frieze into three projecting parts, as sho'^^^l in the example from the Temple of Jlincrva Polias. Tlie divisions arc, 1st, lOJ ; 2d, 12 j ; 3d, 144 minutes. The Romans, in this respect, have followed the Greeks, except in the proportions of the divisions ; as seen in the Doric elevation found at Albano, near Rome; in the Diocletian Baths ; and in the example from Andrea Palladio. 2d. The frieze or entablature is ornamented, in the Doric order, with triglyphs, and sometimes with sculpture, as shown in the ex- ample from the Temple of Theseus, at Athens. Aldrich has intro- duced triglyphs into the Composite order, which I consider a com- position of the three orders. This practice, however, is seldom adopted ; although there may not be much impropriety in borrow- ing from the Doric, as well as from the two higher orders. The capital of the triglyph is from 4 to 6 minutes wide. The width of the triglyph is commonly fr-om 28 to 30 minutes, having an angle of 135 degrees from the outer comers, cutting from the face 24 minutes. The intermediate space is divided into five parts, the second and fourth being cut at right angles from the centre. The fi'icze of the two higher orders, viz., the Ionic and Corinthian, afford a variety of ornaments, of which the Romans have been very profuse ; as on the Temple of Fortuna Virilis, at Rome. See also the example from the Arch of Titus. 3d. Cornices. — This assemblage of parts affords much variety, from the plain bed mould, mutules, dentils, and modillions. The mu- tulcs are common in the Doric planceer. The dentils are common in the Ionic, and are placed between the hollow and the (juarter round, as shown in the bed mould. An example of this is found in the Temple of Fortuna Vkilis, and in the Coliseiun, at Rome. The quarter round is sometimes ornamented with the egg and dart. The Corinthian order has dentils and modillions, as shown in the example from Jupiter Stator. Tlie mouldings are often ornamented with carvings of various designs. The facia, in the Grecian Doric, projects from 27 to 30 minutes from the triglyijhs. In the Roman Doric, it sometimes projects from 34 to 37 minutes. The height of the facia varies from 7 to 11 minutes. The crown moulding is a cima recta, and, in modern times, the ovolo has been introduced in many instances, which is preferred on account of its superior strength, and the beautiful variety of light and shade which it presents to the eye. "We find some examples overcharged with mouldings, which are not only offensive to the eye, but destroy the appearance of strength and proportion. An error of this kind is found in the Diocletian Baths, in which the graceful simplicity is lost, when compared with the Grecian Temple of Theseus. In the cornice, the facia has too much projection, and is not deep enough, and would have a far better appearance were the dentils quarter round, and bead left out. They are not considered as properly belonging to the Doric order. Palladio and others (as shown in some of the Roman ex- amples given in this work) made use of a plain, simple bed mould, composed of a hollow and round, under the planceer. This is as much as belongs to the Doric. In the Ionic, the Greeks have made xise of the eclunus, dentils, an angular fillet, and a quarter round, under the planceer, as in the example from the Temple of Minerva Polias. The extraordinary projection of the dentils, rising above a plain frieze, has a beautiful effect, as well as the modillions in the Corinthian order. This mo- dilUon is frequently ornamented with foliage ; a decoration properly belonging to, and supporting, the planceer. The ornamented ovolo under the modillions, as found in the portico of the Pantheon, by its chaste appearance, occasioned by not adding a sui'plus of variety, is rendered one of the best specimens of the Romans. The example taken from the Temple of Jupiter Stator is very beautiful. The majestic proportions of the capital and entablatui'o would give it the superiority, were it not overcharged with too much finery. The addition of dentils, however, can be no objection to its pleasing effect, as, in cities, eave cornices are not often viewed to advantage at a greater distance than the angle of forty-five degrees, and within that distance the ornamented planceer shows to good advantage:. The proportions of cornices should invariably be regulated according to these distances. If at the angle of forty-five degrees, the height should be equal to its projections. If short of tliis, its projections should increase, in regular projiortion, in all its members. l"he cro«ni moulding of the cornices should be projected i^-ith soma variation, — the Grecian ovolo at forty-five degrees, — but the cima recta shoiJd not project so much, in order to open it more to the rays of light j for if the swell does not receive a strong light, it is rendered obscure at any considerable height. I have introduced in tliis place several designs for cornices, which may assist, in some measure, the fancy of those who may wish to vary from the original Greek and Roman styles and proportions. They may be executed on frontispieces, and many other places, to advantage. 104 CHIMNEY-PIECES. Plate 60. Presents five cornices, with the scale to wiiich they are drawn. The scale is supposed to be the diameter of the shaft of the column, at the bottom ; from which these designs arc figured in proportional parts. Figs. 1 and 5 arc plain plancccrs ; 3 and 4 ornamented friezes and entablatures. No. 1, plan of the plancccr of Figs. 3 and 4. Plate 61. Fig. 1. Design of a modillion cornice. No. 1, the modillion and manner of drawing it, viz. : From A radiate from 1 to 2 ; from B to 1 and 3 ; liom C to 3 and 4, which completes the lower curve. Fig. 2. A cornice without the entablature. No. 2, design of the planceer, with mutules and ornament. Fig. 3. Design of a Doric entablature. No. 3, or- namented planceer. Fig. 4. A Doric entablature and cornice. No. 4, mutules with a reset. CHIMNEY-PIECES. It is a remarkable fact that neither the Italian nor the French, nor indeed any of the continental nations, hare over excelled in com- positions of chimney-pieces. It is believed that Inigo Jones, em- inently distinguished among the arcliitects of England, ■was the first who arrived at any great degree of perfection in this important branch of architectural science. Other architects have, smco his time, wrought upon his ideas, or furaishcd good inventions of their own ; and of our many ingcnions and very able artists, -whoso prov- ince it is to execute magnificent chimney-pieces in marble, happily much in vogue, it may be said that, for taste of design and excel- lence of workmanship, they are not surpassed by those of any other nation. It was facetiously observed by Sir W'illiam Chambers, that chimney-pieces should be " so situated as to be immediately seen by those who enter, that they may not have the persons already in the room, who are generally seated about the fire, to search for." There is much good sense in this remark. As the Egyptians, the Greeks, and the Romans, to whom architecture is so much indebted in other respects, lived in warm climates, where fires in the apartments were seldom or never necessary, they have thrown but little light on this branch of archi- tecture. Amongst the antiquities of Italy, I do not recollect any remains of chimney-pieces. Palladio, indeed, mentions two — the one at Baia, and tlie other near Civita Vecchia, which stood in the mid- dle of the room, and consisted of columns support- ing architraves, whereon were placed the pyramids or funnels through which the smoke was conveyed. Scamozzi takes notice of three sorts of chimney- pieces used in Italy at his time. One of these he calls the Roman, the apcrtiure of which is surrounded only with a clumsy architrave ; another he calls Venetian, which is likewise adorned with an archi- trave, upon which arc placed a frieze and cornice, and on the sides thereof are pilasters with consoles. The third sort he calls a Padiglione. This last he particularly recommends where the walls are thin, if not being hollowed into the wall, as both the other sorts arc, but composed of a pro- jecting entablatm'c supported by consoles, termini, or caryatides, on which the pyramid is placed. This sort of chimney-piece is still very common in Italy. The Dutch are very fond of it, and it may be found in many old English country-houses. The size of the chimney-piece must depend upon the dimensions of the room wherein it is placed. Li the smallest apartments, the width of the aperture is never made less than from three feet to three feet six inches ; in rooms from twenty to twenty-four feet square, or of equal superficial dimensions, it may be four feet wide ; in those of twenty-five to thkty, from four to four and a half; and in such as exceed these dimensions, the aperture may be extended to five, or five feet sbc inches ; but should the room be extremely large, as is frequently the case with halls, galleries, and saloons, and one chimney of these last dimensions neither afford sufficient heat to warm the room, nor sufficient space round it for the com- pany, it will be much more convenient, and far hand- somer, to have two chimncy-piec"cs of a moderate size, than a single one exceedingly large, all the parts of which would appear clumsy and disproportioncd to the other decorations of the room. The chimney should always be " so situated as to be immediately seen by those who enter, that they may not have the persons already in the room, who arc generally seated about the fire, to search for." The middle of the side partition wall is the most proper place in halls and saloons, and Ihe other rooms of passage to which the principal enlranccs are commonly in the middle of the front, or of the back wall ; but in drawing-rooms, dressing-rooms, and the like, the middle of the back wall is the best situation, the chimney being then farthest removed from the doors of communication. Tlie case is the same with re- spect to galleries and libraries, whose doors of en- trance are generally cither at one or both ends. In l©i£S[H©.ja3 U^^JDJi r />,/.:'. I __ Tnrnnmnn 4 ^ ooo il:^ o o i ^) O 30 OOO OOO oco □ ^' m \>y^. -jzr L-J l_l U.-,[U^ X Em // E ??I-5J_ P H -^ .r' iv'."/. 7' /w.'J 7^ ■^ f^ O o o o o o o n 6 o o o o o o o o o 00000000030 o o o o o o & 4U^ > -^ ^^'^ idiJ .V".: FH Ji 5it=n_ji I r^ J ^1 ■\ Fi'^.4. oooo oooo oo o o c oO' C-' C) o o o OOOO oooo oo oo oooo oooo oo oo oooo oooo oo oo oo oo oooooo oooooo .vr2 .vu ©35 []©?]? y ri.i.j ^'' J 3 1^ Scalr ff/' A'a-/. (iHil hichr.i. 1 1 1 : 1 r L-^' 1 ©isslivio.-l I': n.i ^?^?;3o DOORS. 105 bed-chambers the chimney is always placed in the middle of one of the side partition walls, and in closets, or other very small places. It is, to save room, sometimes placed in one corner. Whenever two chimney? are introduced in tlie same room, they must be regularly placed, either directly facing each other, if in different walls, or at equal distances from the centre of the wall in which they are both placed. The Italians frequently put their chimneys in the front walls between the win- dows, for the benefit of looking out while sitting by the fire. The proportion of the apertures of chimney-pieces of a moderate size is generally near a square ; in small ones, a trifle higher ; and in larger ones, some- what lower. Chimney-pieces are made either of stone or marble, or of a mixture of these with wood, scagUola, or molu, or some other unfragile substances. Those of marble are most costly, but they are also most elegant, and the only ones used in high-finished apartments, where they are seen either of white or variegated marbles, sometimes iidaid and decorated with the materials just mentioned. All their orna- ments, figures, or profiles are to be made of the pure white sort ; but their friezes, tablets, panels, shafts of columns, and other plain parts, may be of party- colored marbles, such as the yellow of Sienna, the brocatello of Spain, the jaspers of Sicily, and many other modern as well as antique marbles firequently to be had in this country. Festoons of flowers, trophies, and foliages, frets, and other such decora- tions cut in white statuary marble, and fixed on grounds of these, have a very good effect. But there should never be above two, or at the utmost three, different sorts of colors in the same chimney-piece, all brilliant and harmonizing with each other. In the inferior class of houses, and in upper chambers, wood is generally used in the construction of chim- ney-pieces, painted and varnished so as to resemble marble. The use of wooden chimney-pieces, when judiciously applied, materially lessens the expense, and answers every purpose of utility or ornament. In many places, the wildest notions have been in- dulged in the designs of this part of architecture. Sometimes we see a chimney-piece, the shelf of which is supported on a numerous variety of mouldings, piled one above the other until they project nearly as much as the shelf itself; this, I contend, is useless and out of , good taste, for they cannot be seen to any advantage, 14 as in ordinary eases they fall below the eye, except when seated, and then they are so nearly on a level with it that they cannot be seen to any advantage. If, therefore, one half of the expense of mouldings should be laid out in the frieze and pilasters, or col- umns, they would have a much better appearance, and display a more refined taste. Plate 62. On tills plate will be found two designs for com- mon chimney-pieces, drawn to a scale of feet and inches. Plate 63. On this plate will be found two designs for chim- ney-pieces, as executed by Isaiah Rogers, Esq., in the Tremont House, Boston, Massachusetts, drawn firom the same scale as plate 62. DOORS. In our northern climate, the fewer doors a room has the more it ■will be comfortably habitable ; for as vre have much more cold than hot weather, it is yery necessary to make the rooms as close as pos- sible, otherwise they will not be fit to live in the greater part of the year. Wherefore it will be advisable never to make either more windows or doors than are absolutely necessary. In this country, the real and feigned doors of a room, with their ornaments, fre- quently cover so great a part of the walls that there is no place left for either pictures or furniture. Doors of entrance to private houses should not be less than three feet wide, nor more than six feet ; but to churches, theatres, and other public structures, where there is a constant ingress and egress of peo- ple, and firequently great crowds, the apertures must be larger, and their width cannot be less than six feet, nor should it exceed ten or twelve. Li settling the dimensions of the apertures of doors, regard must be had to the architecture with which the door is surrounded. K it be placed in the inter- columniation of an order, the height of the aperture should never exceed three quarters of the space be- tween the pavement and the architrave of the order, otherwise there cannot be room for the ornaments of the door. Nor should it ever be much less than two thirds of that space, for then there will be room suf- ficient to introduce both an entablature and a pedi- ment without crowding; whereas, if it be less, it will appear trifling, and the intercolumniation will not be sufficiently filled. The apertures of doors placed in arches are regulated by the imposts, the top of the 106 DOORS. cornice being generally made level with the top of the impost. And when doors are placed in the same line with windows, the top of the aperture should level with the tops of the apertures of the windows ; or if that be not practicable without making the door much larger than is necessary, the aperture may be lower than those of the windows, and the tops of all the cornices made on the same level. With regard to the situation of the principal en- trance, Palladio observes, that it should be so placed as to admit of an easy communication with every part of the buUding. Scamozzi compares it to the mouth of an animal; and as nature, says he, has placed the one in the middle of the face, so the archi- tect ought to place the other in the middle of the front of the edifice, that being the most noble situa- tion, the most majestic and convenient. In several of the palaces at Rome, as those of the Pamfili in the Corso, and of the Bracciano, at Santi Apostoli, there are two principal entrances in the same aspect ; but this is, in general, to be avoided, as it leaves strangers in doubt where to seek for the state apart- ments, which should always be contiguous to the principal entrance. In interior dispositions, the doors of communication must be situated, as much as pos- sible, in a line ; the advantages of which are, that it contributes towards the regularity of the decoration, and facilitates and shortens the passage through the apartments in summer ; or on public occasions, when the doors are set open, it produces a free circulation of air, and likewise gives a much more splendid appear- ance to the apartments, by exposing to view at once the whole series of rooms, which is more particularly striking when the apartments are illuminated, as on occasions of balls, routs, or other rejoicings. There should, if possible, be a window at each end of the building, directly facing the line of the doors of com- munication, so that the view may be more extensive, and take in at once not only all the rooms, but like- wise parts of the gardens, or other prospects sur- rounding the building ; and whenever this is not practicable, it will do well to place mirrors at each end of the apartment, or to counterfeit doors, and fill them with large plates of glass, or with sashes and squares of looking-glass, as is the custom in France, which by reflection mu'tiply the rooms, the doors, and other objects, making an apartment, though lim- ited or small, appear very considerable. The door of entrance from halls, vestibules, or ante- chambers, either to the principal apartment or to any even of the inferior ones, should be in the middle of the room, if possible, and facing a window ; those that lead to galleries, or any other long rooms, should be in the middle of one of the ends ; and in general, all entrances should be so contrived as to offer to view, at the first glance, the most magnificent and extensive prospect of the place they open into. The doors of communication from one room to another of the same apartment must be at least two feet dis- tant from the front walls, that the tables placed against the piers, between the windows, or other pieces of furniture put there, may not stand in the way of those who pass. In bed-rooms, care must be taken to make no doors on the sides of the bed, unless it be to communicate with a water closet, wardrobe, bath, or other eonveniency of that kind, as well on account of t"he draught of air as of the noise commu- nicated through them, or attending their opening and shutting; both of which are always troublesome, and on some occasions dangerous. Neither ought doors to be placed near chimneys, for the same reasons, and as the opening of them would disturb those who sit by the fire. In composing doors, regard must be had, both in their size and enrichments, to the place they lead to. Those that give entrance to churches, theatres, state apartments, or other places of consequence must be large and profusely enriched ; but such as open to humbler habitations may be small and sparingly decorated, unless the nature of the building should require otherwise. Where several doors are in the same aspect, as on the inside of a hall, saloon, or gal- lery, they should be all of the same size and figure, unless there be many, in which case the principal ones, provided they stand in the middle of a side, or in the middle of the ends of the room, may be larger, of a different form, and more abundantly adorned than the rest. But, whenever more than two sorts are introduced in one room, it always tends to con- fuse the spectator. The commonest sort of doors are made of pine, painted in various manners, and the better kind of them are of mahogany, or oak, or different sorts of rare wood, inlaid. With regard to their construction, strength, beauty, and straightness are to be consid- ered ; all which purposes are answered by composing them of several panels. The number of these must depend on the size of the door, which should like- TOrf.9!l(SD\39 DFOIS rp)®®!^©. I'l.ei' Tg^;^^^^=^"^-^ .-::^ , X , , ,CJ l| // V, n 'n ii 1 aijcei^js /©If! ©aru'-SQitDE ®®vfi)ias. Pl.Oo /'/r/. / Fi//. 2. D li ^' y ^1 ! t fu-ng 1 p ! 1 1 u ll 'i 'i r 1 1 CiULlid ._.J 1 Fiyj. 3. D^ ^ /»/. ^. n z?^.^ 'i" I c^ 'k s- 1 * p ■^ IFia®lR!l''/ ®®t05S, I'l.tiii Fif,. t. WINDOWS. 107 wise regtilate the thickness both of the panels and the framing. If the doors be adorned with orna- ments of sculpture, as is sometimes usual in very rich buildings, they must either be sunk in, or kept very flat upon, the sm-face, both for tlic sake of lightness, and to prevent their being broken. The panels may be either raised or flat, and surrounded with one or two little plain or enriched mouldings, contained in the thickness of the framing, not projecting beyond it, as is sometimes seen in old buildings. Doors that exceed three feet and a half in breadth are generally composed of two flaps, by which means each part is lighter ; when open, does not project so far into the room ; and when required, may be made to fold entirely into the thickness of the wall. It is to be observed, that all doors should open inwards ; otherwise, in opening a door to give a person en- trance, it must open in his face, and may chance to knock him down. For a variety of doors, in the modern taste, see plates 64, 65, 66. Plate 64. On plate 64 will be found sLs designs for inside doors, with the finish. The proportions of each part are figured, and across each will be seen a sectional plan, showing panels, &c., either raised or sunken, as the case may be. A is an elevation of a circular head door, and is designed for an outside door. The architraves of each at 1, 2, and 3, are those on plate 30. — Editors. Plate 65. Figs. 1 and 2. Designs for outside doors. Figs. 3 and 4. Horizontal section of the same, with a projection of the threshold, steps, and pilasters. Fig. 5. Section of the style, panel, and moulding. Fig. 6. Section of the pilaster and plinth. Plate 66. Fig. 1. Front door finished in the Ionic style, the pillars supporting the cap in the wall. Fig. 2. The recess and side view of the column. Fig. 3. The recess of the door from the column and step on which the pillars stand. Fig. 4. The ceiling of the recess and inverted cap- itals of the column. Fig. 5. Style, panel, and moulding of the door. Good taste has taught us to avoid the multiplica- tion of small members on inside finishing, and to adopt in their place plane surfaces, or appropriate mouldings of a proper size with their necessary ar- rangements, as it is much easier executing a proper finish of painting : the necessary application of a pumice stone or sand paper, to produce a smooth surface, is rendered impracticable, by numerous close quirks, without injuring the paint on the otJHT parts. On a plane surface, the work is much easier cleansed ; and by this style of finish, which rejects every thing that is mean and trifling, that manly character is given to the work which the refined taste of ancient and modern architects have so much admired. The Proportions of the Architraves and Pilasters for inside Finish. The architraves for windows and doors in any one apartment should be nearly of the same width, where a uniformity of appearance requires it. Add together the width of the door and of the window and the splay ; find the mean width ; then divide it by 7, which gives the width of the architrave ; but where fancy pilasters are required, divide by 6, which gives one sixth of the width of the opening for the width of the pilasters. The designs in plate 30 give the full size that those in general use are executed. CONSTRUCTION OF WINDOWS. There has been in this branch of architecture, as well as all oth- ers, a variety of changes and modifications to suit the taste and fashion of the times. In civilized countries, convenience and beauty are consulted ; whereas, in barbarous countries, strength and safety are their most necessary requisites. In this enlightened and happy country, every man of taste adorns his habitation with such as he may deem to be most convenient, economical, and ornamental. The enriching of windows with ornaments is of ancient date, and has been handed down to us in common with most of the grand princi- ples of the arts and sciences. The proportions of the apertures of windows de- pend upon their situation ; their width in all the stories must be the same, but the different heights of the apartments make it necessary to vary the heights of the windows likewise. In the principal floor it may be from two and one eighth of the width to two and one third, according as the rooms have more or less elevation ; but in the ground floor, where the apartments are usually somewhat lower, the aper- 108 WINDOWS. tures of the windows should seldom exceed a double square ; and when they are in a rustic basement, they are frequently made much lower. The windows of the second floor may be, in height, from one and a half of their width to one and four fifths ; and those of attics or mezzanines, either a perfect square or somewhat lower. The character of the order in which the windows are employed, and that of the profiles with which they are enriched, must likewise, in some measure, be consulted, and the apertures be made more or less elevated, as the order of the whole decoration, or of the window itself, is more or less delicate. The windows of the principal floor are generally most enriched. The simplest method of adorning them is with an architrave surrounding the aperture, covered with a frieze, and cornice suited thereto ; but when the aperture is remarkably high with respect to its width, it becomes necessary to spread the orna- ments on the sides thereof, by flanking the architrave with columns, pUasters, or consoles, in order to give the whole composition an agreeable proportion. The windows of the ground floor are sometimes left entirely plain, without any ornaments whatever ; at other times, they are surrounded with an archi- trave, or with rustics, or have a regular architrave crowned with its frieze and cornice. Those of the second floor have generally an architrave carried entirely round the aperture; and the same is the method of adorning attic or mezzanine windows. But these two last have seldom or ever either frieze or cornice ; whereas, the second floor windows, when- ever their aperture approaches a double square, are often adorned with both. The sills of the windows on the same floor should be on the same level, and raised above the floor from two feet nine inches to three feet at the very most. When the walls are thick, they should be reduced under the aperture of the windows, for the conven- iency of looking out, and seats may be contrived to fit these recesses, as is the custom in many modern houses. In France, and now too often here, the win- dows are carried quite down to the floor, which, when the building is surrounded with gardens or other beau- tiful prospects, renders the apartments exceedingly pleasant in summer, but then they become exceed- ingly cold in winter ; and the iron work, which in France, and latterly very nmch here, is placed on the outside by way of fence against accidents, ought never to take place where regular architecture is intended ; for all the gilding and flourishing in the world can never make it tolerably accordant with the rest of the composition. In regular built houses, the sills of the windows on the ground floor should be raised six feet above the pavement on the outside of the building, to hin- der passengers from looking into the apartments ; but when this cannot be done without raising the floor itself more than may be necessary, the lower parts of the windows may be furnished with blinds. The tops of the apertures of windows should never, within the apartments, be carried up close to the cor- nice of the room. A sufficient space ought always to be left for an architrave, or at least two or three inches between the architrave and cornice — a space usually occupied by the cvirtain lath. The interval between the apertures of windows depends, in a great measure, on their enrichments. The width of the aperture is the smallest distance that can be between them, and twice that width should, in dwelling-houses, be the largest ; otherwise, the rooms will not be sufficiently lighted, and the building will have rather the appearance of a prison than of a structure calculated for the conveniences and enjoyments of life. The purpose for which the building is intended should regulate the quantity of light to be introduced ; and, therefore, in dwelling- houses, and all places where comfort and pleasure arc the main purposes, there cannot be too much. But in sacred structures, which should affect the mind with. awe and with reverence, or in other great works where grandeur of style is aimed at, it should be cautiously and rather sparingly distributed. The windows nearest to the outward angles must be at least the width of their aperture distant from the angle, and a larger space will be still more seemly, and render the building more solid. In all the stories of the same aspect, the windows must be placed exactly one above the other, and those to the left symmetrize with those to the right, in size, situation, number, and figure. The reasons for all these things are obvious enough, and, therefore, it is needless to mention them. The licentious practice of intermitting the architrave and frieze of an order in the intervals between the col- umns or pilasters, to make room for windows and their enrichments, which are carried close up to the cornice, can on no account whatever be suffered in WINDOWS. 109 regular architecture, it being in the highest degree absurd to carry the windows above the ceiling, and great want of judgment in an architect to intermix and crowd together such a number of rich complicat- ed parts as are those of the entablature of the order and the entablatures of the windows. Besides, the whole beauty of the order, when so mutilated, is destroyed, its proportions and figure being entirely changed. An interruption of the whole entablature to make room for a window, and converting it into an impost to the architrave, is a license equally un- pardonable. The common sort of builders in this country are extremely fond of variety in the ornaments of win- dows, and, indeed, in every other part of a building, imagining, probably, that it betrays a barrenness of invention to repeat the same object frequently. I have seen a house with only eleven windows in the whole front, and yet there were seven different sorts. At another place, the case is the same, there being seven or eight sorts of windows in the same aspect ; and the like is to be met with in many other build- ings, both in town and in the country. These in- ventive gentlemen would do well to give their atten- tion to some professors of the mechanic arts, who, though exercising their talents on meaner objects, are nevertheless worthy of their imitation. No taUor thinks of employing seven or eight kinds of buttons on the same coat ; a cutler will not make ten dif- ferent sorts of knives for the same set; and if a cabinet maker be trusted to furnish a room, he sel- dom introduces more than one or two sorts of chairs : their practice is founded on experience ; the general approbation of mankind is the standard they go by. We do not discover, either in the works of an- tiquity or those of the great modern architects, any traces of this childish hankering after variety. The same object is frequently by them repeated a hun- dred times over ; and this is one of the causes of that amazing grandeur, that noble simplicity, so much to be admired in their productions. This sameness must, however, have its limits ; for, when carried too far, the imagination of the beholder stagnates for want of occupation. In the most ad- mired marks of architecture, we find the same objects generally continued throughout the same level : thus one order and one sort of windows or niches gener- ally reign throughout the story ; but in other stories. where the eye and the imagination necessarily as- sume a fresh course, the decoration is altered. Sometimes, however, it may be necessary to in- crease the size, and vary the figures, of the windows, either in the centre break or in some other prominent part of a front, in order to light a saloon, a gallery, or a hall higher than the rest of the room. But then it will always be advisable to repeat the same form if simple, as an arch, three, five, or more times, accord- ing to the extent of the plan, so that the mind may be in some degree satiated before it is conducted to a new object. Venetian windows and Venetian doors, too, are on some occasions necessary, particularly in small buildings, to light a hall, a vestibule, or such other rooms as cannot admit of two windows, and yet would not be sufficiently lighted with one. But where they can be avoided, it is best ; for the col- umns which separate the large interval from those on the sides form such slender partitions, that, at a distance, they are scarcely perceived, and the whole looks like a large, irregular breach made in the wall ; and, however advisable it may be to repeat the same form as has above been mentioned, the repeti- tion of these Venetian windows should always be avoided. The sashes of windows are generally made of pine, cherry, or mahogany, and sometimes of iron, copper, or other metals. Our artificers excel in these works ; they make them very neatly, and though in appear- ance slight, very strong. The lights of glass are proportioned to the size of the windows, there being commonly three in width and four in height, what- ever be the dimensions of the window ; each sash is composed of two equal parts, placed one above the other, and either the lowermost, or both of them, being hung on pulleys and counterpoised with weights, and moved up and down with great ease, the weights being concealed. The shutters are always within the apartments wherever beauty is aimed at, those on the outside destroying the appearance of the front. They are divided into several vertical slips, folding behind each other, for the conveniency of ranging or boxing them, when open, in the thickness of the wall. Each slip or fold is framed and composed of several pan- els, either raised or flat, surrounded with small mouldings contained in the thickness of the fram- ing, which, when the profiles in the room are en 110 WINDOWS. riched, should likewise be so, at least on the fold that faces the aperture, when the shutters are turned back ; the front of which must stand flush with the inner edge of the architrave surrounding the window, all the other folds being ranged behind it. I have given, in plate 67, the mode of finishing window frames, sashes, and shutters. Plate 67. Fig-. 1 shows the disposition of the members of a windoio frame and shutters. No. 1. The outside moulding against the wall. No. 2. The outside casing. No. 3. The pulley style. No. 4. The inside casing. No. 5. The back casing. No. 6. The parting slip. •,, . No. 7. The parting bead. No. 8, 8. The weights. No. 9. The recess of the wall. No. 10, 10, 10, 10. The styles of the shutters. No. 11, 11. The panels of the shutters. No. 12. The back furring for the splay of the window. No. 13. The ground. No. 14. Section of the pilaster. No. 15. The back Uning. No. 16. The thickness of the plastering. Fig-. 2 shows the disposition of shutters folding- back on a right line toith the plastering. No. 1. The inside casing. No. 2. Hinge casing. No. 3, 3, 3, 3. Styles of the shutters. No. 4, 4. Panels. No. 5. Back casing. No. 6. Box casing. , 4 No. 7. Plastering. No. 8. Band moulding. Fig. 3. Section of part of a shutter. No. 1. The style. No. 2. Panel. No. 3. Moulding. Fig. 4. Moulding, different from Fig. 3. Fig. 5. Section through the frame and sash, and shows the manner of selling the sash into the frame. No. 1. The manner of joining the soffit to the frame. No. 2. Cap of the frame-. No. 3, 3. Casings of the frame. No. 4. Top rail of the sash. No. 5. Munten of the sash. No. 6, 6. Meeting rails. No. 7. Munten. No. 8. Bottom rail. No. 9. Window sill. No. 10. Stop bead. No. 11. Back. No. 12. Back bead. No. 13. Outside moulding. Figs. 6 and 7. Sections of sash muntens. Plate 68. On plate 68 will be found a plan, elevation, and section of a French window, with the scale by which it was drawn. No. 1 shows the elevation ; No. 2, the plan ; No. 3, a section ; No. 4, a section of a part of the sUl and the sash ; A is a small fillet to prevent the water being driven beneath the sash ; and B is a channel to receive the water that may run down on the outside behind the fillet ; the dotted line C is another channel at right angles with B, to take the water to the outside. B shows the manner of constructing the meeting styles. The finish for the window may be either of the architraves shown on plate 30 ; and the manner of constructmg the shutters is shown on plate 67. Plate 69. Plate 69 is a design for an oriel window. Figure 1 shows the front elevation ; figure 2, the side elevation ; figure 3, the plan ; and figure 4, the detail of the base. The scale is placed with the plan, by which the sev- eral parts may be ascertained. Plate 70. Plate 70 * is a part of the details of plate 69. Figs. 1 and 2 are the trusses at D and A, and B is a de- lineation of the leaf at C. Fig. 3 is a truss or console. * This plate, with plate 69, was dcslgued and drawn by Mr. Shaw, and we have inserted it as being the modern production of one who has the honor of being among the earliest of the American architect- ural ■writers. Mr. Shaw's first edition of Civil Architecture was pubUshed more than twenty-five years ago ; and since then he has contributed, in no small degree, to the advancement of his much- beloved science, both practically and theoretically. He is now in the 65th year of his age ; but, notwithstanding his advancement in years, his desire is as strong as ever for the application of the correct principles of architecture in buildings of every kind. — Editors. ''//. / nA\7 J Iw. -S. C.J o I n m rjt\ Ft.,1 .3 iyr.4. A_l o'rasKKSiK] mawm®w. I'M. Slvlc nl li ®'i\air'.iL wapn®®^. n.i.!i ' 'ij jiuymjjyinmiiOiLLJUUULiuuuuuuuuuuuujuuuuu'jjgm rif/.i A, !L,^^5te ')} \^--- ^ w. ! I i'.lrv.ili.Mi ,.!■ Oi-iil Wi UUUUULIJUULIUUJU, ' , ] 1 j 1 ! i I 1 , 1 ', ' T ■ «■„.? ^))U: 1 Uns.-.Jliill .liz. . "J-iacygSi? AR!!© 'C-'PR-i??©!}.?,. I'l.7' J %h ^\^ ri.i. ELEMENTS OF FOLIAGE. Ill FOLIAGE. Both the elements and composition of foliage arc here consid- ered, and illustrated by plates. The examples are taken from the remains of the most esteemed buildings of Grecian and Roman an- tiquity. The learner is recommended to go through all the variety of ornaments exhibited in this department, by which means he will be enabled to apply himself to any other species, however different. DEFINITIONS. 1. An artificial arrangement or disposition of leaves is caMed foliage. 2. The subdivisions of single leaves are called raffles. The leaves which are chiefly used in architec- ture are the acanthus, olive, parsley, laurel, and lotus. 3. All artificial arrangement of leaves, branches, fruit, flowers, drapery, &c., either singly or combined in any manner with each other, are called ornaments in architecture. 4. A string, consisting of flowers, imit, leaves, and branches, either singly or intermixed with each other, and supported at the tsvo extremes, the middle part forming itself into a curve by its gravity, is called a festoon. 5. A curve line, which is continually changing its position in conb-ary directions on the same side of it, — that is, first concave and then convex, concave again and then convex again, and so on alternately, in this manner, to any number of curves of contrary flex- ure, — is called a serpentine line. 6. If fi-om a stalk, in the form of a serpentine line, a number of branches issue out, twisting themselves in the form of spiral lines, on each side of the ser- pentine, in all the concave parts on the alternate sides of it, and if these spirals and the stalk be deco- rated with foUage, — a composition so formed is called tvindiriff foliage. TO DRAW ORNAMENTS, PROBLEM. The learner should, in the first place, draw a great variety of curve and spiral lines of different descrip- tions, and compare these figures with each other, by which means he will be able at sight to distinguish each particular species of curve from another ; then he ought to endeavor to imitate, with precision, the same things by hand in every variety of position which he can suggest to himself, and hence he will acquire a freedom of hand in every direction. When he proceeds to copying leaves, a general outline ought to be drawn, circumscribing the whole leaf; he should then form outlines of aU the raffles, and round every compartment, circumscribing all the different sets of points or raffles, and afterwards proceed to draw the raffles themselves. The learner having after sufficient practice in copy- ing acquired a freedom of hand, he is advised to draw from nature a variety of such things as will be most suitable for the purposes to which they are to be applied. By so doing, the parts of his composi- tions will always appear rich and natural, and hence he will obtain a greater facility of invention. Hav- ing had sufficient practice in drawing from nature, he may then apply himself to the designing of orna- ments ; for which purpose he wiU find the first part of the problem, viz., that of drawing curve and spiral lines by hand, to be of the utmost utility in forming the general outline of his design ; and for finishing the smaller parts, such as raffles, flowers, fruit, &c., he must apply the knowledge he has acquired in drawing from nature, which will complete his composition. LEAVES. Of the acanthus, bear's breech, or brank ursine, there are several species. 1. The moUis, or common bear's breech, a native of Italy. 2. The spinosus, or prickly bear's breech, the leaves of which are deeply jagged in very regular order, and each segment is terminated with a sharp spine, as is also the complement of the flower, which render it troublesome to handle them. 112 ELEMENTS OF FOLIAGE. 3. The ilictfolious, or shrubby bear's breech, grows in both the Indies. It is an evergreen shrub, which rises about four feet high, and is divided into many branches, garnished with leaves like those of the com- mon holly, and armed with spines in the same man- ner ; the flowers are white, and shaped like those of the common acanthus, but smaller. 4. The nigra, or Portugal bear's breech, with smooth sinuated leaves, of a livid green color. 5. The middle bear's breech, with entire leaves, having spines on their borders. EXAMPLE. Plate 71 Shows the method of beginning to draw leaves, as given in the general problem 1. Suppose it were required to draw or copy plate 72, either of the same size, or in any other ratio to it. First inspect plate 72, and draw with a pencil a faint curve line, circumscribing the contour or general out- line of Fig. 1 ; then describe curve lines similar to it, as at Fig. 1, plate 71 ; then draw lines faintly with a pencil, circumscribing the compartments or divis- ions of Fig. 1, plate 72 ; then draw lines in a similar manner, as at Fig. 1, plate 71, observing that all the parts are similar to Fig. 1, plate 72 ; next draw the raffles and veins in the compartments of Fig. 1, plate 71 ; and, lastly, with a pen draw in ink all the parts of the leaf represented by Fig. 1, plate 72; then rub your drawing clean ; the pencil lines wiU be rubbed out, and the ink lines will be left, and will represent a figure similar to Fig. 1, plate 72. This explanation will be sufficient for aU the fol- lowing examples, however dissimilar they may be. In the following descriptions, it wUl be only neces- sary to mention the names of the buildings from which the examples were taken. Fig.l No. 1. Fig. 2 Athens, tlienes. No. 2. Fig. 1. No. 1. Plate 72. is taken from the Arch of Adrian, at Athens. The profile of Fig. 1. . From the Monument of Lysicrates at commonly called the Lantern of Demos- Profile of ditto. Plate 73. From the Temple of Pola, in Istria. Profile of ditto. Fig. 2. From the Arch of Adrian, at Athens. No. 2. A profile of ditto. Fig. 3. Elevation of a leaf taken from the capi- tals of the columns on the Baths of the Diocletian, at Rome. No. 3. Profile of ditto. KOSES IN THE CAPITALS OF COLUMNS. Plate 74. Fig. 1. Elevation of the rose in the abacus in the Temple of Vesta, at Tivoli. Fig. 2. The elevation of a rose taken firom the Temple of Jupiter the Thunderer, at Rome. Fig. 3. Elevation of a rose from the abacus of the capitals of the Temple of Vesta, at Rome. Fig. 4. Elevation of a rose in the abacus of the capitals of the pilasters of the frontispiece of Nero, at Rome. Plate 75. Fig. 1. Elevation of a rose in the abacus of the capitals of the Arch of Titus, at Rome. Fig. A. Elevation of a rose in the abacus of the capitals of the Pantheon, at Rome. Figs. 2 and 3 are designs for the ornaments of mo- dillions in cornices or corner pieces for pilasters. Plate 76. Fig. 1, the outline ; and Fig. 2, the shadowed leaf taken from a frontispiece. Plate 77. Fig. 1. From the portico of the Temple of Anto- ninus and Faustina, at Rome. Figs. 2, 3, and 4. For corners and centres of panels. ORNAMENTS FOR MOULDINGS. Plate 7§. No. 1. A general outline of Example 1. No. 2. The outline of Example 2, from the cima- tium of the Temple of Minerva Polias, at Priene. Example 3. From the cima recta in the cornice of the Temple of Bacchus, at Teos. iitSOE^I?? eif [F®[U1A©1 . A':/. Fiff.l. J7V> ./ Fiff2. ■^izw. l'l.72 /•'/,/. J. a:-/ /■'l: .vri'. ^IW% 1^" 'Mme^ (©[?• i^oiLUtt©^. I'l.-. Fic/. I :x'?2. Fu,. 3. I'l.71 .1" I /■y.f ; A".' '1. N^':3. \rrn7V >-7 E(U€MS!iW© ®[? [F®[LQA®i; . I'l.; a: I. //./. ■!. J?':'. ^^r^ A ^^^ n) n.7(i iiLiiiiassa'ir© ®i? iFOiLOtfiois , l'l,77 I't'/ /. 'iixh^^^M mi ^44 /■•„, /■}„ -■',. n 7is SvD5fli;xc)so'uij@tt m iF®[LaAisis: . E x/ .y. /•»/ //. /■'ill -? /■■/'. I-''.'/:')- > /•;;/,. I'l II.' 33~ n T II H LI I'M a I I I I w . X"^ LI II i i: II II — TT- II II II II II I L -r \ \ - 1 1 /' / 'v_ ' a i f ': . ', , 1 ' ~n 1 \ /''/r/ / // 1 /> — 1 '< ~fr , — - . — r /■ !^ ._ /, 1 r/ ^ ! j ' 1 — 1 — 1 ^- 3^. 3. . .,:'■■ ,. ' ■■ ■■■■■,■•-. './..;,. ' 'i >f:yi- '"Pf;::y-f m;^;:■^y";;;i. -J / 1 i i s / _ , i 1 It 1 ^ 1 J> i 1 J / 1 1 i ! j - ^ -—\ 1 — 1 1 t i i i '7 \ 1 1 1 / ..„l I ) 1 1 i 1 • i i 1 i 1 1 1 1 fT I'l II. 1 F>^.Z. Fi^. 3. CARPENTRY. 117 To lighten the Girders. Having grooved the sides of the flitches for the trussing pieces, so as only to be close at the ends, about an inch and a half deep on each side, and having greased the head of the lung bolt, and put the whole slackly together sideways by the screws, proceed then to turn the nut of the Idng bolt, and let another person strike the head with a mallet ; the stroke will make the king bolt start every time it is hit, and give fresh ease for the turning of the nut. By this means, the girder may be cambered or crowned at pleasure : the deflection from the straight line is generally one inch in twenty feet. Fig. 7 shows the manner of joining the beam to the wall plate. Fig. 8. The manner of keying the tenon through the girder. Fig. 9. Profile of the tusk tenon. PLANS OF FLOORS. Plate 83. Fig. 1. Plan of the floor, suitable for buildings of any magnitude. a a a a a, girders resting upon the walls, b b b bi binding joists, c c c, trimmers, d d d d d, bridging joists. Fig. 2. Section of the floor. Fig. 3 shows the method of framing floors with plank or deep joists. a, the girder resting upon the walls, and should be 10 by 12 inches, b b b b, trimmer joist, 4 by 12 inches, e e e, joist, d d d d, wall girders, 6 by 12 inches, c c c, bridging joist, 2 by 12 inches. This floor is adapted to rooms 16 or 18 feet square, and the size of the joist should be 12 inches by 2^ or 3 inches. . DESIGNS FOR ROOFS. A roof, in architecture, is a cover of a building for protecting its inhabitants from disagreeable changes of weather, and from the depredations of evil-dis- posed persons ; but a roof in carpentry is the timber framing made to support the actual covering of boards, shingles, slate, lead, &c. As the roof may be made one of the principal ties of a building, it should not be made too heavy to burden the walls, nor too light to be incapable of keeping them to- gether. The principal timbers of a roof arc the wall plates, tie beams, principal rafters, common rafters, pole plates, purlines, king posts, queen posts, struts, strain- ing beams, strong sUls, &c. Hence, since the pres- sure of the roof is wholly discharged upon the wall plates, these should be made of sufficient thickness and breadth to distribute the weight of the roof to the best advantage. Plate 83. Fig. 1, a a a a, wall plate ; b b, jack beams; c c c c, tie beams ; d d, ridge line and jack beam ; e e e e, dragon piece ; ////, angle tie ; g- g- g, hip rafters ; h h, jack rafters ; i i, principal rafters ; j, king post ; k k, strut braces. To find the length and backing of hip rafters. Draw 7, 4, 8, the base lines ; then draw 4, 5, at right angles with 8, 4, which will give the perpen- dicular height of the backing of the hip rafter. From 9, extend one foot of the dividers to 10 ; de- scribe the arc, cutting the base line at 2 ; then the lines from 2 to 1 and from 2 to 3 give the angle required for the backing, c, a section of the hip rafter. To find the angle and intermediate ribs of octagon roofs. Fig. 2 is the plan of an octagon dome, a b being the base line of the given rib. No. 2 shows the curve of the dome, in this case half of a circle drawn from the centre a. Draw a 1, cutting the circle at 1 and at right angles with d b, and produce it to a ; divide b 1 into seven or more equal parts. Make a b No. 3 parallel and equal to a b No. 1, b e equal to 6 c No. 1, and draw e a. Then draw ordi- nates from a b No. 2 to a e No. 3, parallel to a 1, cutting the circle in No. 2 at 2, 3, 4, 5, 6, 7, and a e No. 3 at 2, 3, 4, 5, 6, 7. Draw a 1 at right angles with a e, also 2 2, 3 3, 4 4, 5 5, 6 6, and 7 7, parallel to a 1, and equal to 7 7, 6 6, 5 5, 4 4, 3 3, 2 2, and a 1 in No. 2, and then trace the curve c 7 6 5 4 3 2 and 1, which will, when placed in its right position, correspond with the given circle. 118 CARPENTRY. To find the form of a board to bend upright to the crown. Fig. 2. Produce the line a fto e No. 1. Take the divisions 2 3 4 5 6 7 on the curve line b 1 No. 2, and lay them from / in F along the line 1111, &c., to e; then the line/e No. 1 will be equal to the curve line i 1 No. 2. Transfer the ordinates 2 3 4 5 6 7 in the angle a b e No. 3, and lay them from / in F No. 1 along the Ime 1111, &c., at right angles with the line/e, and set them off on each side to 1 7, 1 7, 1 6, 1 6, 1 5, 1 5, 1 4, 1 4, 1 3, 1 3, and 1 2, 1 2. Those, when traced, will give the form of the board F. Fig. 3. An octagon roof of a different curvature from that represented in Fig. 2, but is formed on the same principles. Plates 84, 85. On plate Nos. 84 and 85 we have given designs for framing large roofs without wooden king or queen posts, substituting iron rods in their stead. To whom we are indebted for this method of framing we have not been able to learn with any degree of certainty. It may, however, be considered of quite modern invention ; for, as the result of a careful in- vestigation, we have found no example of longer standing than thirty years, and have not found the idea in any published work, with the exception of some of the recent writings of the late Asher Ben- jamin, Esq. This method was vised by him as early as the year 1828, and after that time it was intro- duced into nearly all the large roofs he constructed ; and although he may not have been the first who has used it, yet, as far as we can learn, he has done as much as any other person to introduce it into general use. It was published by him in his Build- er's Guide, in 1839, and the principle involved has received the approbation of nearly all the principal architects of Boston. Mr. Charles G. Hall, archi- tect of this city, adopted it some eighteen years since, and used it in some of the largest buildings in this vicinity. The roof over the large hall of the Fitchburg depot, in this city, is a fine example of this method of framing, and has fully dcmonstr,ated its utility. The floor of this hall is 166 feet long, and 76 feet wide, and is entirely supported by the roof. On the occasion of one of Jenny Lind's con- certs which was held there, it was filled, together with the large passage, to its utmost capacity, which, according to the experiments of Tredgegold, Rennie, etc., was no less than the enormous weight of 1,873,960 pounds, or nearly 937 tons ; and, so far as can be ascertained, this roof resisted the immense strain without any material settlement. Although by this system no new principle is established, yet it may be looked upon as one of the most successful achievements in the science of carpentry, and it has added as much to the science as did the arch to masonry. It has been introduced in many forms, and employed in many ways ; and in every case where a due propriety has been observed in regard to the size of timber employed in the truss, it has given entire satisfaction. But the great simphcity of the theory has, in some cases, led to its abuse ; and as an illustration of this, we have but to refer to a design for an arched roof as constructed by the author of the Builder's Guide, and shown on plate 64 of that work. In this example are two rods, some forty feet long, and they must necessarily be expanded so much by the heat of oux summer as to relieve itself from the strain it is intended to support, so that at times the whole weight must come directly on the tie beams, which would materially loosen the whole truss. We speak of this with all deference to the knowledge and experience of the author, yet we can- not see that the experiment can philosophically rec- ommend itself in a roof of seventy feet span. We are aware that the sanie objection can be brought to a certain degree against the whole theory of substi- tuting rods for the posts ; yet when we take into con- sideration the fact that, in nearly all roofs framed with rods in the ordinary way, the purlines are well sup- ported by the large truss rafter and the collar beam, — that the truss without the rods would, if well executed, almost sustain itself, and that the rods are not only proportionably shorter, but differently applied, — we cannot see that any fears need be entertained in case of the latter, as may be with the former. With a de- gree of propriety, therefore, and an adherence to the principles of strength and support, the new method may be used in an endless variety of ways ; and there is now no reasonable excuse for the uneven roofs which are so often presented to view in many of our churches and other large buildings. — Editors. Plate 86. Fig. A shows how to glue up the head of a niche I'l M |. ©1S9[1©?J3 y®ia !S©©[?3. ihiir s.. Ti..ri i.n l.i Ml I) to 7t) I'l Si. .-Ill . vi.ar, li.w.r Willi Truss I.. !,.>.• il.. n.l.sl.U 1.. lid ri.S|.;iii . StHltiUttl ) i: ■ p V ( J ^' :■' /'/;/. / /f^- /■'it' / ^^tejmLiiiipTr '' STAIRS. 123 the same number of equal parts as here into three. In Fig. 3, make F O equal to one third of/ n, and P Q equal to one third of y 1/ ; join O Q, which pro- duce to meet F P in R. Draw R M, which produce to s. La R s take any point m, and draw m f per- pendicular to R s ; then, parallel to R s, draw A a s, B b r t, C c q 11,1) dp r, E e iv, Ffn x. From Fig. 4 transfer the heights b r, c q, dp, e 0, and / n, to the corresponding lines b r, c q, dp, e o, f n, Fig. 3 ; also, from Fig. 4 transfer the lines a s,rt, q n, p V, o ic, and n x, to a s, r t, q v, p v, ti', and n x, Fig. 3 ; then through the points 11 o p q r a draw a ctirve, which will be the line representing the under edge of the inside falling mould ; also, di-aw the curve X IV V n t s, which is the line representing the upper edge of the same falling mould. The upper and lower edges of the outside falling mould will thus be found — N being the centre of the quadrants B C D E F and G H I K L; draw N E H, N D I, N C K, N B L, cutting the convex side at H, I, K ; and draw H W, I V, K U, L T, parallel to R 5 ; and E W, D V, C U, B T, paraUel to / m. Also, draw s s,tt, ti n, V V, parallel to / m ; and make 1 1, u u, v v, respectively equal to T B, U C, V D ; and complete the parallelogram 1 1, s s, and draw the curve t uv 3, which will meet the curve s t u v tu x at J, the point where a perpendicular drawn from the centre N of the quadrant meets it. In the same manner, find the curve nor; and we shall have the whole projection of the helinet, which will give the thickness of the stuff reqrured to make the rail ; by drawing a straight line iji contact with two points on the under side without cutting the solid, and another parallel to it from the point X, then the distance between these paraUel lines is the thickness of the stuff. ON THE rORMATION OF THE FALLING MOULD. To find tlie falling mould for a semicii'cular stair, with winders round the semicii-cular part ; or the falling mould for a semicu'cular staircase level roimd the semiciixle, joined below and above the fliers. No. 1, Fig. 1, is in the plan of the rail round the circular part, and of a small portion of the straight part with the seats or plans of the risers round the semicircular part. Make a b, No. 2, equal to the height of the wind- ers; draw a c and b d at right angles with a b; make a e and b /each equal to the development oi I p or pm, (No. 1 ; ) draw e I and d k parallel to a b ; make e I and d k each equal to the height of a step ; and join e g- and / k. This description so far applies both to Figs. 1 and 2. Li Fig. 1, No. 2, join c f; make e h equal to e g; and / i equal to f k, and draw the touching curves g-r h and i s k ; and g- r h i s k will be the line of the rail. In Fig. 2, No. 2, produce g- e to t, and k f to u; bisect a b at s, and through 5 draw t u parallel to a c or b d; from g t cut off t iv, and fi-om u k cut off u x, each equal to g- e or / k ; and describe the touching curves g z s and 5 y x, and giv z s y xk will be the line of rail. The breadth of the falling mould in common cases is about two inches ; therefore, di-aw the curve lines each at an inch distance from the line of the rail, and the falling mould will be completed. Plate S8. OX THE RESTING POINTS. PROBLEM. To find the position of the plane of the plank, and the resting points, so that the thickness of stuff required to make the helinet may be the least possible. Fig. 1. Let abed efg h be the plan of the rail, of which the part b c d efg is the quadrant of a cir- cle, and the part a b g h of a rectangular figure ; the straight lines a b and A g being tangents to the outer and inner arcs at b and g, and the circular quadrants bed and g- f e terminated by the radii b I and g I ; then suppose two equal straight lines, one erected upon c and the other upon /, perpendicular to the plane of the plan of the rail, and let c Z be any inter- mediate radius, cutting the interior quadrant at // produce a h and e Ito meet each other in k. Now, if a straight line be supposed to extend from k to the top of the line which stands upon /, the straight line thus extended, if produced, would be higher than the top of the line which stands upon c ; therefore, if a plane pass through a k and through the top of the line insisting upon /, the plane will pass above the top of the line standing upon c, and this will be the case with every section, except the section b g, which is parallel to a k; therefore, if the plane 124 STAIRS. of the plank rest upon the lower section a h, and upon any other two points in the circular part, these points must be in the concave side ; therefore, in this case, the resting points are upon /(,/, e, in the concave side of the rail. Again : in Fig. 2, let I c and a 6 be produced to meet each other in k ; then if a straight line be ex- tended from k to the top of the line which stands upon c, the straight line thus extended, if produced, would be higher than the top of the line which stands upon/; therefore, the plane which passes through a b, and through the top of the line which insists upon c, will be above the point which terminates the top of the line insisting upon /; whence the resting points, a, c, cl, are all upon the convex side of the rail. Lastly : in Fig. 3, if a plane rests upon the top of the two lines insisting upon c and /, and pass through the point a, — and if a line be supposed to stand upon e, perpendicular to the plane of the base, of such a length as to meet the plane which passes through a, and through the upper ends of the lines insisting upon c and /, — it is evident that if another line be supposed to be erected upon d, also perpendicular to the plane of the base and equal in height to the line insisting upon e, the plane wliich passes tlu'ough the point a, and through the tops of the lines insisting upon c,f, e, must be above the top of the line insisting upon d; and that the intersection p q oi the plane passing through a, and the points in the line insisting upon c and/, must be parallel to c /. It is now evident that if a & be produced to r, and h a to 5, and as the intersection always passes tlirough a, the line a p oi the intersection of the plane must al- ways fall withm the right angle r a s. It is likewise evident, if the resting section of the rail fall between c / and a h, as at b g, the middle resting point will be over b in the convex side of the rail ; and if the resting section fall between c / and d e, the resting point of the middle section must be on the concave side. SCHOLIUM I. In stairs constructed upon the letter D plan, with winders in the semicircular part, joined to a series of fliers below and above, where the winders have a higher pitch than the fliers, the first two resting points, beginning at the lowest point, will be on the convex side of the rail, while that at the highest point is on the concave side. Fig. 4. When the lower line of heights is nothing, and the highest double to the middle one, the line of intersection will be found by drawing a line through the seat of the highest and middle resting point, and producing the line on the other side of the seat of the middle resting pomt, until the part produced be equal to the part between the two seats, and drawing a line through the lowest point a, and through the extremity of the point thus found ; then the line thus drawn will be the intersection. Thus, in the present case, a c and e are the resting points ; join c c, and produce e c to A; ; make c k equal to c c, and join a k; then akis the intersection ; and this agrees with what has been observed ; for if a k and Z c be produced, they will meet in ?» ; therefore, / is not the seat of the resting point : if/ were the seat of the restmg point, maldng/ i equal to/ c, and join- ing a i, then a i would be the intersecting line ; but it is not, for the point c is nearer to a m than /. Corollary. — From what has been observed, (see Fig. 5,) that the intersecting line m v never falls within the right angle at o, or upon the plan acdeh, therefore, the point e is always nearer to u v than the point d; therefore, the point e is the seat of a resting point. SCHOLIUM II. Fig. 5. From the same given heights, and from the same three resting sections of the rail, there can- not be more than four intersecting lines by maldng choice of one resting point irom each section. For, suppose we make choice of the points d and c as the seats of the resting points, and join the line d c, and produce d c, suppose to some imaginary point X, and find the point X from the heights upon d and c, in such a manner that the line thus drawn may not cross the plan, even if produced. The same thing may be done through the points d and /, also through the points e and c, and through the pomts e and /; then, whichever of the points, d or e, is near- est to the intersecting line ?f v, that point is the seat of the resting point. With regard to the ratio between the whole line drawn through the seats of the resting points and the part of it between the said seats, it is the same as the ratio between the highest line and the line insisting on the seat of the middle section. Suppose (in Fig. 5) the seats of the resting points are c and r; join c c, and produce it to i; draw e I and c k perpendicular to e i; make e I equal to the SlriJ.3 P' n 1)11 \:- F{^,2. I' t i 3 V S.Ii.ll ,''1 'III STAIRS. 125 height insisting upon e, and c k equal to the height insisting upon c ; join Ik, and produce it to i. Then, because of the similar triangles e i I and c i k, i e : i c : : e I : ck; that is, i c is the same part of i e that c A; is of e I; therefore, if e / be double of c k, e i will be double of c i, or i c will be equal to c e. If the workman should not understand the demon- stration now given, he may proceed mechanically thus, the seats of the resting points being a, c, e. Join e c, and produce ecioi ; draw e I and c k per- pendicular to i e ; make e I equal to the height upon e, c k equal the height upon c ; join I k and produce it to /, and join i a; then i a is the intersecting line. Produce i a both ways to ti and v, cf to o and i', and d e to o and m; di-aw d r, e m, and o q perpendicular to du; draw o p, fia, and c n perpendicular to o v; make c n equal to c k, and join v n; produce v nto p ; mak o q equal to o p, and e m equal to e I; join m q ; then, if m g be produced, it will meet uv in ii. This may easily be conceived by raising the triangles i e I, V p, and u e m, upon their bases, i e, v c, and d u ; then c k will coincide with c n, e I with e m, and o p with o q ; and the lines i 1, v p, and r u will all be in the inclined plane of which its intersection is u V. COXSTRTJCTION OF THE FACE MOULD. Fig. 7. Let a d e f g h i be the plan of the rail, ef g h a portion of the straight part, i being the upper, and/ the lower, resting points. But as the place of the middle resting point d vrSi. affect the tliickjiiess of the stuff, it ought not to be arbitrarily assumed j though it would be diiScult to show upon any prin- ciple where it should be exactly. It is, however, ascertained by trial that its position may vary to a considerable distance without affecting the thickness of the stuiT hi any great degree ; and as experiment shows that it is nearly in the middle of the develop- ment of a d ef, it is here taken in the middle, so that the stretch-out of ad may be equal to the stretch-out of df. Figs. 6 and 7. In the figure of the falling mould, produce the base a e of the winders to /, then a e (Fig. 6) bemg equal to the development of a e, (Fig. 7,) make a d (6) equal to the development of ad, (7,) and make e f (6) equal to e f, (7 ;) draw / 1 parallel to a b, (6,) cutting the upper side of the falling mould at 1, (6 ;) parallel to/a draw I i, cutting a b at i, (6 ;) in i I make i d (6) equal to i d, (7 ;) draw d m (6) par- allel to a b, cutting the upper side of the falling mould at m ; draw vi n parallel to / a, cutting a 6 at n ; draw d r parallel to a b, cutting m n at /•, (G.) Join o r, and produce it to meet i I at q ; make i q (7) equal to iq, (6;) join/ 7, (7,) and produce f q to k i. Through g draw k I perpendicular to k q. Through i draw i z parallel to k q, cutting k I at z. Make z z equal to io, (6 ;) and join k z, (7,) and pro- duce k z tx) I : draw a I parallel to z z. TO FI>rD THE FACE MOTJLD. Fig. 7. Draw I a and z b perpendicular to kl; make I a equal to I a, z i equal to z i, and join i a; then i a will form the part of the face mould repre- sented by i a on the plan. Draw k f perpendicular to k I, and make kf equal to kf. Draw g g parallel to z z, cutting k I 2A, g, and join gf. Again : draw h u parallel to z z, cutting k I at u and k I at tt. Draw w h perpendicular to k I, and make u h equal to uh; draw h e parallel to gf, and/ e parallel to g h ; then e f g h will form the part of the face mould corresponding to the straight part e f gh, in the plan. The intermediate points of the face mould, which form curves of the outside and inside of the rail, are thus found. Through any pomt c, in the convex side of the plan, draw c y parallel to z z, cutting k I at y i, and k I at y, and the concave side of the plan at t. Draw y c perpendicular to k I, and in y c make y t equal to y t, and y c equal to y c ; then tis a. point in the concave side, and c a point in the convex side, of the face mould. A sufficient number of points being thus found, the curved parts of the face mould may be drawn by hand, or by a sfip of wood bent to the curve. It will be perceived that I have been obfiged, in some instances, to use the same letter of reference t«'ice ; but they are so placed, that the one referred to can be ascertained without any difficulty. Plates 89 & 90. REdPROCAL SPIRAL AND SCROLL. To draw the reciprocal spiral for a scroll. Suppose the ordinate q (Fig. 1) to be given. Make a b (Fig. 2) equal to q, and through b draw c d, making an angle with ab ; then take & c in a greater or less ratio to 6 1, as a less or greater part of the scroll is wanted, or as the scroll is required to 126 STAIRS. have a flatter or qmcker curve at the remote extrem- ity ; for instance, b c in this example is double to b 1. Suppose the point c to be now fixed ; draw c e parallel to a b, and a e parallel to c d; make 1, 2; 2, 3 ; 3, 4 ; &c., each equal to b 1, and draw the lines 1 e, 2 e, 3 e, 4 e, &c., cutting a b respectively at e/g", &c. Li Fig. 1, divide the space round the centre o into eight equal angles, which will be easily done by drawing a circle through q, and dividing the circum- ference into eight equal parts, beginning at q ; draw the portions o p, o q, o r, o s, &c. Make o p (Fig. 1) equal to twice a b, (Fig. 2;)oq (Fig. 1) is equal to a b, (Fig. 2;) also, make o r, o s, of, &c., (Fig. 1,) respectively equal to a e, a f, a g, &c., (Fig. 2.) Through all the points p q r s t, &c., draw the curve p q r s t, &c., which will be the spiral required. For want of room, a b (Fig. 2) is only made equal to half the length it ought to have been ; for a & wiU be divided into parts of the same length, whether a b is double and b c equal to b 1, or a b as it is, and b c double of & 1. SCHOLIUM. This spiral is well adapted to the purpose of hand railing, for it may be made close or to extend at pleasure, as may be seen by the subsequent examples. This spiral may be extended so as to form the rail itself by a gentle curve, which will approach nearer to a straight line the more it is extended. The forms of stairs attached to pulpits are often very fanciful ; thek plan requires to be formed in the most graceful manner ; the reciprocal spiral may be applied to this purpose with advantage, as the effect produced will be both beautiful and elegant. It may also be ap- plied to form the plan of the riser of the curtail step into a gentle curve, which will be in perfect unison with the scroll itself. The plans of the other steps may be formed to the same curve ; but the curvature may be made less in each, as the other risers recede from that of the curtail step, till at last the risers be- come straight. The property of this scroll may be shown arithmetically, thus : let any given radius be called unity, or one, and let this radius, so called, be the gi-catest radius ; let « be any constant number, which must be in the same scroll, but variable in difTcrent scrolls, and let a; be a variable number in the same scroll, then will j^_ represent any ordinate ; thus the first, second, third, &c., ordinates, by making x respectively 0, 1, 2, 3, &c., will be respectively By giving n a value, the form of the determined. Thus, make 71 = 2, and _!! ^ &c scroll will be we shall have the series of ordinates, |, f , f , f , |, &c. This will give the scroll Fig. 1, plate 91. Make n^A: then -XI, 4t;, -^,,&c. will become n-f- 1' n + 2' n-j- J' f ) &) I) t, &c., respectively. These are the respective ratios of the ordinates o a, o b,o c,o d,o e, Sec, Fig. 1, plate 88. Lastly : make n = 8; then ;, „-^, ~, ;^,&c.,wm become f , |, j?^^, /j, &c., respectively. These are the respective ratios of the ordinates oa, o b, o c, o d, &c.. Fig. 3, plate 88. So that we have both a geometrical and an arith- metical rule for drawing the reciprocal spiral. It may be here observed that this spiral is the only one that can be employed in forming the volutes of the Corinthian capital. Fig. 3, plate 90, exhibits the scroll with the scale drawn on the first radius. Plate 91. To describe the face and falling mould for pre- paring the scroll. Let a b he the first quarter of the scroll, c the cen- tre ; draw d e parallel to b c, touching the outer spiral at d ; draw e G parallel to c a, and through a draw F G parallel to c b ; make G F equal to the breadth of a step ; di-aw F H perpendicular to G H ; make F H equal to the height of a step, and join H G ; then G H is the pitch line of the stair. Draw lines parallel to a c, cutting the inner edge of the scroll at the points /, g; h, the outer edge at i, k, I, m, n, the straight line F G in the points n, o, p, q, r, and H G at the points N, O, P, Q, R ; let a c cut the concave side of the scroll at t, and let it be produced to cut H G at A ; from the point //, where the line d c cuts the concave spiral of the scroll, draw h W parallel to a c, cutting A G at W, F G at r, and the con- vex spiral at ?/. Draw W H and G E perpendicular to II G. Make W H and G E each equal to v h or G e, and join H E ; through the points N, O, P, Q, R, draw lines perpendicidar to H G ; in the perpendicu- lars make AT, N F, O G, each respectively equal to a, t, n, f, o,g; also, make N I, O K, P L, Q, M, R N, each respectively to « i, k, p 1, q m, r n ; draw T X paraUel to H G, and draw the curves T F G H ■jBaE ri.:n .- iM'4i)|i!)|].[g> i?®(B iroas iS©a®[ULo aif-pfLo^inro^Ri ®[? Trsaig im.ss sa®aj(L©. I'l.'ij ®'ii3 iriME i?a!>[aQ]i\ifa(d)S3 ®i? vboe svisara©. Pi.y.i F,<,. 2 7 '^ ,/ f // / / / • f ''V u - /. L f fXi h "^ ^ STAIRS. 127 and A I K L M N E, which will complete the face mould for the twisted part of the scroll, which is to be glued to the other part formed in one level piece. The falling mould is constructed as follows : Fig. 2. Let F G H be the pitch board, as in Fig. 1. Divide F G into eight equal parts, and make F a equal to three of the parts ; through a di'aw d q perpendicular to F G, cutting H G at ^ ; produce H G io d; draw any line q s parallel to F G, and make q s equal to the sti'ctcli out of the first two quarters, a, b, v, of the outward spiral. Fig. 1 ; through s draw u d parallel to H F ; in H d take any distance d b, and draw b a parallel to F G, cutting u d at a. Again : in H d take b c equal to b a, and join c a; through ^j draw p t parallel to c a, cutting n b in t ; draw t v parallel to F G, cutting H fZ at w ; then will v t ha equal to V p; divide v p and v t each into the same number of equal parts, and draw the intersecting lines to the points of division, and the curves formed will be the upper edge of the falling mould ; the other edge will be formed by gauging off the thickness of the rail. Plate 92. APPLICATION OF THE FACE MOULD TO THE PLANK. To form the figure of tlie face mould upon each side of the plank, so that, when the super- fluous wood is cut away, the carved surfaces formed thereby may stand perpendicular to the plan, supposing the piece thus formed set in due position. Let abed e f g be the Fig. 1 of the face mould, placed in due position to the pitch line g i, as when traced from the plan ; and let Fig. 2 represent a de- velopment of the plank where X represents the top, Y the edge, and Z the under side of the plank. The face mould is first applied to the top X, so that the points g and the chord line g e oi the mould may make the same angle at g with the arris line g e of the plank that the figure of the mould at Fig. 1 makes with the pitch line ; di-aw g K, making the same angle with i g that the pitch line makes with any connecting line or perpendicular, and draw the figure of the mould on the plank ; apply the same mould to the other side Z of the plank to the point K, so that the chord may make the same angle with the other arris as on the first side, and draw the fig- ure of the mould on this last side ; then the soUd which is formed by cutting away the superfluous wood is the piece required. But as it may be desirable to apply the tips of the mould g and e close to the edge of the plank. Fig. 3 shows how the plank is to be lined out according to this application. Here the pitch line g K makes the same angle with the upper arris of the plank as be- fore ; di-aw g L perpendicular to either arris, cutting the lower arris at L ; make the angle K L G equal to the angle e g i, Fig. 1 ; make L g equal to L K, and draw the chord g" e, in the plane Z, parallel to the arris line ; in the plane Z apply the tips g and e of the face mould to the line g e, as exhibited in the figure ; then draw the form of the face mould as before. DEMONSTRATION. Fig. 2. Draw g L in the plane Y, cutting the lower arris of the plank at L ; draw the ciiord K e of the face mould in the plane Z, and draw L M in the same plane parallel to K e ; also draw L s perpendicular to K e, cutting K e at s. Now, imagine the figure M L K e to be moved so as to revolve on the point L, until L M come into the arris L m; it is evident that the point K will move in the circumference of the circle K k, and wiU come into the position k ; and that the angle K L A* will be equal to the angle »i L M ; but the angle 7ii L M is equal to the angle agi, Fig. 1. Again : reverting to Figs. 2 and 3, it is plain in Fig. 3, that if the angle KTi g in the plane Z be made equal to the angle e g i, Fig. 1, and if L g- be made equal to L K, and the mould applied to each side of the plank as in the figure, the solid, when cut out, by taking away the superfluous wood, will be equal and similar in all its corresponding parts to that cut out according to the oblique chords. Fig. 2. Fig. 4 shows another application where the chord of the face mould is neither applied to the angle e g i, nor paraUel to the arris lines ; but as this application is rather curious than useful, the bare inspection of the diagram wiU render it sufficiently clear to those who will take the trouble to consider it. Plate 93. ON THE FORMATION OF THE STRING. PROBLEM. To form the soffit of a stair with easings at the junctions of the fliers and winders. Let Fig. 1 be the plan of the staur, the breadth of 128 STAIRS. the steps being divided equally along the middle line. Suppose the winders to begin at riser C, and let the string from the riser of the curtail step to the point C be straight. The first thing to be done is to stretch out the string; but in this development it will not be neces- sary to exhibit it entirely, the circular part and a small portion of the straight part at each end will be suffi- cient; therefore, beginning at A, we shall take in the two fliers over A B and B C. In Fig. 2, draw;? I parallel to the rail, and makep I equal to the length of tlie line abed e f g h. Draw I K perpendicular to p I, make 1 1 ; 1, 2 ; 2, 3 ; equal to tlie heights of the three risers over ABC, Fig. 1 ; also, in Fig. 2, make 3, 4 ; 4, 5 ; 5, 6 ; 6,7; 7, 8 ; each equal to the height of the winders over D, E, F, G, H. h\ the plan Fig. 1, suppose a line drawn tlirough the centre x perpendicular to the rail, cutting the mid- dle line at D, and let this line be produced to ?;, Fig. 2 ; in Fig. 2, draw 3 c parallel to p I, cutting xuatu; join up and m 7 ; draw^j a in the same straight line with the riser A, b b in the same straight line with the riser B, and c c in the same straight line with the riser C, to cut p ti at b and q ; make ti r equal to u q, then form the easing curve q r ; draw 2 c, i d, 5 c, €/, 7 g; parallel to^ I, cutting the easing curve at d and e, and m 7 at / and g ; draw d d, e e, f f, g g^ parallel to I K ; make c d equal to c d, d e equal to d e, e/ equal to ef, fg equal to fg, and g h equal to g h; then D H being divided into equal parts at the points E, F, G, join D d, E e, F/, G g-, and pro- duce them to the wall line ; in Fig. 2, draw the curve P Q, R parallel to p q r zt a proper distance, which completes one half of the string. The manner of completing the other half is evident. OBSERVATIONS. Having given the details of finishing, I shall now proceed to offer a few general remarks in relation to this subject. The selecting of biiilding materials has not, in gen- eral, received that care and attention wliich this im- portant subject demands. Many buildings have been ruined, the owners of others have been displeased, and not without just cause ; and the workman has lost his reputation, and forfeited his claim to public patron- age, solely firom neglect in this important particidar. The first care of a master builder should be to see that his lumber is properly seasoned. The best method of seasoning is, after boards or plank have been sawed at the mills, they should be immersed in salt or fresh water for the space of one or two months ; larger lumber should remain in this situation till the sap is properly extracted from tlie wood ; this opera- tion preserves the lumber in some degree fi-om the dry rot. Next take the boards or plank out of the water, and pile them in a situation where the air may have a free circulation through and on all sides of the piles. They should remain in this situation for one year ; then take them down and select such as are suitable for finishing : these should again be stuck in a buUding, or covered in such a manner as to be secure from the weather ; they should remain in this situation at least sLx months before they are used. While preparing the stuff for finishing, it should be spread to the sun every fair day, and put under cover at night for three or four weeks before it is put together. The mechanic will feel himself well paid for his time and trouble when he shall examine his work at any subsequent period. Framing timber should be squared up soon after being taken out of the water, and stuck up under cover for the space of six months before it is worked into buUdings ; this wUl correct the erroneous idea, in many cases, where the settling of the floor has been attributed to bad workmanship, when, in fact, it has been occasioned by the shrinking of the timber. The Idnd of lumber in general use for building in the New England States is white, yellow, pitch, and Norway pine ; spruce, cedar, and sometimes hemlock, white and basswood. The hard woods are oak, ma- hogany, maple, cherry, and ash. In the Southern States there is found a superior species of pine, which, for durability, is preferable to northern pine, when used for floor boards or joists. Pine boards and joists are sorted into different qualities, known as Nos. 1, 2, and 3. No. 1 is square edged, free from knots, shakes, and rot. No. 2, the second quality, is sound, not entirely free from knots, and is square edged. No. 3 has Imots, shakes, is wane edged, and has some rot. No. 1 is used for the best of finishing ; No. 2 for rough boarding, such as roofs, side and end boarding, &:c., where the edges are re- quired to be tongucd and grooved, or rabbeted. From this quality, by properly sorting them, good floor boards may be selected, which should be sawed from four to seven inches wide ; many of them will be clear, and, after they arc A^TOught to a thickness, the clearest may be used for the best rooms, and the others as they may be suitable for the different rooms. I'l.'.ll :0®Mav(aaj)©"/uiS.'>( £■/ . r.i3 Ls3iauic)®a:, liv llliii'l MV f'lal I t=lR B-B I Jj U \/\/\/\/\/\/^\A\/\/\/\/ \/\/ \/\/ \/ \ /\ / /\/ \/\ /\ /\/\ /\ '/ v/ y\v/y ^xxv\^/\Vx/\//\ y\ /\ /\ /\ /\ x\ /\ /\/a\ //'\\ \\/./w \xy \.y\ /\-^^ "TT" T-^T^ /;>/ ?. T=^Tli^TT;ii-rp- 11 — '1— II- ii— II-- \\=^^ir- ,K' 1 1 I 'I -^K I I II II 'I yk i| 1 1 T" ::?T :l \il .1 il iA.JL_ l^ I \l I -_IL,_J___"T y\ I r\ I _IL JJ .TT XTT TTTT H JT I .K II II 11 .y\ \Z1 ■iJ 1_XLI T7- II IIVJ,1 fT T~^a _,JJ.__Tr71l ;J IJvll II \l'/Zl __.■! _- i| II II K ' r ] ,^__-U jz: 1L II ^.ILn -Ji-:l- "X" / I ,_!1,__ 11 H_\ 'IV I __[!: 1 r ,\ V^M^ \V~1L. sxz ;l-lLr-J L^— I— ),-^,ll-^ II— NK— TT =Sp= it: IT l2F^ J,_- IJ I ^ x~^T — ..;[.. .JL -_LI^ZlJ\_,iL~ir y.K-TLI-JJL II II II /'l\ II 1! II 1/- -Nl, II iJ,_ II \V_,\\_\\ II \/ n ML _,rn:7:LLVL^i/__ii^ Ni_ _J_ ll ,>il II IK II rt^~ ii ,1 ^1 'T r IXTT ^U U ^L__ II l|\"T~ \ wy II n ""^3: il II II II ':|\ V~r 7r:T' iK~ir _ll/„il 3SI il II Ml IT II II Mv II ,_ii__ii.__jL~::T3J TT v^c lie I L II V I BRIDGES. 129 BRIDGES. Mr. Ithiel To\vn's improvement in the construction of bridges being considered preferable to any mode of bridge building yet laid before the public, it has been thought best, in this department of the work, to give his arguments and description in his own words, and to refer the reader to the introduction for such additional facts and remarks as has been thought necessary to lay before him, in order to give him a more perfect understanding of this important branch of his profession. Plate 94 A Description of Ithiel Toioi's Improvement in the Construction of icooden and iron Bridges., intended as a general System of Bridge Building for Rivers, Creeks, and Harbors, of whatever Kind of Bottoms, and for ani/ practicable Width of Span or Opening, in every Part of the Country. To establish a general mode of constructing wooden and iron bridges, and which mode of con- struction shall, at the same time, be the most simple, permanent, and economical, both in erecting and repairing, has been for a long time a desideratum of great importance to a country so extensive, and in- terspersed with so many wild and majestic rivers as ours is. It has been too much the custom for archi- tects and builders to pUe together materials, each according to his own ideas of the scientific principles and practice of bridge building, and the result has been, first, that nearly as many modes of construc- tion have becH adopted as there have been bridges built ; second, that many have answered no purpose at all, and others but very poorly and for a short time ; while most of the best ones have cost a sura which deters and puts it out of the power of probably five sixths of those interested in ferries to substitute bridges which would obviate the many dangers and delays incident to them. That architects and builders adhere to their own ideas in the construction not only of bridges, but of buildings, is most universally true. They are obsti- nately opposed to the adoption of any other mode than their own ; consequently it is true, and it is seen to be so throughout the country, (and it is much to be regretted,) that in very few instances, either in erecting bridges or buildings, there is any model, 17 either uniform or in genera!, very good. But in bridges and public buildings, it would .seem some- thing better might be expected if men scientifically and practically acquainted with such subject.s would step forward in a disinterested manner, and deter- mine between principles which arc philosophical and those which ase not, and between modes of execution which are founded in practice and experience and those which are founded in ignorance and inexperi- ence ; and in matters of taste, if they would deter- mine in favor of classic and well-established usage, and not that which is the offspring of unimproved minds and whimsical fancies, which are ever upon the rack to establish new things — the creation of their own imaginations, and which are, therefore, sure to be wrong, for this good reason — that their authors are so. Perhaps the following propoeition comprises what is the most important to be determined with regard to a general system of bridge building, viz. : — By what construction or arrangement will the least quantity of materials and cost of labor erect a bridge of any practicable span or opening between piers or abutments, to be the strongest and most per- manent, and to admit of the easiest repair. In giving the best answer to this proposition which I am capable of after a number of years' attention to the theory and practice of this subject, I shall refer to plate 94. The mode of construction is so simple and plain to inspection as to require little explanation of it. Fig. 3 is an elevation of one of the trusses of a bridge ; one, two, or three of those trusses placed vertically upon piers are to be considered as the sup- port of the bridge, and are to be of a height, at least, sufficient to admit a wagon to pass under the upper beams which lie horizontally upon the top string piece of the side trusses ; and on these same side string pieces rest the feet of rafters, which form a roof to shingle upon. In this case a middle truss is used, which will always be necessary in bridges of considerable width. The height of it wiU be as much greater than the side ones as the height or pitch of the roof. The height of the trusses must 130 BRIDGES. be equal to the whole height of the bridge required, and is to be an exact continuation of the work represented in Fig. 1. The height of the trusses is to be proportioned to the width of the openings between the piers or abutments, and may be about one tenth of the open- ings, when the piers arc fifteen feet or more apart — a less span requiring about the same height, for the reasons before stated. The diagonal bearing of these trusses is composed of sawed plank, ten or eleven inches wide, and from three to three and a half inches thick. It may be sawed from any timber that will last well when kept dry. White pine and spruce are probably the best kinds of timber for the purpose, on account of their lightness, and their not being so subject to spring or warp as white oak. The nearer those braces are placed to each other, the more strength will the truss have, and in no case are they to be halved or gained where they intersect each other ; but they are to stand in close contact, depending entirely on three or four trunnels which go through each joint or intersection; and where the string pieces pass over these joints, the trunnels go through them also, and are each of them wedged at each end to keep the timber in close contact. A chain or clamp is necessary to bring the work tight together. Trunnels may be made of white oak, one and a half inches in diameter. They are made very cheaply and excellently by being rived out square, and driven, while green or wet, through a tube fitted to a block, and ground to an edge at the top end. They are then to be seasoned before they are used. The string pieces arc composed of two thicknesses of plank, of about the same dimensions as the braces, and they arc so put together as to break joints, as shown at Fig. 4. This renders long-hewn timber iinnecessary, as also any labor in making splices and putting on iron work. For any span or opening not exceeding one hun- dred and thirty feet, one string piece at top and one at bottom of each truss, if of a good proportion and well secured, will be sufTicicnt ; but as the span is extended beyond one hundred and thirty feet, two or more at top and bottom would be required, as shown in Fig. 1, where two string pieces run over the two upper and lower series of joists or intersections of the braces : and in wide spans the floor beams may be placed on the second string piece, as shown at Fig. 1. Fig. 5 shows, on a larger scale, how each joint is secured, by which it is seen that the trunnels take hold of the whole thickness of each piece. Fig. 4 is a section of a bridge of this construction, and shows the manner in which the braces and string pieces come together, and also the manner of making the floor of the bridge, and of butting beams and braces over head, which are to be connected with the middle truss for the purpose of bracing the bridge against lateral rack or motion. Very flat- pitched roofs will be preferable, as- they will, in that case, be a greater support to the upper part of the bridge. a a a a, Fig. 1, show the elevation of the roof. Fig. 2 is the floor or plan of the bridge, showing the mode of bracing and the floor joist. Fig. 4 is a view of the bottom or top edge of the string piece, and shows how the joints are broken in using the plank, and also how the trunnels are dis- turbed. This mode of construction will have the same advantages in iron as in wood, and some in cast iron which wood has not, viz., that of reducing the braces in size between the joints, and of cast- ing flaunches to them where they intersect, thereby making it unnecessary to have more than one bolt and nut to each joint or intersection. When it is considered that bridges, covered from the weather, will last seven or eight times as long as those not covered, and that the cheapness of this mode will admit of its being generally adopted, with openings or spans between piers composed of piles, and at a distance of one hundred and twenty to one hundred and sixty feet apart, then the construction of long bridges over mud-bottomed rivers, like those at Washington, Boston, Norfolk, Charleston, &c., wiU be perceived to be of great importance, especially as the common mode of piling is so exposed to freshets, uncommon tides, driftwood, and ice, as not to insure safety or economy in covering them, and, conse- quently, continual repairs, and often rebuilding them, become necessary. There is very little, if any, doubt that one half of the expense, computing stock and interest, that would be required to keep up, for one hundred years, one of the common pile bridges, like those at Boston, would be sufficient to maintain one built in this new mode, keep it covered, and have all BRIDGES. 131 or nearly all, the piers built with stone at the end of the one hundred years. If this be the case, it would be great economy to commence rebuilding, by de- grees, in this manner. The saving in the one article of floor planks, if kept dry, would be very great, as, by being so much wet, they rot and wear out in about hair the time. For aqueduct bridges of wood or iron, no other mode can be as cheap or answer as well. This mode has equal advantages also in supporting wide roofs of buildings, centres of wide arches in masonry, trussed floorings, partitions, sides of wood towers, steeples, &c., 6cc., of public buildings, as it requires nothing more than common planks, instead of long timber — being much cheaper, easier to raise, less subject to wet or dry rot, and requiring no iron work. Some of the advantages of constructing bridges according to this mode are the following: — 1. There is no pressure against abutments or piers, as arched bridges have, and, consequently, perpendic- ular supports only are necessary : this saving in wide arches is very great, sometimes equal to a third part of the whole expense of the bridge. 2. The shrinking of timber has little or no effect, as the strain upon each plank of the trusses, both of the braces and string pieces, is an end-grain strain or lengthwise of the wood. 3. Suitable timber can be easily procured and sawed at common mills, as it requires no large or long timber ; defects in timber may be discovered, and wet and dry rot prevented, much more easily than could be m large timber. 4. There is no iron work required, — which, at best, is not safe, — especially in frosty weather. 5. It has less motion than is common in bridges, and which is so injurious and frequently fatal to bridges ; and, being in a horizontal line, is much less operated upon by winds. 6. A level road way is among the most important advantages of this mode of construction. 7. The side trusses serve as a frame to cover upon, and thereby save any extra weight of timber, except the covering itself; and the importance and economy of covering bridges from the weather is too well un- derstood to need recommendation after the experi- ence which this country has already had. 8. Draws for shipping to pass through may with perfect safety be introduced in any part of the bridge without weakening, as in arched bridges, where llu' strength and safety of the arches depend so much on their pressure against each other and abutments, tiiat a draw, by destroying the connection, weakens the whole superstructure. 9. The great number of nearly equal parts ov joints into which the strain, occasioned by a great weight upon the bridge, is divided, is a very important ad- vantage over any other mode, as, by dividing!; the strain or stress into so many parts, that which falls upon any one part or joint is easily sustained by it without either the mode of securing the joints, or the strength of the materials being sufficient. 10. The expense of the superstructure of a bridge would not be more than from one half to two thirds of other modes of constructing one over the same span or opening. This is a very important considera- tion, especially in the Southern and Western States, where there are many wide rivers, and a very scat- tered population to defray the expenses of bridges. 11. This mode of securing the braces by so many trunnels gives them much more strength when they are in tension strain than could be had in the com- mon mode of securing them by means of tenons and mortises ; for tenons being short, and not very thick, compared with this mode, nor having so much hold of the pins or trunnels as in this case, will, of course, have much less power to sustain a tension or pulling strain ; and it is obvious that this strain is in many cases equal to, and in others greater than, the thrust or pushing strain. It is also very obvious that this pushing or thrust strain in the mode of tenons and mortises receives very little additional strength from the shoulders of the tenons, as the shrinkage of the timber into which the tenon goes is generally so much as to let the work settle so far as to give a motion or vibration, which, in time, renders them weak and insufficient. 12. Should any kind of arched bridge, for any rea- son, be preferred, however, it may be arched either at top or bottom, or both ; still this same mode of com- bining the materials will have all the advantages, as to cheapness and strength, over the common ones of framing, as in the case of the horizontal or straight ones before described. Li cases where abutments are already built, it may sometimes be preferred. Sidewalks may with equal ease be constructed, either on the outside or inside of the main body of 132 BRIDGES. the bridge, which particular, us also the great strength of the mode, &c., may be better seen by examination of the models, which are, or soon will be, placed in most of the principal cities of the United States; and no merit is either desired or claimed in this new mode of construction by the patentee which the mode itself docs not command, even on the most strict philosophical investigation, as to its mathematical principles, the easy, practicable, and advantageous application of materials, the advantages it possesses in mechanical execution, and its simplicity, strength, economy, and durability, as a general and uniform mode of bridge building. Science and practice will, in a short time, decide on this question, so important to this extensive country. I shall conclude this article by a few ideas taken from the celebrated Robert Fulton's Treatise on Ca- nal Navigation, page 117 and subsequent pages. In England, the attention of engineers has, of late years, been much engaged on bridges of iron. These bridges, as experience produces courage, are progres- sively enlarging their dimensions ; nor should I be surprised if genius should, in time, produce the me- chanic rainbow of one thousand feet over wide and rapid rivers. Li crossing the rivers in such countries as Russia and America, an extensive arch seems to be a consideration of the first importance, as the riv- ers, or even rivulets, in time of rain, suddenly swell to a great height ; and in the spring, on breaking up of ice, the immense quantity which is borne down with a rapid stream would, if interrupted by small arches and piers, collect to such a weight as ulti- mately to bear away the whole. It is, therefore, ne- cessary that, in such situations, an arch should be extended as far as possible, and so high as to suffer every thing to pass through, or the inhabitants must, without some other expedient, submit their passage to the casualties of the weather. The important objection to bridges of wood is their rapid decay ; and this objection is certainly well founded when particular situations are alluded to where timber is scarce, and, consequently, expensive. But in such countries as America, where wood is abimdant, I conceive it will be a fair criterion to judge of their application by calculating on the ex- pense of a bridge of stone and one of wood, and then compare the interest of the principal saved in adopting the wood bridge with the expense of its annual repairs. I have before exhibited the necessity of construct- ing bridges in America of an extensive span or arch, in order to suffer the ice and collected waters to pass without interruption ; and for this purpose, it must be observed that a wood arch may be formed of a much greater length or span than it is possible to erect one of stone : hence wooden bridges are appli- cable to many situations where accumulated waters, bearing down trees and fields of ice, would tear a bridge of stone from its foundation. It therefore becomes of importance to render bridges of wood as permanent as the natm'e of the material will admit. Hitherto, in bridges not covered from the weather, the immense quantity of mortises and tenons, which, however well done, will admit air and wet, and, con- sequently, tend to expedite the decay of the weak parts, has been a material error in constructing bridges of wood. But to render wood bridges of much more impor- tance than they have hitherto been considered — first, from their extensive span ; secondly, from their dura- bility — two things must be considered: first, that the woodworks should stand clear of the stream in every part, by which it never would have any other weight to sustain than that of the usual carriages ; secondly, that it will be so combined as to exclude, as much as possible, the air and rain. When the true principle of building bridges of wood is discovered, their progressive extension is as reasonable as the increased dimensions of shipping, which, in early ages, was deemed a great work, if they amomited to one hundred tons' burden ; but time and experience have extended the art of ship building to two thousand tons, and in the combina- tion and arrangement of the various and complicated parts there certainly is more genius and labor re- quired than in erecting a bridge of five hundred or one thousand feet span. But the great demand for shipping has rendered their formation familiar, and their increased bulk has gradually grown upon our senses. But had a man, in the infancy of naval architecture, hinted at a vessel of two thousand tons, I am inclined to think his contemporary artists would have branded him as a madman. SecliL.ii.3h.iviin.lli.> ■ciiislriuii.)!. .M ilif Ari-hi'S .itir (■i-iiumiui)- Hi y-M. / \: I -"Timmm: \mmm. pmrnmi^r,:^ pmmn i^ m^ ^mm:\^-^:j^^ ?T? fT? ffTi rCO Sr3 f^^ rzT, ,'>1 ' 7T- I.' I'j'. '01 ''ff_ ■'J ■/ ' ■ 7 3. F,y.2. -^ ■■IS'Jfl/tlf/im Sf BRIDGES. 133 WATERLOO BRIDGE. Plate 95. This bridge, thrown over the River Thames, at London, was projected by Mr. George Dodd, about the year 1805. Considerable time, however, elapsed before the iiltimate arrangements necessary to carry it into execution were made. The first act was ob- tained in the month of June, 1809, and incorporated the proprietors under the name of the " Strand Bridge Company," empowering them to raise the sum of £500,000 in transferrable shares of £100 each ; and the further sum of £300,000, by the issuing new shares, or by mortgage, in case it should be found necessary. In July, 1813, a second act was passed, enabling them to raise an additional sum of £200,000 ; and in July, 1816, a third act was obtained, granting the company further powers, and changing the name from Strand Bridge to Waterloo Bridge, which name it now bears. IVIr. Rennie, having been appointed engineer to the company on the 23d day of June, 1810, furnished two designs, one of seven and the other of nine arches, the latter of which was finally approved by the com- mittee and ordered to be put in execution. This noble bridge is situated about half way be- tween the Bridges of Blackfriars and Westminster. The river at this place is about 1326 feet wide at high water ; and ordinary spring tides rise about 13 feet, and ordinary neap tides about 9 feet 6 inches. The greatest depth at low water is about 9 feet. The bed of the river is composed principally of a stratum of sand and gravel resting upon clay. The bridge is level, and consists of nine semi-ellip- tical arches, each having a span of 120 feet, and a rise of 35 feet ; thus leaving for the navigation 30 feet of clear height above the high water of spring tides, and forming an ample water way of 1080 feet. The abutments are 40 feet thick at the bases, and diminish to 30 feet at the springing of the arches. Their lengths, including the stairs, are 140 feet. The piers are 30 feet broad at the base, and diminish to tw^o thirds at the springing of the arches. Their lengths at the bases are 87 feet. The points or sa- lient angles of the piers are in the form of a Gothic arch, and are terminated above by two three-quarter columns, supporting an entablature which forms a recess. The whole is surmounted with a balustrade and a frieze and cornice of the Grecian Doric. The columns are Doric also, and were selected on account of the extraordinary strength of their proportions, as being best suited to a structure of this magnitude : they are 23 feet 9 inches high, or, rather, more than four diameters. The clear width between the parapets is 42 feet 4 inches, allowing 28 feet 4 inches for the carriage-way, and 7 feet for each of the footpaths. Four plying places, or stairs, for watermen, are formed by circular wings, projecting at right angles to the bridge, with archways leading to the road way. These wings are ornamented with columns, entabla- tures, &c., as before described. The bridge being level, and of so great a length, it became necessary to provide means for carrying off the rain water. This is efiectcd by having circular openings in the centre of each pier, which enter the river immediately below low-water mark ; these open- ings are connected with iron branch pipes up to the level of the road-way, where gratings are placed to receive the water. The roads, or approaches, to each end of the pier are 70 feet wide throughout, except just at the en- trance into the Strand, and are carried over a series of semicircular brick arches of 16 feet span each. The Surry, or southern approach, is formed by 39 of these, besides an elliptical arch of 26 feet span over the narrow wall road, and a small embankment about 165 yards long, having an easy and gradual ascent of not more than 1 foot in 34 feet. Feet. The length of the brick arches in the Surry approach is 766 Ditto of those in the Strand approach, . . 310 Total length of the bridge from the ends of the abutments, 1380 Total length of the bridge and brick arches, 2456 Fig. 1 exhibits a longitudinal section of one of the arches, the adjacent piers, and part of the next adja- cent arches, with the elevation of one of the trusses forming the centre. The curve of equilibrium passes through the middle of the length of the arch stones, or very nearly so. The hollows over the piers are raised to the level of the summits of the arches by parallel brick walls, and connected with blocks of stone from wall to wall, for supporting the road-way. The centring was composed of eight trusses. It is 1250 feet long, has nine elliptical arches of 120 feet 134 RURAL VILLA.— CHURCH EDIFICE. span over the river, with piers 20 feet thick, built en- tirely of granite, and forty brick arches for a cause- way on the Surry side. This plate is given with a view of showing the construction of masonry, as gen- erally applied to bridge building. The geometrical principle of constructing arches, and drawing the joint Lines so as to be perpendicular to the curve, is sufficiently explained in plate 101. Fig. 2. The horizontal section showing the brick walls, as a, a, &c., which arc covered with stone ; also, the foundation of the piers at b, b, &c. RURAL VILLA AT MILFORD, MASS. Plate 96. On this plate we have given a front elevation, with a transverse section, together with the entrance and chamber-story plans of a villa that we have erected during the past year, in the town of MUford, Mass., for A. C. Mayhew, Esq. It was our intention at first to place at the last part of this work a series of six designs for buildings of this character, with their plans and detailg ; but upon further consideration we have concluded to omit them, and, at some future time, publish them in a form more in keeping with a work of a rural character; this plate, however, being made, we have inserted it as plate 96. The size of the building will be readily seen by the figures on the drawing. The outside walls are of hard-burnt bricks, and are twelve inches in thickness, which are vaulted, or having an air space of four inches between the exterior and inte- rior courses. The angles of the buUding are laid solid, as are also the sides of the openings in the walls, such as the sides of the doors, windows, &e. The vaulted portions are connected together by means of ties of brick in every two feet in length. The exterior walls are covered with stucco cement, and colored in imitation of drab stone. The exte- rior wood work is painted, and sanded with beach sand. — Editors. CHURCH EDIFICE AT MILFORD, MASS. Plate 97. On this plate will be found the t%vo plans, and the front elevation of a small church which was erected under our superintendence in 1850, for the Pearl Street Universalist Society of JMilford, Mass. We do not present it as containing any thing of pecu- liar merit or of costly design ; but the arrangement of the plans and tlie general features of the build- ing having received the approval and approbation of building committees and others interested in such matters, we have, at their urgent solicitations, and at the suggestions of many others, inserted this plate for the benefit of those seeking the information the plate and its description may contain. The fol- lowing description of this edifice appeared in the Trumpet and Universalist Magazine at the time the budding was dedicated ; and, with a few slight alter- ations, we transcribe it entire, as the description of plate 97.* ARCHITECTURAL DESCRIPTION OF THE NEW MEET- ING-HOUSE IN MILrORD, IIASS. This building is built of wood, erected upon a brick stylobate or basement, and is of the following dimensions, viz., length, 72 feet 8 inches; width, 51 feet, outside; with a projecting vestibule on the front end, 13 feet wide by 26 feet long, and the posts are 25 feet in height. Upon the roof of the vestibule stands a pedestal, 19 feet square and 13 feet high, finished with suitable projections ; upon this is a clock tablet, 15 feet square and 12 feet high, covered with a roof showing an entablature and pediment on each side ; the tab- let is finished with heavy mouldings, and a recess 8 inches deep is made on each side, to receive a dial 7 feet in diameter. Rising from this is an octagonal bell tower, 12 feet in diameter and IG feet high, including its base and entablature ; on each of its sides are arched openings, 3 feet 3 inches in width, and in each of which is a balus- trade, composed of heavy-turned balusters. Upon this tower is an octagonal pedestal, 6 feet high and 11 feet in diameter, with deep panels on each side, which is surmounted by a spire 45 feet high, crowned with a carved finial, making the entire height from the line of the grading 136 feet. The style of architecture Is the Roman- esque, which is a combination of the Roman and the late Norman, the latter being the prevailing style of the 11th century. The cor- ners of the building, together with the vestibule, are finished with heavy pUasters 2 feet 9 inches wide, in each of which is a deep circular-headed panel ; upon these rests a dentil corniced entablature, 5 feet deep. The cornice of the entablature is continued up the rakes of the main building and vestibule, which finish gives the whole an imposing and massive appearance. The building is Ughted on either side by three circular-headed win- dows, which arc composed of two circular-headed parts, and separated by a large mullion ; and the front of the main building, on either side of the vestibule, by one of the same style, and of two thirds the width * To OUn BELOVED FRIENU, THE ReV. HeNRT A. EaTON, PAS- TOR OP TUE SOCIETY, AND UNDER WHOSE MINISTRATIONS TUB BUILDING WAS ERECTED, THIS PLATE IS RESPECTFULLY DEDI- CATED, A3 A SMALL TRIBUTE OF RESPECT AND ESTEEM, BY THE ARCHITECTS. THOMAS W. SILLOWAY, GEORGE M. HARDING. ri.iii ;r: J a- J L Ji i- :z3 L vaza'j ] •//; . a L :^=za =11 i^ =a :3 -4 :^ -1-^ />•///.,/•.// /,/,//,//,., //,/// I I 1 I 1 1 [/»< i:„ll,r\ ■izn.li- II 1 ! •^■"■■f ' H =2 ' « V ■ -Jen,- ...J^? (o) J'ltrs-tit/r ■BSg S^^^SS FIhti of Prinripnl Floor Han & From Elevation (ti a .Snih- I't'Jfi ft to on uich fl. ihniry t'l.ill ..I \.',M( \ I I, I. S(/^f>wt7r A 'A^jrf//f/^. Mf£. CHURCH EDIFICE. of those on the sides, making them adapted to their location. The choir-room, which is on the second floor of the vestibule, is lighted by a largo window, composed of one in its centre, similar to those before described ; to which is added on either, side another of one half its width, and a proportionate height, and separated from it by pilasters, the capitals of which are so disposed that the centre ■win- dow is stilted 1 foot 6 inches ; the i\idth of the entire window is 1 1 feet. Beneath this window, on the front of the vestibule, is the main entrance to the building, which is by three circular-headed doors, the centre one of which is 5 feet wide suid 13A feet high ; the arch of this door is stilted 3 feet. Those of cither side are 34 feet wide and 10 feet 3 inches high; making an actual space in width of 12 feet, which is 1 foot 6 inches more than the whole width of the church aisles. The doors are entered by five steps, which are buUt of southern pine, and extend the entire length of the vestibule, in- cluding a buttress 3 feet wide at either end. This brings us to the interior of the building. As has been before stated, the entrance was but five steps from the grading on the front end, so that the entrance floor is five feet lower than the pew floor ; a space of four feet is left at the entrance on the inside, the entire length of the vestibule, 24 feet. And at that distance from the doors, a flight of eight stairs, 13 feet long, lead up to the entry of the church ; which entry is 74 feet wide, and runs the entire width of the church on the inside. These stairs are very easy of ascent, and, being 13 feet long, amoimt to 24 feet more than the width of all the aisles, so that these, together with the outside doors, insure against any jam being produced in the entry of the building, which is one of the evUs with which the architect has often to contend. On either side of the main stairs to the church arc those leading to the vestry ; these are each 44 feet wide, making a passage-way of 9 feet ; they are built of southern pine, as are also the floors of all the entries, and are oiled over, leaving the natural color of the wood. A large mahogany rail and southern pine balusters com- mence at the foot of those to the vestry, and are continued up around the well-room over those to the church, and returns at the top railing in the space on the upper entry, which is not occupied by those leading to the entrance floor. An arch is sprung over each of the three openings at the top of the church stairs ; these openings are made by a square pillar coming down at the head of the stairs on either side, so that, beneath these three arches, the whole space is open on the church entry floor the entire ^vidth of the vestibule, which gives to the whole a spacious and airy appearance. From this floor, stairs on either end lead to the singing gallery. Beneath this entry, on the vestry floor, is one of the same width, and from it is a door 4 feet wide, leading to the outside of the building ; one leading to a room 12 feet square, for wood and coal, beneath the church stairs ; also two others leading to the vestry, the dimensions of which are 42 by 49 feet, and 1 1 feet high in the clear ; connected with which arc two ante-rooms, each 20 feet 6 inches by 22 feet. Attached to each of these rooms is a closet, 4 feet wide and U feet long. The ante-rooms are separated from the vestry by largo doors, which move on castors, so that the whole may be thrown into one large room. The floor of the church contains 82 pews, 2 feet 10 inches wide, and 9 feet 7 inches in length, which provides 19 inches to a person, allowing G persons to a pew, making the house capable of seating in all, including the gallery, 650 persons. Tlie side aisles are 3 feet wide ; the one in the centre, 44 feet. The pulpit is of an original design, and is in strict accord- ance with the architectural character of the edifice. It is an im- itation of rosewood, and the seven circular-headed panels on the front are lined with garnet plush. The sofa connected with the pulpit is of rosewood, and was designed for the place it occupies ; the trimmings of the sofa, pulpit, and chairs are also of garnet plush. There is a choir gallery at the end of the church, over the entrance, connected with which is a room for the choir's rehear- sals, 24 by 12 feet, and 12 feet high. There ia a dado in each of the side aisles of the main floor, to the height of the window sUls, which is returned at the sides of each window, making a pedestal of sufficient width to include the window and the fresco pilasters at its sides. This dado has a capping and base, which, together with the doors of the church, are grained black walnut. The windows of the whole building, above the basement, are furnished with blinds on the inside, and are painted Paris green. The walls of the principal room arc 24 feet high, and these, with the whole interior of the church, are finely painted in distemper fresco, in the following manner : The side walls have a fine fluted Corin- thian pilaster on each side of all the windows, which support an entablature 3 feet deep, extending entirely around the church walls ; between each of these is a sunken panel, and inside of these is one which is raised ; over the windows is a rich moulding ornamented with a console, and ending at the pilasters with an acanthus lea£ On the back end, on either side of the recess, back of the pul- pit, is painted a niche standing on a pedestal, and finished like the windows. In the recess back of the pulpit is represented an arched panelled recess or passage, leading to a rotunda, in the centre of which stands a large cross ; the celling is very finely decorated by large panels, and at the angles are ornaments of Roman foliage, extending some 11 feet either way. In the centre of the ceiling is a cast-iron register, 3 feet in diameter, to admit the foul air to one of Emerson's ventilators, (which efi'ectually ventilates the room;) around this is a beautiful design of foliage, and on two of its sidei is seen a harp, supported by the leaves and scroUs. The tint of the ground is a gray lilac. The building was raised in November last, and has been entirely completed since that time. It has cost, including the land and furnishing, not far from $10,500. T. W. S. 136 GOTHIC ARCHITECTURE. GOTHIC ARCHITECTURE Gotliic, or what may be termed, with more pro- priety, English architecture, is that style which im- mediately succeeded the Norman, and the most prominent feature of which is the pointed arch, slender columns, and a predominancy of vertical lines. Wc should have been pleased to have given a full description of this kind of architecture ; but our limits not permitting, we shall content ourselves with simply giving a synopsis of some of its char- acteristics; and to those of our patrons who may wish for a more extensive knowledge of this branch of the science, we would refer them to a work known as the Glossary of Architecture, the fifth edition of which was published in London the past year. This work contains a very elaborate description of all that pertains to this branch of the science, and is a production of inestimable value. We have stated that this species of architecture immediately succeeded the Norman — indeed, it is a work of some nicety to draw the dividing line between them ; but, before proceeding further, we will remark that the Rev. Mr. Millers, of England, has divided the architecture on which we treat into three distinct classes, and his classification has met the approval of Rickman and Pugin, who are among the principal architectural \\Titers of England. The first style he terms the Early English, the second the Decorated, and the third the Perpendicular. We shall follow him in this respect, and shall describe each style re- spectively hereafter. The Early English, then, is the style which is nearest to the Norman, and it may be said to have grown out of it ; and here we beg leave to differ from the opinion that has at times found warm advocates, which is, that the form of the arch which characterizes this species of architecture was sug- gested by the intersection of branches of trees. This idea is, without doubt, the production of a fertile imagination, and, like the famous story of Callima- chus and the vase at Corinth, it may be regarded as a play of the fancy and a freak of ideality. One of the principal features of the Norman architecture is the very frequent use of the Roman arch ; and, by describing a second semicircle with a point in the circumference of one already drawn as a centre, we produce what is familiarly known as the Gothic arch, and a series of these we term intersected arches. This also is of firequent occurrence in the later Norman architecture ; and we deem it no departure from the principles of logic to deduce from this fact that the arch used in the English architecture was no invention, but simply a transfer to it from the Norman, and that, even with those with whom it originated, it was the result of accident rather than design. We thus give our reasons for the intrusion we make upon the favorite speculations of those who may differ from us, for we do so with all re- spect to their love of the ideal, and we would be the last to deprive them of the pleasure they may de- rive from the idea that those with whom one of the most beautiful of the productions of architecture had its origin were men endowed with great inventive talent, and that, too, which often manifested itself to an astonishing degree. But to proceed: we will again remark, that the first style is the Early English, and is, as its name suggests, the earliest of the three. The intersecting arches to which we have before referred characterized the Norman, as it was about to merge into it, and, in some instances, we find examples of the poiiited arch in the Norman, entirely by itself; thus the one has produced the other. The time when this style may be said to have had its rise was about the year 1200, and continued from this period to 1300, which extended through the reigns of John, Henry III., and Edward I. It is stated that, during the reign of Henry III. alone, no less a num- ber than one hundred and fifty-seven abbeys, priories, and other religious houses were founded in England ; and the erection of these was considered as among the most effectual means of obtaining the forgiveness of sins, and, consequently, the favor of Heaven. The principal characteristic of this style is, in the language of Gwilt, as follows : The arches are sharply lancet pointed, and lofty, in proportion to GOTHIC ARCHITECTURE. 137 their span. In the upper tiers, two or more are com- preliended under one, finished in trefoil or cinquefoil heads, instead of points, the separating columns being slender. Columns on whicii the arches rest are very slender in proportion to their iieight, and usually consist of a central shaft, surrounded by several smaller ones. The base takes the form of the cluster and the capital is frequently decorated with foliage, very elegantly composed. The tcin- doics are long, narrow, and lancet-shaped, whence some \\Titers have called this style the Lancet Gothic. They are divided by one plain mullion, or, in upper tiers, by two at most, finished at the top with some simple ornament, as a lozenge, or a trefoil. They have commonly small marble shafts on each side, both internally and externally ; two, three, or more, together, at the eas't or west end, and tier above tier. Roofs arc high pitched, and the ceilings vaulted, exhibiting the first examples of arches with cross springers only, which, in a short period, diverged into many more, rising from the capitals of the columns, and almost overspreading the whole sm-face of the vaulting. The longitudinal horizontal line which reigned along the apex of the vault was decorated with bosses of flowers, figures, and other fancies. Walls much reduced in thickness from those of the pre- ceding period ; they arc, however, externally strength- ened with buttresses, which, as it were, lean against them for the purpose of counteracting the thrust exerted by the stone vaults which form the ceil- ings, and which the walls and piers, by their own gravity, could not resist. The buttresses are, more- over, aided in their office by the pinnacles, adorned with crockets at their angles, and crowned with fiuial flowers, by which they are surmounted. The ornaments now become numerous, but they arc sim- ple and elegant. The mouldings are not so much varied as in the Norman style, and are generally, perhaps universally, formed of some combination of leaves and flowers, used not only in the cuxumference of arches, especially of windows, but the columns or pilasters are completely laid down with them — ti-e- foils, quatrefoils, cinqucfoils, roses, mullets, bosses, pa- terae, &c., in the spandrils, or above the keystones of the arches, and elsewhere. The ornamental pinna- cles on shrines, tombs, &c., are extremely high and acute, sometimes with, and sometunes without, niches under them. In east and west fronts, the niches are 18 filled with statues of the size of life, and larger, and are crowned with trefoil, &c., heads, or extremely acute pediments, formed by the meeting of two straight lines, instead of arcs. All these ornaments arc more sparingly introduced into large, entire edi- fices than in smaller buildings or added parts. The plans are, generally, similar to those of the preceding period; but that important feature, the tower, now begins to rise to a great height, and lanterns and lofty spires arc frequent accompaniments to the structure. It will natm'ally occur to the reader, that, in tiie transition from the Norman to this style, the archi- tects left one extreme for another, though it has been contended that the latter has its germ in the former. However that may be, the period of which we are now speaking was undoubtedly the parent of the succeeding styles, and that by no very forced or un- natural relationship. The principal examples of the early English style, in the catheckal churches of England, are to be seen at Oxford, in the chajiter-house ; Lincoln, in the nave and arches beyond the transept ; York, in the north and south transept ; at Durham, in the additional tran- sept ; Wells, the tower and the whole western front ; Carlisle, the choir ; Ely, the presbytery ; Worcester, the transept and choir ; Salisbitri/, the whole cathe- ch-al — the only unmixed example ; at Rochester, the choir and transept. " It is well worthy of observa- tion," says Ml-. Dallaway, " that though the gi-ound plans of sacred edifices are, generally spealdng, simi- lar and systematic, yet in no single instance which occurs to my memory do we find an exact and un- varied copy of any building which preceded it, in any part of the structure. A striking analogy of resem- blance may occur, but that rarely." The second class or style is the Decorated, and oc- cupied the period between 1300 and 1460. " Li the early part of the period," continues Gwilt, " the change, or rather progress, was extremely slow, and marked by little variation ; and indeed, until 1400, the style can scarcely be said to have been perfected ; but after that time, it rapidly attained all the improvement whereof it was susceptible, and so proceeded till about 1460, after which it assumed an exuberance of ornament, beyond which, as it was impossible to advance, it was in a predicament from which no change could be efiected but by its total abandon- ment. This style exhibits arches, less acute and more open, the forms varying." 138 GOTHIC ARCHITECTURE. Columns. — The central and detached shafts are now -worked together into one, from experience of the weakness of those of the previous style, exceedingly various in their combinations. The untulows are larger, divided by mullions into several lights, spreading and dividing at the top into leaves, flowers, fans, wheels, and fanciful forms of endless variety. These marks are constant, but in the proportionate breadth there is much variation ; for, after having expanded in the reigns of Edward I. and II., they grew narrower again in proportion to their height in that of Edward III., and also sharper. The head was then formed of lines just perceptibly curved, sometimes even by two straight lines, some- times just cur\-ed a little above the haunches, and then rectilinear to the apex. The eastern and western win- dows were very lofty and ample, and splendidly deco- rated with painted glass. In regard to the roof or ceiling, the vaulting is more decorated. The princi- pal ribs spread from their imposts, running over the vault lilie tracery, or, rather, with ti'ansoms divided into many angular compartments, and ornamented at the angles with heads, orbs, historical or legendary pictures, &c., elaborately colored and gilded. The ornaments are more various and labored, but not so elegant and graceful in character, as in the preceding style. Niches and tabernacles, with statues, are used in great abundance. Tiers of small ornamental arches are frequent. The pinnacles arc neither so lofty nor tapering, but are more riclily decorated with leaves, crockets, &c. Sculpture is introduced in much profusion, and is frequently painted and gilt; screens, stalls, doors, panelled ceilings, and other ornaments in carved and painted wood. Some of tlie principal examples of the ornamented English style in cathedral churches are, at Exeter, the nave and choir; Lichfield, uniformly; at Lincoln, the additions to the central tower; at Worcester, the nave ; York, nave, choir, and western front ; at Can- terbury, transept ; at Gloucester, transept and cloisters began ; Norwich, the spire and tower ; Salisbiiri/, spire and additions ; Bristol, the nave and choir ; Chichester, the spire and choir; Eli/, Our Lady's Chapel, and the central louvre ; Hereford, the chapter-house and cloisters, now destroyed. In the later part of the pe- riod, the choir at Gloucester, the nave at Canterbury, Bishop Beckington's additions at Wells, and from the upper transept to the great east window at Lincoln. FLORID ENGLISH, OR PERPENDICU- LAR STYLE. " There is," as Dr. Henry obser^'es, " a certain per- fection in art to which hmnan genius may aspire with success, but beyond which it is the apprehen- sion of many that improvement degenerates into false taste and fantastic refinement." " The rude sim- plicity of Saxon architecture was [ultimately] sup- planted by the magnificence of the ornamental Gothic; but magnificence itself is at last exhausted, and it terminated dm-ing the present period in a style cen- sm-able as too ornamental, departing from the gran- dem- peculiar to the Gothic, without acquiring pro- portional elegance; yet its intricate and redundant decorations arc well calculated to rivet the eye, and amaze, perhaps bewilder, the mind." The period of this style is from 1460 to the dissolution of the re- ligious houses in 1537, and comprehends, therefore, the reigns of Edward IV. and V., Richard III., Henry VII. and VIII. Its principal characteristics are arches, univer- sally flat, and wide in proportion to their height. The windows arc much more open than in the last period, flatter at the top, and divided in the upper part by transoms, which are almost con- stantly crowned with embattled work in miniature. The ceilings, or vaultings, spread out into such a variety of parts that the whole surface appears cov- ered with a web of delicate sculpture or embroidery thrown over it; and from different intersections of this ribbed work, clusters of pendent ornaments hang down, as Mr. Miller observes, like " stalactites in caverns." The flying buttresses are equally orna- mented, and the external sufaces of the walls are one mass of delicate sculpture. The ornaments, as may be deduced from the above particulars, are lavish and profuse in the highest degi-ee. Fretwork, figures of men and animals, niches and tabernacles, accompanied with canopies, pedestals, and traceries of the most exquisite workmanship, carried this style to the sum- mit of splendor ; and all these combined had, perhaps, no small share in producing the extinction it was doomed to undergo. Roslin and Holyrood Chapels, the first whereof was erected by Sir William St. Clair, for richness and variety of ornamental carvings camiot be exceeded. Its plan is without parallel in any other specimen of the fifteenth century. The latter was finished by GOTHIC AKCHITECTURE. 139 James, the second ol that name, in 1440, and is a beautiful example, with flying buttresses, which are more ornamented than any even in England. Ex- amples of tlie Florid Gothic or Perpendicidar style are to be seen at the cathedi-al churches of Glouces- ter, in the Chapel of Our Lady ; at Oxford, in the roof of the choir ; at Ely, in Alcock's Chapel ; at Peterboro% in Our Lady's Chapel ; and at Hereford, in the north porch. In conventual churches at Windsor, St. George's Chapel at Cambridge, King's College Chapel at Westminster, King Henry VII.'s Chapel; at Great 3Ielverit, in Worcestershire, the tower and choir; at Christ's Church, Oxford, the roof of the choir ; and at Evesham Abbe?/, in Worces- tershhe, the campanile and gateway. Among other principal examples in this style, it may be well to mention that Scotland boasts of many fine specimens of ecclesiastical architectiure. The Abbeys of Melrose and Kelso, founded by David I., as well as those in Dryburgh and Jedburgh, — all in Roxbm-ghshire, — prove that the art advanced to as great perfection north of the Tweed as it did in England. For parochial churches, except in some very few specimens in Somersetsliire, and there, perhaps, only in parts, we are unable to refer the reader to a com- plete specimen, in all its parts, of the perpendicular style. The pulpit and screen at Dartmouth, in Dev- onshire, are worthy of his notice. The following synoptical view of the general di- mensions of the above cathedrals, we think, may prove occasionally useful to the reader, by enabling him to compare the whole of them and their parts with each other. Dallaway, without the remotest idea of the principles in question, has observed, with his usual sagacity, that there appears in them " a distribution of parts wiiicli will hold ahnost gen- erally, that the width of the nave is that of both the aisles, measured in the place to the extremity of the buttresses externally ; and that the breadth and height of the whole building arc equal. In the more ancient churches, the aisles are usually of the width of the space between the dividing arches." Some idea of the principle is conveyed in the plates of jNIilan Cathedral, curiously introduced into the very early translation of Viti-uvius by Ca;sar Cesarianus, a work of great curiosity, and of which copies arc now rarely met with. A Synoptical Vieiv of the leading- Dimensions of the English Cathedrals. Total Cailiedral. internal Naves and Aisle J. Choirs. Transepts. Spires and Towers. Lengtli. Length. Breadth. Height. Length. Breadth. Height. Breadth. Height. Winchester, 545 247 86 78 138 73 186 Ely, . 517 327 73 70 101 73 70 178 Tower, . 210 Canterbury, 514 214 70 80 150 74 80 154 Do., . . 235 Old St. Paul's, . 500 a35 91 103 165 43 88 248 Spire, . 534 York, . 498 264 109 99 131 99 222 Tower . 234 Lincoln, 498 83 83 — 227 Do., . . 260 Westminster, 489 130 96 101 152 151 189 Peterboro', . 480 231 78 78 138 78 203 Louvre, . 150 Salisbury, . 452 246 76 84 140 — 84 210 Spire, . 387 Durham, . 420 — — 117 33 71 176 Tower, . 214 Gloucester, 420 174 84 67 140 86 144 Do., . . 225 Lichfield, . 411 213 67 — 110 67 Spire, 258 W. 183 Norwich, . 411 230 71 — 165 — — 191 Do., . . 317 Worcester, 410 212 78 — 126 74 130 Tower, . 196 Chichester, 401 205 91 61 100 — 131 Spire, . 267 Exeter, 390 173 74 69 131 69 140 Tower, . 130 Wells, 371 191 67 67 106 — 67 135 Do., . . 160 Hereford, anct. . 370 144 68 68 105 — 64 140 Chester, . 348 73 73 Tower, . 127 Rochester, . 306 150 65 — 156 — 123 Spire, . 156 Carlisle, . 213 71 71 137 71 Bath, . 210 136 72 78 — 126 Tower, . 162 Bristol, 175 100 75 73 100 «__ 128 Do., . . 127 Oxford, . 154 74 54 41 80 — 374 102 Spire,. . 184 140 GOTHIC ARCHITECTURE. To the above vvc subjoin the correspondent dimen- sions of the several component parts of some of tlic cathedral churches enumerated, which we consider useful to the student as well as the general reader. Total Length. Feet. Chichester cathedral church, , 410 Norwich cathedral church. . . 411 Worcester cathedral church, . 410 Durham cathedral church. , . 420 Gloucester conventual church, • 420 Ucighls of Naves. Style. Feet Salisbury cathedral church, . 84 Pointed arch. Lincoln cathedral church, . . 83 Pointed arch. Canterbury cathedral churcli. . 80 Pure Gothic. Peterboro' conventual church, . 78 Norman. Winchester cathedi-al chm-ch, . 78 Pure Gothic. Durham cathedral church, . . 71 Norman. Ely cathedral chm'ch. . 70 Norman. Exeter cathedral church, . . 69 Pointed arch. Gloucester conventual church, . G7 Norman. Wells cathedral church. . 67 Pointed arch. Breadths of Naves and Aisles. Feet Feet. Feet. Noi-wlch, . 71 Exeter, . . 74 Durham, . 80 Bristol, . . 73 Salisbmy, . 76 Lincoln, . 83 Chester, . . 73 Peterboro', . 78 Gloucester, 84 Ely, ... 73 Worcester, . 78 Winchester, 85 Canterbury, 74 The author just quoted, in reference to the tables here given, says of them, that "the parallel will afford VTs, at one view, authentic information con- cerning the proportion of one constituent part to another of every cathedral in England which is wor- thy the notice of an architect. Such," he continues, " a coincidence of dimensions as that which is found in many of tlicm can scarcely be supposed to be the effect of chance, especially where the buildings are contemporary, and of an exactly correspondent style." It appears that the equality of proportions is con- fined to each era and style of ecclesiastical architect- ure in so remarkable a degree as to lead us to con- jecture that they might have been designed by the same architect. " The constant rivalry," says Dalla- way, "which subsisted between the magnificent prel- ates, was excited upon the erection of any part of a cathedral of superior beauty, and imitated in those of the same kind which were then undertaken ; and the architect who had once displayed great talents was invited to repeat the more perfect performance upon which he had rested his professional fame." We have not considered it necessary to devote a special portion of our work to the conventual archi- tecture of England, because it followed the style of the time. It was of great splendor. The ground plans of their habitable portions were usually, though not always, quackangular, and in the later ages par- took of the improvements in domestic architecture, as in the colleges built by Wykham and Waynflete, and many of the episcopal residences. Glastonbury and Reading presented exceedingly fine examples of it ; the former comprised within its walls sixty acres of gi'ound. We have thus given, although very briefly, an ac- count of the rise and progi'css of a species of archi- tecture which is in itself a wonder, and which has set up an eternal defiance to him who would speak light- ly of the deep conception it develops, or the wonder- ful fertility of the inventive genius it demonstrates. It was the production of a peculiar age, and, true to its time, it mirrors in every case a transcript of the mind of him who conceived it. The low roof of the Indian Temple of Elephanta, or the Egyptian Phila; or Edfu, were lofty enough for their deities. The Parthenon and the Erectheum of classic Greece were sufficiently spacious and significant of the gods they worshipped ; but to the mind of the Christian, whose vision extended beyond the confines of temples that were made with hands, the most gorgeous temple of Grecian story, although composed of the purest mar- ble and of the most classic design, was but mean and grovelling. Their religion was of a. loftier nature, and their aspirations could only be satisfied when, with awful sublimity, they saw the spire of Salisbury towering in majestic significance for four hundred feet in the air. In that huge pile, awful yet majestic, they recognized a divinity, the colossal grandeur of which awakened and perpetuated in their bosoma emotions of adoration and praise. Beneath the sky of ancient Rome stands one of the seven wonders of the world ; and, beneath that of London, the glory of Roman architecture on the soil of Old England. But in constructing the Cathedral Churches of St. Peter's and St. Paul's, the conception of Raphael, and An- I'l.'i. Kl.v.ili,.ii iin.l S.-,li..ii ..r llir ( 111. I M'm.li." Ill 111.- . Mir-.iii. .■ -^-ili-vi-av. i'i.;i;i . yi ^ii aavW'.aji/ii. STTOIKlfu I'l.Klil I'l.ll' GOTHIC ARCHITECTURE, 141 gelo, and Wren were trammelled by the rules and proportions of an order, and a Roman sternness characterizes each pile. Li these is seen, it is true, the great victory that science and skill have won over disorder and ignorance, but in Gloucester and Win- chester the very essence of art and ideality. The perfect columniations and nicely-arranged entabla- tures of the former speak to us, it is true, with a bold- ness that well becomes the Roman ; but the flowing tracery and lofty arches of the latter breathe an air of poctiy : while the gTcat domes of the one fill the mind with majesty and awe, the towering spires of the others address their solemn eloquence to the soul. We would not underrate the talent which produced the great realities we place in contrast ; we give them the glory which a matured science and a ripe skill have hung around them ; but we claim for the others that each conception is distinctly identified with the time which gave it bu-th, and that they were the out- gushings of souls who were striving to gain the mas- tery over darkness and degradation, and whose lof- tiest aspkations were the establishment and perpetuity of a reformed religion ; that they are the mementoes of a genius and invention which were lent to a peo- ple who had been appointed to assist at an important era in a reform which is to ultimately rid the race of their vices and transgressions. It is to be acknowl- edged that the means made use of by the clergy were often censurable, and at variance with Lhe principles of the religion they would inculcate ; but, notwith- standing all this, behind the definite and sharp scientific outlines with which the reason and expe- rience of six centuries have bouirded the dominion of religious duty, we see standing out fi-om it all a detertnination and an accomplishment ; an intense desire, amounting in itself to a demand, for a deeper reverence for the principles of religion, as they under- stood tlicm,and now, after sLx centuries have elapsed, the crowded aisles of a hundred cathedrals speak out their triumph and success, and the walls which en- close them are but votive monuments of the immen- sity of their wonderful genius. — Editors. Plates 9§, 99, 100, 101. On these plates we have given examples of Gothic architecture, with their details. These plates are transcripts of the examples they arc designed to rep- resent, and are taken fi-om Pugin's Gothic Architect- ure, with the figures and scale annexed. They are not inserted as illustrations of cither of the styles we have described, neither do we give them as elements of those styles, for did we attempt to illustrate each style in a manner that would do justice to the stu- dent, some twelve plates, at least, would be required to give him even a limited knowledge of the arches, doors, windows, and columns belonging to each style ; and to continue the illustration by examples of roofs, ceilings, mouldings, &c., &c., all of which would be demanded, twice that number would be reqiiired in addition ; and as it was not the original design of the work to treat upon this part of the science, we have contented ourselves with giving our patrons a descrip- tion of the principal elements which compose it, and would refer them, in addition to the works we have named, to Rickman's Gothic Ai'chitecture, and also to the publications of Britton and Pugin. The four plates alluded to contain so great a va- riety of useful and practical information for the coun- try artisan, or to those who do not have access to the works to which we refer them, (and for those our whole work is principally designed,) that we have been induced to place them in our edition. — Editors. 142 BUILDING. BUILDING. Aldrich tcUs us that, in choosing a situation for building, its vicin- ity to public edifices should be principally attended to j that is, we should build as near as convenient to the place Tvliere the business of the o-micr chiefly calls him. " Every one would -ivish to be near a church," (or, perhaps, should wish to be so,) " but especially a priest ; the la-\\-yer near the hall of justice ; the merchant near the exchange ; the trader in the principal street ; and every other citi- zen, in the same manner, •n-ould choose his dwelling according to his occupation — not far from the river, if any flow near the city ; at a distance from a tallow chandler, a brewer, a soap boiler, or any other business attended with an unsavory smell ; far from the noise of the anvil, the hammer, and the saw ; and, above aU, (as Cato says,) at a distance from bad neighbors. In short, that spot is most eligible in which you can construct a regular house ; that is, one with right angles — where room, leisure, and cleanliness may be obtained, and you may procure to your house the advantages of a rural situation. If all the above conveniences cannot be met >vith, (and it is very seldom, if desired, that they can be,) it is prudent to aim at such as may be desirable and are attainable. Under this general term, which implies the con- struction of an edifice, according to the rules laid down by the different artificers employed, we purpose to treat of the respective business of the mason, brick- layer, plasterer, slater, plumber, painter, and glazier ; previous to which it will be necessary to consider the sinking of the foundation, the due mixture of the in- gredients which compose the mortar, and the art of making bricks, upon the whole of which materially depends the stability of an edifice. As firmness of foundation is indispensable, wher- ever it is intended to erect a building, the earth must be pierced by an non bar, or stuck with a rammer, and, if found to shake, must be bored with a well- sinker's implement, in order to ascertain whether the shake be local or general. If the soil is in general good, the loose and soft parts, if not very deep, must be excavated until the laborers arrive at a solid bed capable of sustaining the pier or piers to be built. If not very loose, it may be made good by ramming into it very large stones, packed close together, and of a breadth proportionate to the intended weight of the building ; but where very bad, it must be piled and planked. In places where the soil is loose to any great depth, and over which it is intended to place apertures, such as doors, windows, &c., while the parts on which the piers are to stand are firm, the best plan is to turn an inverted arch under each intended aperture, as then the piers, in sinking, will carry with them the inverted arch, and, by compressing the gi'ound, compel it to act against the under sides of the arch, which, if closely jointed, so far from yielding, will, with the abutting piers, operate as one solid body ; but, on the contrary, if this expedient of the inverted arch is not adopted, the part of the wall under the aperture, being of less height, and, consequently, of less weight than the piers, will give way to the resistance of the soil acting on its base, and not only injure the brick work between the apertures, but fracture the window heads and sills. In constructing so essential a part as the arch, great attention must be paid to its curvature, and we strongly recommend the parabolic curve to be adopted, as the most effectual for the purpose ; but if, in consequence of its depth, this cannot conven- iently be introduced, the arch should never be made less than a semicircle. The bed of the piers should be as uniform as possible ; for though the bottom of the trench be very firm, it will, in some degree, yield to the great weight that is upon it, and if the soil be softer in one part than in another, that part which is the softest wUl, of course, yield more to the pressure, and cause a fracture. K the solid parts of the trench happen to be under the intended apertures, and the softer parts where piers are wanted, the reverse of the above practice must be resorted to ; that is, the piers must be buUt on the firm jjarts, and have an arch that is not in- verted between them. In performing this, attention must be paid to ascertain whether the pier will cover the arch ; for if the middle of the pier rest over the middle of the summit of the arch, the narrower the pier is the gi-eater should be the ciu'vature of the arch at its apex. When suspended arches are used, the intrados ought to be kept clear of the ground, that the arch may have its due effect. When the gi'ound is in such a state as to require the foundation merely to be rammed, the stones are hammer dressed, so as to be of as little taper as possi- ble, then laid of a breadth proportioned to the weight BUILDING. 143 that is to be rested upon them, and afterwards well rammed together. In general, the lower bed of stones may be allowed to project about a foot from the face of the wall on each side, and on this bed another com-se may be laid, to bring the bed of stones on a level with the top of the trench. The breadth of this upper bed of stones should be four inches less than the lower one ; that is, projecting about eight inches on either side of the wall. In all kinds of walling, each joint of every coiu'se must fall as nearly as possible in the centre, between two joints of the course immediately below it ; for, in all the various methods of laying stones or bricks, the principal aim is to procure the greatest lap on each other. MORTAR. Li making mortar, particular attention must be paid to the quality of the sand, and if it contain any proportion of clay or mud, or is brought fi.-om the sea-shore, and contains saline particles, it must be washed in a stream of clear water till it be di- vested of its impiuities. The necessity of the fii-st has been clearly proved by Mr. Smeaton, who, in the course of a long and meritorious attention to his profession as an engineer, has found that when mor- tar, though otherwise of the best quality, is mixed with a small proportion of unburnt clay, it never acquhes that hardness which, without it, it would have attained ; and, with respect to the second, it is evident that, so long as the sand contains any saline particles, it cannot become hard and diy. The sharper and coarser the sand is, the better for the mortar, and the less the quantity of lime to be used ; and sand being the cheapest of the ingredients which compose the mortar, it is more profitable to the maker. The exact proportions of lime and sand are still undetermined ; but in general, no more lime is required than is just sufficient to surround the parti- cles of the sand, or sufficient to preserve the neces- sary degree of plasticity. Mortar, in which sand forms the gi-eater portion, requires less water in its preparation, and, conse- quently, is sooner set. It is also harder and less lia- ble to shrink in drying, because the lime, while dry- ing, has a greater tendency to shrink than sand, which retains its original magnitude. The general proportions given by the London buUdcrs is 1^ cwt., or 37 bushels of lime, to 2^ loads of sand ; but, if proper measures be taken to procure the best burnt lime and the best sand, and in tempering the mate- rials, a greater portion of sand may be used. There is scarcely any mortar that has the lime well cal- cined, and the composition well beaten, but that will be found to require two parts of sand to one part of unslaked lime ; and it is worthy of observation, that the more the mortar is beaten, the less proportion of lime suffices. Many experiments have been made, with a view to obtain the most useful proportion of the ingre- dients, and, among the rest. Dr. Higgins has given the following : " Lime, newly slaked, one part ; fine sand, three parts ; and coarse sand, four parts." He also found that one fourth of the lime of bone ashes greatly improved the mortar, by giving it tenacity and rendering it less liable to crack in the drying. It is best to slake the lime in small quantities as required for use, about a bushel at a time, in order to secm-e to the mortar such of its qualities as would evaporate were it allowed to remain slaked for a length of time. But if the mortar be slaked for any considerable time previous to being used, it should be kept covered up, and, when wanted, should be rebcaten. If care be taken to secure it from the action of the atmosphere, it may thus remain covered up for a considerable period, without its strength be- ing in the least affected ; and, indeed, some advan- tages are gained, for it sets sooner, is less liable to crack in the drying, and is harder when dry. Grout, wloich is a cement containing a larger pro- portion of water than the common mortar, is used to run into the narrow interstices and irregular courses of rubble-stonc walls ; and as it is reqviired to con- crete in the course of a day, it is composed of mor- tar that has been a long time made and thoroughly beaten. Mortar, composed of pm-e lime, sand and water, may be employed in the linings of reservoirs and aqueducts, provided a sufficient time is allowed for it to dry before the water is let in ; but if a sufficient time is not allowed, and the water is admitted while the mortar is wet, it will soon fall to pieces. There are, however, certain ingredients which may be put into the common mortar to make it set immediately under the water ; or, if the quicklime composing the 144 BUILDING, mortar contains in itself a certain portion of burnt clay, it wUl possess this property. For further in- formation on this head, the reader is referred to the sub-head — Plasterinff. MASONRY. Masonry is the art of cutting stones, and building them into a mass, so as to form the regular sur- faces which arc requu-ed in the construction of an edifice. The chief business of the mason is to prepare the stones, make the mortar, raise the wall with neces- sary breaks, projections, arches, apertures, &c., as in- dicated by the design. A wall built of unhewn stone, whether it be built with mortar or otherwise, is called a rubble jvall. Rubble worlv is of two kinds, coursed and uncoursed. In coursed rubble, the stones are gauged and di-cssed by the hammer, and thrown into different heaps, each heap containing stones of equal thickness; and the masonry, which may be of different thicknesses, is laid in horizontal com'ses. In uncom-sed rubble, the stones are placed promiscuously in the wall, with- out any attention being paid to arrange them in courses ; and the only preparation the stones under- go is that of knocking off the sharp angles with the thick end of a tool called a scabling hammer. Walls are often built with an ashlar facing of fine stone, averaging about fom- or five inches m thickness, and backed with rubble work or brick. Walls backed with brick or uncoursed rubble are liable to become convex on the outside, from the great number of joints, and the difficulty of placing the mortar, which shrinks in proportion to the quan- tity, in equal portions, in each joint ; consequently, walls of this description are much inferior to those where the facing and backing are built of the same material, and with equal care, even though both of the sides be uncoursed. When the outside of a wall is faced with ashlar, and the inside is coursed rubble, the courses of the backing should be as high as pos- sible, and set within beds of mortar. Coursed rub- ble and brick backings are favorable for the insertion of bond timber ; but in good masonry, wooden bonds should never be in continued lengths, as, in case of cither fire or rot, the wood will perish, and the masonry will, by being reduced, be liable to bend at the place where the bond was inserted. When timber is to be inserted into walls for the purposes of fastening buttons for plastering or skirt- ing, (kc, the pieces of timber ought to be so disposed that the ends of the pieces be in a line with the wall. In a wall faced with ashlar, the stones are gen- erally about 2 feet or 2i feet in length, 12 inches in height, and 8 inches in thickness. It is a very good plan to incline the back of each stone, to make all the backs thus inclined run in the same direction, which gives a small degree of lap in the setting of the next course ; whereas, if the backs arc parallel to the front, there can be no lap where the stones run of an equal depth in the thickness of the waU. It is also advantageous to the stability of the wall to se- lect the stones, so that a thicker and a thinner one may succeed each other alternately. In each course of ashlar facing, cither with rubble masonry or brick backing, thorough stones should occasionally be in- troduced, and their number be in proportion to the length of the course. In every succeeding course, the thorough stones should be placed in the middle of every two thorough stones in the course below; and this disposition of bonds should be punctually attended to in all cases where the courses are of any great length. Some masons, in order to prove that they have introduced sufficient bonds into their work, choose thorovigh stones of a greater length than the thickness of the wall, and afterwards cut off the ends ; but this is far from an eligible plan, as the wall is not only subject to be shaken, but the stone is itself apt to split. In every pier, between windows and other apertures, every alternate jamb stone ought to go through the wall with its bed perfectly level. When the jamb stones are of one entire height, as is fre- quently the case when architraves are ^\Tougllt upon them, upon the lintel crowning them, and upon the stones at the ends of the courses of the pier which are adjacent to the architrave jamb, every alternate stone ought to be a thorough stone : and if the piers between the apertures be very narrow, no other bond stone is required ; but where the piers arc wide, the number of bond stones are proportioned to the space. Bond stones must be particularly attended to in all long courses below and above windows. Iron clamps are now used in all cases where it is practicable, instead of thorough stones. The shrink- ing of the mortar in the backing is very apt to start BUILDING. 145 the thorough stone from its true position, which either fractures it, or causes the wall to bulge, and open the seams on the outside. This inconvenience is obvi- ated by the use of clamps. All vertical joints, after receding about an inch with a close joint, should widen gradually to the back, thereby forming hollow spaces of a wedge-like figure for the reception of mortar, rubble, &c. The adjoinmg stones should have their beds and vertical joints filled from the face about three quarters of an inch inwards, with oil putty, and the rest of the beds must be fiUed with well-tempered mortar. Putty cement will stand longer than most stones, and will even remain permanent when the stone itself is mu- tilated. All walls cemented with oU putty, at first look unsightly ; but this disagreeable effect ceases in a year or less, when, if care has been taken to make the color of the putty suitable to that of the stone, the joints will hardly be perceptible. In selecting ashlar, the mason should take care that each stone invariably lays on its natural bed, as, from carelessness in this particular, the stones frequently flush at the joints, and sooner admit the corrosive power of the atmosphere to take effect. It ought also to be observed, that, in building walls or insulated piUars of small horizontal dimensions, every stone should have its bed perfectly level, and be without any concavity in the middle ; because, if the beds are concave, the joints wUl most probably flush when the piUars begin to sustain the weight of the building. Care should also be taken that every course of masonry in such piers be of one stone. Having thus given to the practical mason an out- line of the subject of walling, we will proceed to the consideration of the more difficult branches of the art — that of constructing arches and vaults. DEFINITIONS. An arch, in masonry, is that part of a building which is suspended over a given plane, supported only at its extremities, and concave towards tlie plane. The upper surface of an arch is called the extrados ; and the under surface, or that which is opposite the plane, the intrados. The supports of an arch are called the spring ivalls. The spring-ing lines are those common to the sup- ports and the intrados, or the line which forms the intersection of the arch with the surface of the wall which supports it. 19 The chord or span is a line extending from one springing line to the opposite one. Section of the hollow of the arch is a vertical plane, supposed to be contained by the span and the in- trados. The height or rise of the arch is a line drawn at right angles from the middle of the chord, or span- ning line, to the intrados. The croivn of the arch is that part which the ex- tremity of the perpendicular touches. The haunches or flanks of the arch are those parts of the curve between the crown and the springing line. When the base of the section, or spanning line, is parallel to the horizon, the section will consist of two equal and similar parts, so that, when one is applied to the other, they will be found to coincide. Arches are variously named, according to the fig- ure of the section of a solid that would fill the void, as circular, elliptical, cycloidal, catenarian, parabolical, &c. There are also pointed, composite, and lancet or Gothic arches. A rampant arch is when the springing lines are of two unequal heights. When the intrados and extrados of an arch are parallel, it is said to be extradossed. There are, however, other terms much used by ma- sons : for example, the semicircular are called perfect arches; and those less than a semicircle, imperfect, surbused, or diminished arches. Arches are called stilted when they are higher than a semicircle. A vault is an arch used in the interior of a build- ing, overtopping an area of a given bomidary, as a passage, or an apartment, and supported by one or more walls, or pillars, placed without the boundary of that area. Hence an arch in a wall is seldom or never called a vault ; and every vault may be called an arch, but every arch cannot be termed a vault. A groin vault is a complex vault, formed by the intersection of two solids, whose surfaces coincide with the intrados of the arches, and are not confined to the same heights. An arch is said to stand upon splayed jambs when the springing lines are not at right angles to the face of the wall. In the art of constructing arches and vaults, it is necessary to bmld them in a mould, until the whole is closed ; the mould used for this purpose is called a centre. 146 BUILDING. The intrados of a simple vault is generally formed of a portion of a cylinder, cylindroid, sphere, or sphe- roid ; that is, never greater than the half of the solid ; and the springing lines which terminate the walls, or when the vault begins to rise, are generally straight lines, parallel to the axis of the cylinder or cylindroid. A circular wall is generally terminated with a spherical vault, which is either hemispherical, or a portion of a sphere less than a hemisphere. Every vault which has a horizontal, straight axis is called a straight vault; and, in addition to what we have ab-eady said, the concavities which two sol- ids form at an angle receive likewise the name of arch. An arch, when a cylinder pierces another of a greater diameter, is called cylindro-cylindric. The term cylindro is applied to the cylinder of the greatest diameter, and the term cylindric to the less. If a cylinder intersect a sphere of greater diameter than the cylinder, the arch is called a sphero-cylindric arch; but, on the other hand, if a sphere pierce a cylinder of greater diameter than the sphere, the arch is called a cylindro-spheric arch. If a cylinder pierce a cone, so as to make a com- plete perforation through the cone, two complete arches will be formed, called cono-cylindric arches; but, on the contrary, if a cone pierce a cylinder so that the concavity made by the cone is a conic sur- face, the arch is called a cylindro-conic arch. If , in a straight wall, there be a cylindric aperture continuing quite through it, two arches will be formed, called plano-cylindric arches. Every description of arch is, in a similar manner to the above, denoted by the two preceding words — the former ending in o, signifying the principal vault, or surface cut through ; and the latter in ic, signify- ing the description of the aperture which pierces or intersects the wall or vault. When groins are introduced merely for use, they may be built either of brick or stone ; but, when in- troduced by way of proportion or decoration, their beauty will depend on the generating figures of the sides, the regularity of the surface, and the acuteness of the angles, which should not be obtruded. In the best buildings, when durability and elegance are equally required, they may be constructed of wrought stone ; and, when elegance is wanted, at a trifling expense, of plaster, supported by timber ribs. In stonecutting, a narrow surface formed by a point or chisel on the surface of a stone, so a# to coincide with a straight edge, is called a draught. FORMATION OF STONE ABCHES. The formation of stone arches has always been considered a most useful and important acquisition to the operative mason ; in order, therefore, to remove any difficulties which might arise in the construction of arches of different descriptions, both in straight and circular walls, we shall here introduce a few ex- amples, which, it is hoped, with careful examination, will greatly facilitate a knowledge of some of the most abstruse parts of the art. Plate 102. To find the moulds necessary for the construc- tion of a semicircular arch, cutting a straight wall obliquely. Fig. 1, No. 1. Let A B C D E F G H be the plan of the arch ; I K L M the outer line ; and N O P Q the inner line on the elevation. a b c d e, on the elevation, shows the bevel of each joint or bed from the face of the wall ; and a b c d e, below, gives the mould for the same, where x y on the elevation corresponds with xy 2it a. The arch mould, No. 2, is applied on the face of the stone, and, on being applied to the parts of the plan, gives, of course, the bevel of each concave side of the stone with the face — that is, K to O, on the elevation. To find the mould for constructmg a semicir- cular arch in a circular wall. Fig. 2, No. 1, is the elevation of the arch, and No. 2 the plan of the bottom bed from q to r. a to b is what the arch gains on the circle from the bottom bed k o to I ; and c to d is the projection of the intrados to p, on the point /, p. Nos. 2, 3, and 4 are plans of the three arch stones, 1, 2, 3, in the elevation ; and Nos. 5 and 6 are moulds to be applied to the beds of stones 1 and 2, in which s c equals 5 c in No. 2, and t to equals t to in No. 3. In No. 1, k Ip is the arch or face mould. When the reader is thoroughly proficient in the construction of arches under given data, as the cir- cumstances of the case may point out, he may pro- ceed to investigate the principles of spherical domes and groins. A(a®rai£3. I'l.KU « I I BUILDING. 147 Figs. 3 and 4 show the principles of developing the sofRts of the arches in the two preceding exam- ples. In each the letters of reference are alike, and the operation is precisely the same. Let A B D E be the plan of the opening in the wall, and A F B the elevation of the arch ; produce the chord A B to C, divide the semicurcle A F B into any number of parts, the more the better, and with the compasses set to any one of these divisions, run it as many times along A C as the semicircle is divided into ; then draw lines, perpendicular to B C, through every division in the semicircle and the line C A, and set the distance 1 b, 2 d, 3 f, &c., respec- tively equal to ab c d ef, &c., and then, by tracing a curve through these points and finding the points in the line G D, in the same manner, the soffit of the arch is complete. Fig. 5 shows the method of constructing spherical domes. No. 1 mould is applied on the spherical surface to the vertical joints, and No. 2 mould on the same surface to the other joints, and, in both cases, the mould tends to the centre of the dome. 3, 4, 5, 6, 7, and 8 are moulds which apply on the convex surface to the horizontal joint, the lines a b, c d, e f, &c., being at right angles to the different radii, b c, d c,f c, &c., and produced until they inter- sect the perpendicular a c ; the different intersections are the centres which give the circular leg of the mould, and the straiglit part gives the horizontal joint. Fig. 6 exhibits the plan of a groined vault. Lay down the arch, either at the full or half size, on a floor or piece of floorcloth, then divide and draw on the plan the number of joints in the semicircular arch, and from the intersections with the diagonals draw the transverse joints on the plan, and produce them tUl they touch the intrados of the elliptical arch, the curve of which may be found by setting the cor- responding distances from the luie of the base to the curve ; thus a b equal to a b. This being accom- plished, di-aw the joints of the elliptical arch in the manner of which we give c rf as a specimen. To draw the joint c d, draw chord e c and bisect it, draw a line from the centre c through the bisecting point, and produce it tUl it touches the perpendicular ef; and c d, being at right angles to c /, will be the joint required. In the same manner the others are found. By examination, it will be seen that a rectangle circumscribing the mould 3, 3, gives the size of the stone in its square state, and that, if each stone in both arches be thus enclosed, the dimensions for each will be found, as also the position in which the moulds must be placed. The dark lines give the different bevels, which must be carefully prepared and applied to the stones in the manner represented in the figure. To draw the joints of the stones for an elliptical arch in a wall, &c. Fig. 7. The curve is here described by the inter- section of lines, which certainly gives the most easy and pleasing curve, as segments of circles apply only under certain data, or in the proportion which the axis major has to the axis minor, while the intersec- tion of lines apply to any description of ellipses. Find the foci F. In an ellipsis, the distance of either focus from one extremity of the axis minor is equal to the semi-axis major ; that is, D F is equal to c C. Then, to find any joint, a b, draw lines from both foci through the point b, as F e, / d, and bisect the angle d b ehy the line a b, which is the joint required. BRICKLAYING. In building upon an inclined plane, or rising ground, the foundation must be made to rise in a series of level steps, according to the general rise of the ground, to insure a firm bed for the courses, and prevent them from sliding ; for if this mode were not adopted, the moisture in the foundations, in wet weather, will in- duce the inclined parts to descend, to the manifest danger of fracturing the walls and destroying the building. Li walling, in dry weather, when the work is re- quired to be firm, the best mortar must be used, and the bricks must be wetted or dipped in water as they are laid, to cause them to adhere to the mortar, which they would not do if laid dry ; for the dry, sandy na- ture of the brick absorbs the moisture of the mortar, and prevents adhesion. In carrying up the wall, not more than four or five feet of any part should be built at a time ; for, as all walls shrink immediately after building, the part which is first carried up will settle before the adja- cent part is carried up to it, and, consequently, the 148 BUILDING. shrinldng of the latter will cause the two parts to separate ; therefore, no part of a wall should be car- ried higher than one scaffold, without having its contingent parts added to it. In carrying up any particular part, the ends should be regularly sloped off, to receive the bond of the adjoining parts on the right and left. There are two kinds of bond in brick work, which differ materially from each other. Bricks laid length- wise in the direction of the wall are called stretchers, and those laid in an opposite way, crossing the direc- tion of the wall, are called headers. The old English bond is a continuation of one Idnd throughout in the same course or horizontal layer, and consists of alter- nate layers of headers and stretchers — the headers serving to bind the wall together in a longitudinal direction, or lengthwise, the stretchers to prevent the wall splitting crosswise, or in a transverse direc- tion. Of these two evils, the former is by much the worst kind, and is, therefore, the most dreaded by the bricklayer. The brick work of the Romans was of this kind of bond. The other description of bond, called Flemish bond, consists in placing a header and a stretcher alternately in the same course. The latter is deemed the neat- est and most elegant ; but, in the execution, is at- tended with great inconvenience, and, in most cases, does not unite the parts of a wall with the same de- gree of firmness as the English bond. In general, it may be observed, that whatever advantages are gained by the English bond in tying a wall together in its thickness, are lost in the longitudinal bond, and vice versa. To remove this inconvenience in thick walls, some builders place the bricks in a cone at an angle of forty-five degrees, parallel to each other, through- out the length of every course, but reversed in the alternate courses ; so that the bricks cross each other at right angles. But even here, though the bricks in the cone have sufficient bond, the sides are very imperfectly tied, on account of the triangular in- terstices formed by the oblique direction of the in- ternal bricks against the fiat edges of those in the outside. Concerning the English bond, it may be observed, that, as the longitudinal extent of a brick is nine inches and its breadth four and a half, to prevent two vertical joints from running over each other at the end of the stretcher from the corner, it is usual, after placing the retiu-n corner stretcher, which occupies half the length of this stretcher, and becomes a header in the face, as the stretcher is below, to place a quar- ter brick on the side, so that the two together extend six inches and three quarters, being a lap of two inches and a half for the next header. The bat in- troduced is called a closer. A similar effect may be obtained by introducing a three-quarter bat at the corner of the stretching course, so that the corner header being laid over it, a lap of two inches and a quarter will be left at the end of the stretch- ers below, for the next header, which, being laid on the joint below the sti-etchers, will coincide with its middle. In the winter, it is very essential to keep the un- finished wall from the alternate effects of rain and frost ; for, if it is exposed, the rain will penetrate into the bricks and mortar, and, by being converted into ice, expand, and burst or crumble the materials in which it is contained. The decay of buildings, so commonly attributed to the effect of time, is, in fact, attributable to this source ; but as finished edifices have only a vertical surface, the action and counteraction of the rain and frost extend not so rapidly as in an unfinished wall, where the horizontal surface permits the rain and frost to have easy access into the body of the work. Great care, therefore, must be taken, as soon as the frost or stormy weather sets in, to cover the unfinished walls either with straw, which is the most common, or weather boarding. When weather boarding is employed, it is advi- sable to have a good layer of straw between the work and the boarding, and to place the boarding in the form of stone coping, to throw the water off equally on both sides. A number of very pleasing cornices and other ornaments may be formed in brickwork, by the mere disposition of the bricks, without cutting; and if cut, a simple chamfer will be sufficient. A great de- fect, however, is very often observable in these orna- ments, particularly in the bulging of arches over windows, which arises fi-om mere carelessness in rubbing the bricks too much on the inside ; whereas, if due care were taken to rub them exact to the gauge, their geometrical bearings being united, they would all tend to one centre, and produce a well- proportioned and pleasing effect. BUILDING. 149 PLASTERING. The plasterer is a workman to whom the decora- tive part of architecture owes a considerable portion of its effect, and whose art is requisite in every kind of building. The tools of the plasterer consist of a spade or shovel of the usual description ; a rake, with two or three prongs bent downwards from the line of the handle, for mixing the hair and mortar together; troicels of various kinds and sizes; stopping' and picking-ont tools; rules called straight edges; and wood models. The trowels used by plasterers are more neatly made than tools of the same name used by other artificers. The laying and smoothing tool consists of a flat piece of hardened iron, about ten inches in length, and two inches and a half wide, very thin, and ground to a semicircular shape at one end, but left square at the other ; and at the back of the plate, near the square end, is riveted a small iron rod with two legs, one of which is fixed to the plate, and the other to a round, wooden handle. With this tool all the first coats of plaster are laid on, as is also the last, or, as it is technically termed, the setting. The other kinds of trowels are made of three or four sizes, for gauging the fine stuff and plaster used in forming cornices, mouldings, &c. The longest size of these is about seven inches on the plate, which is of polished steel, about two inches and three quar- ters broad at the heel, diverging gradually from a point. To the heel or broad end a handle is adapted. The stopping and picking-ont tools are made of polished steel, of different sizes, though most gener- ally about seven or eight inches in length, and half an inch in breadth, flattened at both ends, and ground somewhat round. These tools are used in modelling and finishing mitres and returns to cornices; as, like- wise, in filling up, and perfecting the ornaments at the jomings. The straight edges are for keeping the work in an even or perpendicular line ; and the models or moulds are for running plain mouldings, cornices, &c. : of these latter, the plasterers require a greater number, as very little of his finishing can be done without them. Experienced workmen keep their tools very clean, and have them daily polished. Plasterers have technical divisions of their work, by which its quality is designated and value ascer- tained; as, lathing; laying; pricking up; lathing, laying, and set; lathing, floating, and set; screed, set, or putty ; rendering and set ; or rendering, floated, and set ; trowelled stucco, &c. ; each of which, here- after, we shall very minutely explain. In all the operations of plastering, lime exten- sively abounds ; we shall, therefore, first offer some observations on the properties of this important article. All who have written on the subject of lime, as a cement, have endeavored to ascertam what is the due proportion of sand for making the most perfect cem- ent ; but, with a little attention, it is evident that aU prescribed rules must be so very vague and un- certain, as to be of little utility to the workman ; for, besides the variation which is occasioned by a more or less degree of calcination, it is a certain fact, that some kinds of limestone are much more pinre, and contain a much smaller proportion of sand, thaa others ; consequently, it would be absurd to say that pure lime requires as small a proportion of sand, when made into mortar, as that which originally contained in itself a large proportion. The variation thus produced, in regard to the pro- portion of sand, is found to be extremely great. It is, however, stated that the best mortar which has come under examination was formed of eleven parts of sand to one of lime ; to which was added, by measure, between twice and thrice its own bulk of sand, which may be allowed to have been at least three times its quantity by weight. Supposing, therefore, that every particle of the lime had been so perfectly calcined as to be in a caustic state, there could not be less than forty-seven parts of sand to one of lime ; but it is hard to suppose that above one hundredth part of this mass, independent of the water, consisted of pure caustic calcareous earth. From these considerations, it is conceived that it is impossible to prescribe any determinate proportion of sand to lime, as that must vary according to the nature of the lime and other incidental circum- stances, which would form an infinity of exceptions to any general rule. But it would seem that it might be safely inferred that the moderns, in general, rather err in giving too little, than in giving too much, sand. It deserves, however, to be noticed, that the sand, when naturally in the limestone, is more inti- mately blended with the lime than can possibly be 150 BUILDING. ever effected by any mechanical operation ; so that it would be in vain to hope to make equally good mor- tar artificially from pm-e lime, with so small a pro- portion of caustic calcareous matter, as may some- times be effected, when the lime naturally contains a very large proportion of sand. Still, however, there seems to be no doubt, that if a much larger propor- tion of sand than is common were employed, and that more carefully and expeditiously blended and worked, the mortar would be made much more per- fect, as has been proved by actual experiments. Another circumstance, which greatly tends to vary the quality of cement and to make a greater or smaller proportion of sand necessary, is the mode of preparing the lime before it is beaten up into mortar. When for plaster, it is of great importance to have every particle of the limestone slaked before it is worked up ; for, as smoothness of surface is the most material point, if any particles of lime be beaten up before sufficiently slaked, the water still continuing to act on them, wUl cause them to expand, which will produce those excrescences on the surface of the plaster termed blisters. Consequently, in order to obtain a perfect kind of plaster, it is absolutely ne- cessary that the lime, before being worked, be allowed to remain a considerable time macerating or souring in water : the same sort of process, though not abso- lutely required, would considerably improve the lime intended for mortar. Great care is required in the management, the principal thing being the procur- ing of well-burnt lime, and allowing no more lime, before worked, than is just sufficient to macerate or sour it with the water : the best-burnt lime will re- quire the maceration of some days. It has been almost universally admitted, that the hardest limestone affords the lime which will consol- idate into the finest cement ; hence, it is generally concluded that lime made of chalk produces a much weaker cement than that made of marble or lime- stone. It would seem, however, that, if ever this be the case, it is only incidentally, and not necessarily. In making the mortar, other substances are occasion- ally mixed with lime, which wc shall here proceed to notice, and endeavor to point out their excellences and defects. Those commonly used, besides sand of various denominations, are powdered sandstone, brickdust, and sea shells; and for forming plaster where closeness, rather than hardness, is required, lime which has been slaked, and kept in a dry place till it has become nearly effete, and powdered chalk, or whiting, and gypsum, in various proportions, be- sides hair and other materials of a similar nature. Other ingredients have been more lately recom- mended, such as earthy balls, slightly burnt and pounded, old mortar rubbish, powdered and sifted, and various things of the like kind, the whole of which are, in some respect or other, objectionable. Plaster of Paris is employed by the plasterer to give the requisite form and finish to all the superior parts of his work. It is made of a fossil stone called gypsum, which is excavated in several parts of the neighborhood of Paris, where it derives its name, and is calcined to a powder, to deprive it of its water of crystallization. The stones are burnt in kilns, which are generally of very simple construction, being not unfrequently buUt of .the gypsum itself. The pieces to be cal- cined are loosely put together in a parallelopiped heap, below which are vaulted pipes or flues, for the application of a moderate heat. The calcination must not be carried to excess, as otherwise the plaster will not form a solid mass when mixed with a certain portion of water. During the process of calcination, the water of crystallization rises as white vapor, which, if the atmosphere be dry, is quickly dissolved in air. The pounding of the calcined fragments is per- formed sometimes in miUs constructed for the pur- pose, and sometimes by men, whose health is much impaired by the particles of dust settling upon their lungs. On the River Wolga, in Russia, where the burning of gypsum constitutes one of the chief occupations of the peasantry, all kinds of gypsum are burnt pro- miscuously on grates made of wood ; afterwards, the plaster is reduced to powder, passed through a sieve, and finally formed into small, round cakes, which are sold at so much per thousand. These balls are reduced into an impalpable powder by the plasterer, and then mixed with mortar. The less the gypsum is mixed with other sub- stances, the better it is qualified for the purpose of making casts, stucco, &c. The sparry gypsum, or selenite, which is the purer kind, is employed for taking impressions from coins and medals, and for making those beautiful imitations of marble, grahite, and porphyry, known by the name of scagliola, which is derived from the Italian word scagli. BUILDING. 151 Finely-powdered alabaster, or plaster of Paris, when heated in a crucible, assumes the appearance of a fluid, by rolling in waves, yielding to the touch, steaming, &c., all of which properties it again loses on the departure of the heat. If taken from the cru- cible and thrown upon paper, it will not wet it, but immediately be as motionless as it was before being exposed to the heat. Two or three spoonfuls of burnt alabaster mixed up thin with water will, at the bottom of a vessel filled with water, coagulate into a hard lump, not- withstanding the water that surrounds it. The coag- ulating or setting property of burnt alabaster will be very much impaired or lost if the powder be kept for any considerable time, and more especially in the open au-. When it has been once tempered with water, and suffered to grow hard, it cannot be ren- dered of any further use. Plaster of Paris, diluted with water into the con- sistence of a soft or thin paste, quickly sets, or grows firm, and, at the instant of its setting, has its bulk increased. This expansive property, in passing from a soft to a firm state, is one of its valuable properties, rendering it an excellent matter for filling cavities in sundry works, where other earthy mixtures would shrink and leave vacuities, or entirely separate from the adjoining parts. It is also probable that this ex- pansion of the plaster might be made to contribute to the elegance of the impressions it receives from medals, &c., by properly confining it when soft, so that, at its expansion, it would be forced into the mi- nutest traces of the figures. Other cements are iised by plasterers for inside work. The first is called lime and hair, or coarse stuff, and is prepared as common mortar, with the addition of hair from the tan yards. The mortar is first mixed with a requisite quantity of sand, and the hair is afterwards worked in by the appKcation of a rake. Next to this is fine stuff, which is merely pure lime, slaked first with a small quantity of water, and afterwards, without any extraneous addition, super- saturated with water, and put into a tub in a half fluid state, where it is allowed to remain till the water is evaporated. In some particular cases, a small por- tion of hair is incorporated. When this fine stuff is used for inside walls, it is mixed with very fine washed sand, in the proportion of one part sand to three parts of fine stuff, and is then caUed trowelled or bastard stucco, with which all walls intended to be painted are finished. The cement called ^augc stuff consists of three fifths of fine stuff" and one fifth plaster of Paris, mixed together with water, in small quantities at a time, to render it more ready to set. This composition is mostly used in forming cornices and mouldings run with a wooden mould. When great expedition is required, plasterers gauge all their mortars with plas- ter of Paris, which sets immediately. MASTIC CEMENT. This useful invention consists in making a cement or composition, which may be applied in the for- mation of ornaments and statues, and of bricks, or an imitation of bricks, tiles, and stones, and joining and cementing the same, and in erecting, covering, and decorating buildings internally and externally ; and the said cement or composition may be mixed and moulded upon any sort of material, and whole and entire erections and substances may be worked and moulded therewith. The cement consists in a mixture of earths and other substances that are insoluble in water, or nearly so, either in their natural state, or such as have been manufactured, as earthen ware, porcelain, and such like substances ; but it is preferred that those earths, either in their natural or manufactmred state, are the least soluble in water, and have, when pulverized, or reduced to powder, the least color. To the earth or earths as before named, either in their natural or man- ufactured state, and so pulverized, add a quantity of each of the oxides of lead, as litharge, gray oxide, and minium, reduced or ground to powder, and to the whole of the above-named substances a quantity of pulverized glass or flint stone These various earths, oxides, and glass, or flijit stone, reduced to a pulverized state, in proper and due pro- portions, and being mixed with a proper and due proportion of vegetable oil, as hereinafter named, form and make a composition or cement, which, by contact or exposure to the atmosphere, hardens and forms an impenetrable and impervious coating or covering, resembling Portland or other stones. The cement or composition is composed in the following manner and proportions : To any given 152 BUILDING. weight of earth or earths, commonly called pit sand, river sand, rock sand, or any other sand of the same or like nature, or pulverized earthen ware, or porce- lain, add two thirds of such given weight of the earth or earths commonly called Portland stone, Bath stone, or any other stone of the same or like nature, pulverized. To every five hundred and sixty pounds' weight of these earths so prepared add forty pounds' weight of litharge, prepared as before described, and, with the last-mentioned given weights, combine two pounds' weight of pulverized glass or flint stone. Then join to this mixture one pound weight of min- ium and two pounds' weight of gray oxide of lead. This compound of earths, oxide, and glass, or flint stone, put into a circular or other proper machine, that will, by its rotary or other motion, mix them well, and their proper intermixture may be ascertained by the shade or colors, which should appear of one even and regular shade or hue ; but any particular shade or color may be given by a proper selection of earths, or by adding a small quantity of vegetable, mineral, or other coloring matter. This composition being thus mixed, pass the same through a wire sieve, or dressing machine, of such fineness or mash as may be requisite for the purposes it is intended for, preferring a fine sieve, mash or wire work, when the composition is to be used for works of a fine or even surface. The composition thus formed and mixed is a fine dry powder, and may be kept open in bulk or in casks for any length of time without deterioration. When this composition is intended to be made into cement for any of the purposes described, it is spread upon a board or platform, or mixed in a trough ; and to every six hundred and five pounds' weight of the composition are added five gallons of vegetable oil, as linseed oil, v^^alnut oil, or pink oU. The composition is then mixed in a similar way to that of the mortar, and is afterwards subjected to a gentle pressure by treading upon it ; and this oper- ation is continued until it acquires the appearance of moistened sand. The mixture being thus com- posed is a cement fit and applicable to the enume- rated purposes. It is requisite to observe, that this cement should be used the same day the oil is added, otherwise it wiU fix or set into a solid substance, and be unfit for use. When this cement is to be used or applied to any thing, — to making of decorations, ornaments, and statues, or artificial bricks, tiles, and stones, — running or casting moulds, prepared, suited, and applicable for the purposes for which they are intended, are made use of. The moulds for making ornaments, statues, or other fancy works are prepared and made of gyp- sum, or plaster of Paris, or seasoned or dry wood, and must be prepared by rubbing the internal parts well with raw linseed oil, until they are brought to a dry, smooth, and polished surface, to prevent adhe- sion ; and in some instances, to obtain a more per- fect, dry, smooth, and polished surface, pulverized plumbago is used. In all cases it is requisite to de- tach or remove, with convenient speed, the mould from the body of the cement or composition to which it is intended to give form. The statue, ornament, bricks, tiles, and stones, or the imitations of all or either of them, thus formed, must be removed with care, and placed upon a bench or platform, which must be previously covered with fine dry sand to prevent adhesion ; and, in some cases, for statues and ornaments, a bed of fine dry sand is necessary to receive them, where they must remain in both cases for the purpose of setting for twenty-four hours, or a longer period, according to the temperature to which they are exposed. When it is applied for the purpose of cementing and joining of bricks, tiles, stones, and other sub- stances, the surfaces to which the cement or compo- sition is to be applied are prepared by brushing and cleaning them from dust and all loose matter ; the said surfaces are then covered with boiled linseed oil, with a brush, as in painting. This application of the boiled linseed oil prevents the too rapid ab- sorption of the oil employed or mixed with the cem- ent or composition. A thin coating of the cement is then applied between the two bodies to be joined. When the cement is used for the purpose of covering buildings intended to resemble stone, the surface of the buildings is washed in oil. The cement is then applied of the thickness of a quarter of an inch, or any greater thickness, accord- ing to the nature of the work, joint, or stone it is intended to resemble. It is requisite to observe, that when a joint, in- tended to resemble a plain stone joint, is to be made upon the surface of the cement or composition, the cement or composition must be partly set or hardened previously to the impression of the joint upon its sur- face, and the joint is made by a rule and steel jointer. BUILDING. 153 When the cement is used for the covering of sub- stances less absorbent than briclcs, or tiles, (as wood, lead, iron, or tin,) a much less quantity of boiled linseed oil in preparing the surfaces is required. LATHING, PLASTERING, &c. Lathinff, the fii-st operation, consists in nailing laths on the ceiling or partition. Laths are made of spruce or pine, and are fastened with cut nails. They are made in fom'-foot lengths ; and, with respect to their thiclaaess and strength, are either smgle, lath and half, or double. The single are the thinnest and cheapest ; those called lath and half are supposed to be one third thicker than the smgle ; and the double laths are twice that thickness. In lathing ceilings, the plasterers should so dispose them that the joints be as much broken as possible, that they may have the stronger key or tie, and thereby strengthen the plastering with which they are to be covered. The thinnest laths are used in partitions, and the strongest for ceilings. Latlis are also distinguished into heart and sap laths : the former should always be used in plain tiling ; the latter, which are of inferior quality, are most frequently used by the plasterer. Sawed laths have within a few years been inti-o- duced, and are nov/ in general use. They are not subject to so much waste, cost less, and do not re- quire so much mortar as the split lath; the last named, however, retains the mortar most firmly. Having nailed the laths in then- appropriate order, the plasterer's next business is to cover them with plaster, the most sim.ple and common operation of which is laying ; that is, spreading a single coat of lime and hair over the whole ceiling or partition, carefully observing to keep it smooth and even in every direction. This is the cheapest kind of plas- tering. Pricking up is performed in the same manner as the foregoing ; but it is only a preliminary to a more perfect Idnd of work. After the plaster is laid on, it is crossed all over V;dth the end of a lath, to give it a tie or key to the coat which is afterwards to be laid upon it. Lathing, laying, and set, or what is termed lath and plaster, one coat and set, is, when the work, after 20 being lathed, is covered with one coat of lime and hair, and aftei-^ards, when sufficiently dry, a thin and smooth coat is spread over it, consisting of lime only, or, as the workmen call it, putty or set. This coat is spread with a smoothing trowel, used by the work- man with his right hand, while his left hand moves a large flat brush of hogs' bristles, dipped in water, backwards and forwards over it, and thus produces a sm-facc tolerably even for cheap work. Lathing, floating and set, or lath and plaster, one coat, floated and set, differs from the foregoing, in having the first coat pricked up to receive the set, which is here called the floating. In doing this, the plasterer is provided with a substantial straight edge, frequently from ten to twelve feet in length, which must be used by two workmen. All the parts to be floated arc tried by a straight edge, to ascertain whether they be perfectly flat and level ; and whenever any deficiency appears, the hollow is filled up with a trowel full or more of lime and hair only, which is termed fllling out ; and when these preliminaries are settled, the screeds are next formed. The term screed signifies a style of Hme and hair, about seven or eight inches in width, gauged quite true, by drawing the straight edge over it until it be so. These screeds are made at the distance of about three or four feet from each other, in a vertical dh-cction, all round the partitions and walls of a room. When all are formed, the intervals are filled up with lime and hair, called by the workmen stuff, till flush with the face of the screeds. The straight edge is then worked horizontally on the screeds, by which aU the super- fluous stuff projecting beyond them in the intervals is removed, and a plain sm-face produced. This operation is termed floating, and may be applied to ceilings as well as to partitions or upright walls, by first forming the screeds in the dkcction of the breadth of the apartment, and filling up the intervals as above described. As great care is requisite to render the plaster sound and even, none but skilful workmen should be employed. The set to floated work is performed in a mode similar to that aheady prescribed for laying; but, being employed only for best rooms, is done with more care. About one sLxth of plaster of Paris is added to it, to make it set more expeditioiisly, to give it a closer and more compact appearance, and to render it more firm, and better calcidated to re- ceive the whitewash or color when dry. For floated 154 BUILDING. stucco work, the pricking up cannot be too dry ; but if the floating which is to receive the setting coat be too dry before the set is laid on, there will be danger of its peeling off, or of assuming the appear- ance of little cracks or sliclls, which would disfigiu-e the work. Particular care and attention, therefore, must be paid to have the under coats in a proper state of dryness. It may here be observed, that cracks, and other unpleasant appearances in ceilings, are more frequently the effect of weak laths being covered with too much plaster, or too little plaster upon strong laths, rather than of any sagging or other inadequacy in the timbers or the building. If the laths be properly attended to, and the plaster laid on by a careful and judicious workman, no cracks or other blemishes are likely to appear. The next operation combines both the foregoing processes, but requires no lathing ; it is called render- ing- and set, or rendering, floated, and set. What is understood by rendering, is the covering of brick or stone wall with a coat of lime and hair, and by set is denoted a superficial coat of fine stuff or putty upon the rendering. These operations are similar to those described for setting of ceilings and partitions ; and the floated and set is laid on the rendering in the same manner as on the partitions, &c., akeady ex- plained, for the best kind of work. Trowelled stucco, which is a very neat kind of work, used in dining-rooms, halls, &c., where the walls are prepared to be painted, must be worked upon a floated ground, and the floating be kept quite dry before the stucco is applied. In this process, the plasterer is provided with a wooden tool, called a Hoat, consisting of a piece of half-inch board, about nine inches long and three wide, planed smooth, with its lower edges a little rounded off, and having a handle on the upper surface. The stucco is pre- pared as above described, and afterwards beaten and tempered with clear water. The ground intended to be stuccoed is first prepared with a large trowel, and is made as smooth and level as possible ; when the stucco has been spread upon it to the extent of four or five feet square, the workman, with a float in his right hand and a brush in his left, sprinkles with water and rubs alternately the face of the stucco, till the whole is reduced to a fine, even surface. He then prepares another square of the ground, and pro- ceeds as before, till the whole is completed. The water lias the effect of hardening the face of the stucco. When the floating is well performed, it will feel as smooth as glass. Rovgh casting, or rough tvalling, is an exterior fin- ishing, much cheaper than stucco, and, therefore, more frequently employed on cottages, farm-houses, &c., than on buildings of a higher class. The wall in- tended to be rough cast is first picked up with a coat of lime and hair ; and when this is tolerably dry, a sec- ond coat is laid on, of the same materials as the first, as smooth as it can possibly be spread. As fast as the workman finishes this surface, he is followed by another 'with a pailful of rough cast, with v\'^hich he bespatters the new plastering, and the whole dries together. The rough cast is composed of fine gravel, washed from all earthy particles, and mixed with pure lime and water, till the whole is of a semi-fluid consistency. This is thrown from the pad upon the wall with a wooden float, about five or six inches long, and as many wide, made of half-inch board, and fitted with a round handle. While, with tliis tool, the plasterer throws en the rough cast with his right hand, he holds in his left a common wliite- washer's brush, dipped in the rough cast also, with which he brushes and colors the mortar and the rough cast he has already spread, to give them, when finished, a regular, uniform color and appearance. Cornices are either plain or ornamented, and some- times embrace a portion of both classes. The first point to be attended to is, to examine the drawings, and measure the projections of the principal mem- bers, which, if projecting more than seven or eight inches, must be bracketed. This consists in fixing up pieces of wood at the distance of about ten or twelve inches from each other, all round the place proposed for the cornice, and nailing laths to them, covering the whole with a coat of plaster. In the brackets, the stuff necessary to form the cornice must be allowed, which, in general, is about one inch and a quarter. A beech mould is next made by the car- penter, of the profile of the intended cornice, about a quarter of an inch iii thickness, with the quirks, or small sinkings, of brass or copper. All the sharp edges are carefully removed by the plasterer, who opens with his knife all the points v/hich he finds incompetent to receive the plaster freely. These preliminaries being adjusted, two workmen, provided vdth a tub of putty and a quantity of plas- ter of Paris, proceed to run the cornice. Before using the mould, they gauge screed of putty and BUILDING. 155 plaster upon the wall and ceiling, covering so much of each as will correspond with the top and bottom of the intended cornice. On this screed, one or two slight board straight edges, adapted to as many notches or chases, made in the mould for it to work upon, are naUed. The putty is then mixed with about one third of plaster of Paris, and brought to a semi-fluid state by the addition of clean water. One of the workmen, with two or three ti'owels full of this composition upon his liau'k, which he holds in his left hand, begins to plaster over the surface intended for the cornice, wuth his trowel, while his partner applies the mould to ascertain when more or less is wanted. When a sufficient quantity of plas- ter is laid on, the workman holds his mould firmly against both the ceiling and the wall, and moves it backwards and forwards, which removes the super- fluous stuff, and leaves an exact impression of the mould upon the plaster. This is not effected at once ; for while he works the mould backwards and forwards, the otlicr workman takes notice of any de- ficiencies, and fills them up by adding fi-esh supplies of plaster. In this manner, a cornice from ten to ttt^elve feet in length may be formed in a very short time; indeed, expedition is essentially requisite, as the plaster of Paris occasions a very great tendency in the putty to set ; to prevent which, it is necessary to sprinkle the composition frequently with water, as plasterers, in order to secure the truth and coiTectness of the cornice, generally endeavor to finish aU the lengths or pieces between any two breaks or pro- jections at one time. In cornices which have very large proportions, and in cases where any of the or- ders of arcliiteeture are to be introduced, three or four moulds are required, and are sim.ilarly applied, till all the parts are formed. Litcrnal and external mitres, and small returns or breaks, are afterwards modelled and filled up by hand. Cornices to be enriched with ornaments have cer- tam indentations, or sinldngs, left in the mould in which the casts are laid. These ornaments were formerly made by hand, but now are cast in plaster of Paris, from clay models. When the clay model is finished, and has, by exposure to the action of the atmosphere, acquired some degree of firmness, it is let into a wooden firame, and, when it has been re- touched and finished, the frame is fiUed with melted wax, which, when cold, is, by turning the frame up- side down, allowed to fall ofl', being an exact cameo. or counterpart of the model. By these means, the most enriched and curiously-wrought mouldings may be cast by the common plasterer. These wax mod- els are contrived to east about a foot in length of the ornament at once, such lengths being easily got out from the cameo. The casts are made of the finest and purest plaster of Paris, saturated with water; and the wax mould is oiled previously to its being put in. When the casts or intaglios arc first taken from tlie mould, they are not very firm ; but being suffered to dry a little, either in the open air or in an oven, they acquke sufficient hardness to allow of being scraped and cleaned. Basso rUievos and friezes are executed in a similar manner, only the wax mould is so made that the cast can have a back ground at least half an inch thick of plaster cast to the ornament or figure, in order to strengthen and secure the proportions, at the same time that it promotes the general effect. The process for capitals to columns is also the same, except that numerous moulds arc required to complete them. In tlic Corinthian capitals, a shaft or belt is first made, on which is afterwards fixed the foliage and volutes, the whole of which require dis- tinct cameos. In running cornices, which arc to be enriched, the plasterer takes care to have proper projections in the running moulds, so as to make a groove in the cor- nice for the reception of the cast ornament, v/hich is laid in and secured by spreading a siuall quantity of liquid plaster of Paris on its back. Detached orna- ments intended for ceilings or other parts, and where no running mould has been employed, are cast in pieces corresponding with the design, and fixed upon the ceiling, &c., with white lead, or with the compo- sition known by the name of iron cement. The manufacture of stucco has, for a long time past, attracted the attention of all connected with this branch of building, as well as chemists and other individuals ; but the only benefit resulting from such investigations is, a more extensive -knowledge of the materials used. It would seem that the gi-eat moist- m-e of our climate prevents its being brought to any high degree of perfection ; though, among the various compositions which have been tried and proposed, some, .comparatively speaking, are excellent. Common stucco, used for external work, consists of clean-washed river sand and ground lime, which are mixed dry, in the proportion of three of the latter to 156 BUILDING. one of the former : when well incorporated together, these should be secured from the air in casks till re- quired for use. Walls to be covered with this com- position must first be prepared, by raking the mortar from the joints, and picking the bricks or stones, till the whole is indented ; the dust and other extraneous matter must then be brushed off, and the wall well saturated with clean water. The stucco is supersat- luatcd with water till it has the appearance and con- sistence of ordinary whitewash, in which state it is rubbed over the wall with a flat brush of hogs' bris- tles. When this process, called roughing in, has been performed, and the work has become tolerably chy and hard, which may be known by its being more white and transparent, the screeds are to be formed upon the wall with fresh stucco from the cask, tem- pered with water to a proper consistency, and spread on the upper part of the wall, about eight or nine inches wide ; as also against the two ends, beginning at the top, and proceeding downwards to the bottom. Li this operation, two workmen arc required ; one to supply the stucco, the other to apply the plumb ride and sh-aight edge. When these are truly formed, other screeds must be made in a vertical direction, about fom" or five feet apart, unless apertures in the wall prevent it ; in which case, they must be formed as near together as possible. When the screcding is finished, compo * is prepared in larger quantities, and both the workmen spread it with their trowels over the wall, in the space left between each pair of screeds. When this operation is complete, the straight edge is applied, and dragged from the top to the bottom of each pair, to remove whatever super- fluous stucco may project above the screeds. If there be any hollow places, fresh stucco is applied, and the straight edge is again drawn over the spot, till the compo is brought even to the face of the screeds, and the whole is level with the edge of the rule. Another interval is then filled xip, and the workmen thus proceed till the whole of the wall is covered. The wall is finished by floating; that is, hardening the surface by sprinkling it with water, and rubbing it with the common wood float, which is performed similarly to trowelling stucco. This description of compo is frequently used by plasterers for cornices and mouldings, in the same manner as described in common plastering; but if * A name often given to Parker'i? cement. the workman finds it necessary, he may add a small quantity of plaster of Paris, to make it fix the better while running or working the mould. Such addition is not, however, calculated to give strength to the stucco, and is only made through the necessity of having a quick set. Scag-Uola is a distinct branch of plastering, dis- covered or invented, and much used, in Italy, and thence introduced into France, where it obtained its name. Columns and pilasters are executed in this branch of plastering in the following manner: A wooden cradle, composed of thin strips of pine or other wood, is naade to represent the column designed, but about two inches and a half less in diameter than the shaft is intended to be when finished. This cradle is lathed round, as for common plastering, and then covered with a pricking-up coat of lime and hair. Wlien this is quite dry, the artists in scagliola commence operations, by imitations of the most rare and pre- cious marbles, with astonishing and delusive effect ; indeed, as the imitation takes as high a polish, and feels as cold and hard, as the most compact and solid marble, nothing short of actual fracture can possibly discover the counterfeit. In preparing the scagliola, the workman selects, breaks, and calcines the purest gypsum, and as soon as the largest fragments, in the process of calcination, lose their brilliancy, withch-aws the fire, and passes the calcined powder through a very fine sieve, and mixes it, as required for use, with a solution of glue, isinglass, &c. In this solution, the colors required in the marble to be imitated arc diffused ; but when the work is to be of various colors, each color is prepared separately, and afterwards mmgled and combined, nearly in the same manner as a painter mixes oia his palette the primitive colors to compose his different tints. When the powdered gypsum is prepared, it is laid on the shaft of the intended column, over the pricked- up coat of lime and hair, and is then floated with moulds of wood, made to the requisite size : the artist iises the colors necessary to the imitation dm'ing the floating, by which means they mingle and incorpo- rate with the surface. To obtain the glossy lustre, so much admired in works of marble, the workman rubs the work with one hand with a pumice stone, while with the other he cleans it with a wet sponge ; he next polishes it with tripoli, charcoal, and a piece BUILDING. 157 of fine linen ; aftenvards with a piece of felt, dipped in a mixtnre of oil and tripoli ; and finally completes the work by the application of piu-e oil. This imita- tion is, certainly, the most complete that can be con- ceived ; and wlion the bases and capitals arc made of real marble, as is the common practice, the de- ception is beyond discovery. K not exposed to the weather, it is, in point of durability, little inferior to real marble, retains its lustre full as long, and is not one eighth of the expense of the cheapest kind. There is another species of plastering, used in the decorative parts of architecture, and for the frames of pictures, looking-glasses, &c., which is a perfectly distinct branch of the art. This composition, which is very strong, and, when quite dry, of a brownish color, consists of the proportion of two pounds of powdered whiting, one pound of glue in solution, and half a pound of linseed oil, mixed together, and heated in a copper, and stin-ed with a spatula till the whole is incorporated. When cool, it is laid upon a stone, covered with powdered whiting, and beaten till it assumes a tough and firm consistence ; after which it is covered with wet cloths, to keep it fresh till re- quu-ed for use. The ornaments to be cast in this composition are modelled in clay, as in common plastering, and af- terwards a cameo, or mould, is carved in boxwood. This carving requires to be done with the utmost care, otherwise the symmetry of the ornament which is to be cast from it will be sjjoUed. The composi- tion, when required for use, is cut with a knife into pieces of the requisite size and forced into the mould ; after which it is put into a press worked by an iron screw, and still further compressed. When the mould is taken from the press, the composition, which is generally cast about a foot in length, is dislodged from the mould, and the superfluous parts pared off with a knife and cast into the copper for the next supply. The ornaments thus formed are glued upon wooden grounds, or fixed by means of white lead, &c. ; after which they are painted or gUt, according to the pur- poses for which they are intended. This composition is at least 80 per cent, cheaper than carving, and, in most cases, equally calculated to answer all the pur- poses of the art. It is much to be wished, that the art of plastering could be restored to its ancient perfection, for the Romans possessed an art of rendering works of this kind much more firm and durable than can be ac- complished at the present time. The specimens of ancient Roman plastering still visible, which have not been injured by force, are found to be fnm and solid, free from cracks or crev- ices, and as smooth and polished on the surface as when first applied. The sides and bottoms of the Roman aqueducts were lined with this plastering, and endured many ages. At Venice, some of the roofs of houses and the floors of rooms are covered with a sort of plaster of later date, and yet sti-ong enough to endure the sun and weather for several ages without either cracking or spoiling. The method of making the Venetian composition is not known in England ; but such might probably be made by heating the powder of gypsum over a fire, and when boiling, which it wUl do without the aid of water or other fluid, mixing it with rosin, or pitch, or both together, with common sulphur, and the powder of sea shells. K these be mbced together, water added to it, and the composition kept on the fire till the instant of its being used, it is not improb- able that the secret may be discovered. Oil of tur- pentmc and wax, which are the common ingredients in such cements as are accounted firmest, may also be tried as additions, as also may strong alewort, which is by some directed to be used instead of water, to make mortar of limestone of more than ordinary strength. SLATING. This branch of building, which is principally em- ployed in the covering of roofs, is not unfi-equently combined with that of plastering. The slates chiefly used in London are brought from the quarries at Bangor, in Cacrnarvonshii-e, which supply all parts of the United Kingdom. Another kind of slate, of a pale blue-gi-een color, is used, and most esteemed, being brought from Kendal, in Westmoreland, called Westmoreland slates. These slates are not large, but of good substance, and weU calculated to give a neat appearance to a roof The Scottish slate, which as- similates in size and quality to a slate from Wales, called ladies, is in little repute. The slates produced in this country are principally from the quarries in the State of Vermont. In point 158 BUILDING. of durability, they are equal to the Welsh slates, but have not that uniformity of color which distinguishes the latter. The height of roofs at the present time is very rarely above one third of the sjian, and should never be less than one sixth. The most usual pitch for slates is that when the height is one foiu'th of the span, or at an angle of 26i degrees with the horizon. Taking this as a standard, the following table vn\l show the degree of inclination which may be given for other materials : — Kind of Covering. Inclination to tlie hori- zon. Height of roof in parts of span. Weiglit upon a square of roofing. Copper, . . . . 3 50 A 100 Lead, .... 3 50 -r'^ 700 Slates, large, . . 22 00 Iff J, 5 1120 Slates, ordinary, . . 26 33 1 f From 900 to 500 Stone slate, . . • 29 41 2380 Plain tiles, . . . . 29 41 -? 1780 Pan tiles, . . . . , 24 00 2 650 Thatch of straw or i eeds, 45 00 i Slaters class the "^ kVelsh and America) 1 slates in the following order : — Doubles, averag e size Ft. In. 11 b Ft. In y 6 Ladies, " a 1 3 8 Countesses, " (1 1 8 10 Duchesses, " u 2 1 Welsh rags, " a 3 2 Queens, '' (( 3 ' 2 Imperials, " Patent slate, « 11 2 2 6 6 2 2 The doubles are made from fragments of the larger kinds, and derive their name from their diminutive size. Ladies are similarly obtained. Countesses are a gradation above ladies ; and duchesses above coun- tesses. Slate, like most other stony substances, is separat- ed from its bed by the ignition of gunpowder. The blocks thus obtained arc, by the application of wedges, reduced into layers, called scantling-s, from four to nine inches in thickness, and of any requked length and breadth, which are afterwards sawed to the re- spective sizes by raachmery. The blue, green, and for buildings stables, and other purple, or darker kinds of slate, are, in general, found capable of being split into very thin laminae, or sheets ; but those of the white or brownish freestone land can seldom be separated or divided so fine ; consequently, these last form heavy, strong, thick coverings, proper in exposed situations, siich as barns, outhouses. The instruments used in splitting and cleaning slates are slate knives, axes, bars, and wedges ; the three first being vised to reduce the slates into the required thicknesses, and the last to remove the ine- qualities from the siuface. Imperial slating is particularly neat, and may be known by having its lower edge sawed ; whereas, all other slates used for covering are chipped square on their edges only. Patent slate was first brought into use by Mr. Wyatt, the architect; but a patent was never ob- tained. It derives its name from the mode adopted to lay it on the roofs ; it may be laid on a rafter of much less elevation than any other, and is considera- bly lighter, by reason of the laps being less than is necessary for the common sort of slating. This slat- ing was originally made from Welsh rag-s ; but it is now very frequently made from imperials, which ren- der it lighter, and also somewhat neater in appearance. Westmoreland slate, from the experiments made by the late Bishop of LlandafT, appears to differ a little in its natural composition from that obtained from Wales. It must, however, be remarked, that this kind of slate owes its lightness, not so mucli to any diversity in the component parts of the stone, as to the thinness to which it is reduced by the workman ; consequently, it is not so well calculated to resist violent winds as those which are heavier. Slates, when brought from the quarry, are not suf- ficiently square for the slater's use ; he therefore picks up and examines the slates separately, and observes Avhich is the sti-ongest and squarest end; then, seating himself, he holds the slate a little slant- ing upon, and projecting about an inch over, the edge of a small block of wood, which is of the same height as his scat, and cuts away and makes straight one of its edges ; then, with a slip of wood, he gauges and cuts off the other edge parallel to it, and squares the end. The slate is now considered pre- pared for use, with the exception of perforating through its opposite ends two small holes for the reception of the nails which are to confine it to the BUILDING. 159 roof. Copper and zinc nails, or iron nails tinned, arc considered the best, being less susceptible of oxida- tion than nails made of bar iron. Before we proceed fiu-thcr with the operations necessary in the slating of buildings, we shall give some account of the tools used by this class of ar- tificers. Slaters' tools are very few, whicli sometimes are found by the masters, and sometimes by the men. The tool called the saixe is made of tempered iron, about sixteen inches in length, somewhat bent at one end, with a handle of wood at the other. This tool is not unlilcc a large knife, except that it has on its back a projecting piece of iron, about three inches in length, drawn to a sharp point. This tool is used to chip or cut all the slates to the required sizes. The ripper is also of iron, about the same length as the saixe ; it has a very thin blade, about an inch and three quarters wide, tapered somewhat towards the top, where a round head projects over the blade about half an inch on each side; it has also two little round notches in the two internal angles, at their intersections. The handle of this tool is raised above the blade by a shoulder, which enables the workman to hold it firm. This instrument is used in repau-ing old slating, and the application consists in thrusting the blade under the slates, so that the head, which projects, may catch the naU in the little notch at its intersection, and enable Lhe workman to di-aw it out. During this operation, the slate is suffi- ciently loosened to allow of its beuig removed and another inserted in its place. The hammer, which is somewhat different in shape to the ordinary tool of that name, is about five inches in height on the hammer or driving part, and the top is bent back, and gi'ound to a tolerably sharp point, its lower or flat end, which is quite round, being about three quarters of an inch in diameter. On this side of the di-iving part is a small projection, with a notch in the centre, which is used as a claw to extract such nails as do not drive satisfactorily. The shaving tool is used for getting the slates to a smooth face for skirtings, floors for balconies, &c. It consists of an iron blade, sharpened at one of its ends like a chisel, and mortised through the centre of two round wooden handles, one fixed at one end, and the other about the middle of the blade. The blade is about eleven inches long and two inches wide, and the handle is about ten inches long ; so that they project about four inches on each side of the blade. In using this tool, the workman places one hand on each side of the handle that is in the middle of the blade, and allows tlie other to press against both his wrists. In this manner, he removes all the uneven parts from off the face of the slate, and gets it to a smooth surface. The other tools used by the slater consist of chisels, gouges, and files of all sizes ; by means of which he finishes the slates into mouldings and other required forms. Li slating roofs, it is necessary to form a base or floor for the slates to lay compactly and safely upon ; for doubles and ladies, boarding is requii-ed, which must be laid very even, with the joints close, and properly secm-ed by nails to the rafters. This being completed, the slater provides himself with several slips of wood, called tilling fdlets, about ten inches and a half wide, and three quarters of an inch thick on one edge, and chamfered to an arris on the other, which he nails down all round the extreme edges of the roof, beginning with the hips, if any, and if not, with the sides, eaves, and ridge. He next selects the largest of the slates, and arranges them regularly along the eaves, with their lower edges to a line, and naUs them to the boarding. This part of the work being completed, he takes other slates to form the bond to the under sides of the eaves, and places them under those previously laid, so as to cross and cover aU their joints. Such slates are pushed up lightly under those which are above them, and are seldom nailed, but left dependent for support on the weight of those above them, and then* own weight on the boarding. The countesses and all other de- scriptions of slates, when intended to be laid in a good manner, are also laid on boards. When the slater has finished the eaves, he stretches a line on the face of the upper slates, parallel to its outer edge, and as far from it as he deems sufficient for the lap of those he intends shall form the next course, which is laid and nailed even with the line, crossing the joints of the upper slates of the eaves. This lining and laying is continued close to the ridge of the roof, observing throughout to break the differ- ent joints, by laying the slates one above another. The same system is universally followed in laying aU the different sorts of slates, with the exception of those called patent slates, as hereafter explained The largest kind of slates are found to lay firm on 160 BUILDING. battens, which are, consequently, much employed, and produce a very considerable saving of expense in large buildings. A batten is a narrow portion of board, about two inches and a half or three inches wide, four of them being commonly procm'ed from an eleven-inch board. For countess slates, battens three quarters of an inch thick will be of adequate substance ; but for the larger and heavier kinds, inch battens will be necessary. In battening a roof for slates, the battens are not placed at a uniform distance from each other, but so as to suit the length of the slates ; and as these vary as they approach the apex or ridge of the roof, it follows that the slater himself is the best judge where to fix them, so as best to support the slates. A roof, to be covered with patent slates, requh-es that the common rafters be left loose upon then- pur- lines, as they must be so arranged that a rafter shall lie under every one of the meeting joints. Neither battening nor boarding is required for these slates. The number of rafters will depend on the width of the slates ; hence, if they be of a larger size, very few will suffice. This kind of slating is likewise commenced at the eaves ; but no crossing or bond- ing is required, as the slates arc laid uniformly, with each end reaching to the centre of the rafter, and butted up to each other throughout the length of the roof. When the eaves-course is laid, the slates which compose it are screwed down to the rafters by two or three strong inch and half screws at each of then- ends. A line is then sti-ained about two inches be- low the upper edge, in order to guide the laying of course, which is laid with its lower edge the next touching the line. This lining, layhig with a lap, and screwing down, is continued till the roof is com- pletely covered. The joints are then secured by fil- leting, which consists in covering all tlic meeting joints with fillets of slate, bedded in glaziers' putty, and screwed down through the whole into the rafters. The fillets are usually about three inches wide, and of a length proportionate to that of the slates whose joints they have to cover. These fillets are solidly bedded in the putty, and their intersecting joints are lapped similar to those of the slates. The fillets being so laid, and secm-cd by one in the middle of the fillet, and one in each lap, arc next neatly pointed all round their edges with more putty, and then painted over with the color of the slate. The hips and ridges of such slating are frequently covered by fillets, which produce a very neat effect ; but lead, which is not much dearer, is by far the best kind of covering for all hips and ridges. The patent slating may be laid so as to be perfectly water tight, with an elevation of the rafters considerably less than for any other slate or tile covering. The rise in each foot of length in the rafter is not required to be more than t«-o inches, which, in a rafter of fifteen feet, will amount to only two feet six inches — a rise scarcely perceptible from the gi-ound. Slating is performed in several other ways, but the prmciples aheady explained embrace the most of them. Some workmen shape and lay their slates in a lozenge form. This kind of work consists in get- ting all the slates to a uniform size, of the shape of a geometrical square. When laid on the roof, which must be boarded, they are bonded and lapped as in common slating, observing only to let the elbow, or half of the square, appear above each slate that is next beneath it, and be regular in the courses all over the roof. One naU or screw only can be used for such slating; hence it soon becomes dOapidated. It is commonly employed in places near to the eye, or where particular neatness is required. It has been ascertained that a slate one inch thick will, in a horizontal position, support as much in weight as five inches of Portland stone similarly sus- pended. Hence slates are now ^^^.■ought and used in galleries, and other pm'poses, where it is essential to have strength and lightness combmed. Slates are also fashioned into chimney-pieces, but arc incapable of receiving a polish like marble. It makes excellent sku'tings of all descriptions, as weU as casings to walls, where dilapidations or great wear and tear are to be expected. For these purposes, it is capable of being fLxed with joints, equally as neat as wood ; and may, if required, be painted over so as to appear like it. Staircases may also be executed in slate, which vrill produce a resemblance of marble. PLUMBING. Plumbing is the art of casting and working in lead, and using the same in the covering and for other purposes in building. To the plumber is also confided the pump work, BUILDING. 161 , as well as the making and forming of cisterns and reservoirs, large or small closets, &c., for the purposes of domestic economy. The plumber does not use a great variety of tools, because the ductility of the metal upon which he operates does not require it. The tools used consist of an iron hammer, rather heavier than a carpenter's, with a short, tliick handle ; two or three wooden mallets of different sizes, and a Iressing and flatting tool. Tliis last is of beech, about eighteen inches long and two inches square, planed smooth and flat on the under surface, and fouiaded on the upper, and one of its ends tapered off round as a handle. With this tool he stretches out and flattens the sheet lead, or dresses it to the shape required, using first the flat side, then the round one, as occasion may require. The plumber has also occasion for a jack and trying plane, similar to that of the carpenter. With this he reduces the edges of sheet lead to a straight line, when the purposes to which it is to be applied require it. His cutting tools consist of a variety of chisels and gouges, as well as knives. The latter of these are used for cutting the sheet lead into slips and pieces after it has been marked out by the chalk line. Files of difierent sizes ; ladles of three or four sizes, for melting the solder ; and an iron instrument called g-rozing irons. These grozing irons are of several sizes, generally about twelve inches in length, tapered at both ends, the handle end being turned quite round, to allow of its being firmly held whUe in use ; the other end is a bulb, of a spindle or spherical shape, of a size proportioned to the soldering intended to be ex- ecuted. They are, when required for use, heated to redness. The plumber's measm-ing ride is two feet iii length, divided into three equal parts of eight inches each ; two of its legs are of boxwood, duodecimally divided ; and the third consists of a piece of slow-tempered ^teel, attached to one of the box legs by a pivot on which it turns, and falls, when not in use, into a groove cut in such leg for its reception. This steel leg can be passed into places where the others can- not enter; and it is also useful for occasionally re- moving the oxide or any extraneous matters from the surface of the heated metal. Scales and weights are also necessary ; and he must be supplied with centre bits of all sizes, for the 21 purpose of making perforations in lead or Wood, through which he may want to insert pipes, &c. Compasses, to strike curcular pieces, to line or cover figures of that shape, are occasionally required. Lead is obtained from ore, and, from its being gen- erally combined with sulphur, it has been denomi- nated sulphuret. After the ore has been taken from its bed it is smelted, fust being picked, in order to separate the unctuous and rich or genuine ore from the stony matrice, and other impurities ; the picked ore is then pounded under stampers worked by ma- chinery, and afterwards washed to carry off the re- mainder of the matrice, which could not be separated in picking. It is next put into a reverberatory fur- nace to be roasted ; during which operation it is re- peatedly stirred, to facilitate the evaporation of the sulphur. When the surface begins to assume the appearance of a paste, it is covered with charcoal, and well shaken together ; the fire is then increased, and the purified lead flows down on all sides into the basin of the furnace, whence it runs off into moulds prepared for its reception. The moulds are capable of receiving one hundi-ed and fifty -four pounds of lead each, and their contents, when cool, are, in the commercial world, called pigs. Lead is of a bluish-white color, and when newly melted, or cut, is quite bright ; but it soon becomes tarnished on exposure to the atmosphere — assuming first a dirty, gray color, and afterwards becomes white. It is capable of being hammered into very thin plates, and may be drawn into wire ; but its tenacity is very inferior to that of other metals, for a leaden wire, the hundred and twentieth part of an inch in diameter, is only capable of supporting about eighteen pounds without breaking. Lead, next to tin, is the most fu- sible of all metals ; and if a stronger heat be applied, it boils and evaporates. If cooled slowly, it crystallizes. The change of its external color is owing to its gradual combination with oxygen, which converts its exterior surface into an oxide. This outward crust, however, preserves the rest of the metal for a long time, as the air can penetrate but very slowly. Lead is not acted upon immediately by water, though that element greatly facilitates the action of the air upon it ; for it is known that, when lead is exposed to the atmosphere, and kept constantly wet, the process of oxidation takes place much more rap- idly than it does under other circumstances ; hence the white crust that is to be obser\'ed on the sides of 162 BUILDING. leaden vessels containing water, just at the place where the surface of the water terminates. Lead is piurchased by plumbers in pigs, and they reduce it into sheets, or pipes, as they have occasion. Of sheet lead they have two kinds, cast and milled. The former is used for covering flat roofs of build- ings, laying of terraces, forming gutters, lining reser- voirs, &c. ; and the latter, which is very thin, for cov- ering the hips and ridges of roofs. This last they do not manufacture themselves, but purchase it of the lead merchants, ready prepared. For the casting of sheet lead, a copper is provided, and well fixed in masonry, at the upper end of the workshop, near the mould or casting table, which consists of strong boards, well jointed together, and bound with bars of iron at the ends. The sides of this table, of which the, shape is a parallelogram, vary in size from four to six feet in width, and from six- teen to eighteen feet and upwards in length, and are guarded by a frame or edging of wood, three inches thick, and four or five inches higher than the interior surface, called the shafts. This table is fixed upon firm legs, strongly framed together, about sLs or seven inches lower than the top of the copper. At the up- per end of the mould, nearest the copper, is a box, called the pan, which is adapted in its length to the breadth of the table, having at its bottom a long, hor- izontal slit, from which the heated metal is to issue, when it has been poured in from the copper. This box moves upon rollers along the surface of the rim of the table, and is put in motion by means of ropes and pulleys, fixed to beams above. While the metal is melting, the surface of the mould, or table, is pre- pared by covering it with a stratum of dry and clean sand, regularly smoothed over with a kind of rake, called a strike, which consists of a board about five inches broad, and rather longer than the inside of the mould, so that its ends, which arc notched about two inches deep, may ride upon the shafts. This being passed down the whole length of the table, reduces the sand to a uniform surface. The pan is now brought to the head of the table, close to the copper, its sides having previously been guarded by a coat of moistened sand, to prevent its firing from the heat of the metal, which is now put in by ladles from the copper. These pans, or boxes, it must be observed, are made to contain the quantity of melted lead which is re- quired to cast a whole sheet at one time ; and the slit in the bottom is so adjusted as to let out, during its progress along the table, just as much as wUl com- pletely cover it of the thickness and weight per foot required. Every thing being thus prepared, the slit is opened, and the box moved along the table, dis- pensing its contents from the top to the bottom, and leaving in its progress a sheet of lead of the desired thickness. When cool, the sheet is rolled up and removed from the table, and other sheets are cast, till all the metal in the copper is exhausted. The sheets thus formed are then rolled up and kept for use. In some places, instead of having a square box upon wheels, with a slit in the bottom, the pan con- sists of a kind of trough, being composed of two planks nailed together at right angles, with two tri- angular pieces fitted in between them at their ends. The length of this pan, as well as that of the box, is equal to the whole breadth of the mould. It is placed with its bottom on a bench at the head of the table, leaning with one side against it ; to the opposite side is fixed a handle, by which it may be lifted up in order to pour out the liquid metal. On the side of the pan next the mould are two iron hooks, to hold it to the table, and prevent it from slipping while the metal is being poured into the mould. The mould, as well as the pan, is spread over about two inches thick with sand sifted and moistened, and rendered perfectly level by moving over it the strike, and smoothing it down with a plane of polished brass, about a quarter of an inch thick and nine inches square, tiuned up on the edges. Before they proceed to casting the lead, the strike is made ready by tacking two pieces of old hat on the notches, or by covering the notches with leather cases, so as to raise the under side of the strike about an eighth of an inch or more above the sand, according to the proposed thickness of the sheet. The face or under side of the strike is then smeared with tallow, and laid across the breadth of the mould, with its ends resting on the shafts. The melted lead is then put into the pan with ladles ; and, when a . sufficient quantity has been put in, the scum is swept off" with a piece of board, and suffered to settle on the coat of sand, to prevent its falling into the mould when the metal is poured out. It generally happens that the lead, when first taken from the copper, is too hot for casting ; it is, therefore, suffered to cool in the pan till it begins to stand with a shell or wall on the sand with which the pan is lined. Two men ther BUILDING. 163 take the pan by the handle, or one of them takes it by means of a bar or chain fixed to a beam in the ceiling, and turn it down, so that the metal runs into the mould ; while another man stands ready with the strike, and, as soon as all the metal is poured in, sweeps it forward and draws the residue into a trough at the bottom, which has been prepared to receive it. The sheet is then rolled up as before. In this mode of operation, the table inclines in its length about an inch or an inch and a half, in the length of sixteen or seventeen feet, or more, accord- ing to the required thickness of the sheets : the thin- ner the sheet, the greater the declivity ; and vice versa. The lower end of the mould is also left open, to admit of the superfluous metal being thrown off. When a cistern is to be cast, the size of the four sides is measured out; and the dimensions of the front having been taken, slips of wood, on which the mouldings are carved, are pressed upon the sand. Figures of birds, beasts, &c., are likewise stamped in the internal area, by means of leaden moulds. K any part of the sand has been disturbed in doing this, it is made smooth, and the process of casting goes on as for plain sheets ; except that, instead of rolling up the lead when cast, it is bent into four sides, so that the two ends, when they are soldered together, may be joined at the back : the bottom is afterwards soldered up. The lead which lines the Chinese tea boxes is re- duced to a thinness which our plumbers cannot, it is said, approach. The following account of the pro- cess was communicated by an intelligent East Lidian, in a letter which appeared in the Gentleman's Mag- azine : " The caster sits by a pot containing the melted metal, and has two large stones, the lower one fixed and the upper one movable, having their surfaces of contact ground to each other, directly before him. He raises the upper stone by pressing his foot upon its side, and with an iron ladle pours into the opening a sufficient quantity of the fluid metal. He then lets fall the upper stone, and thus forms the lead into an extremely thin and irregular plate, which is afterwards cut into its required form." Cast sheet lead, used for architectural purposes, is technically divided into 5 lb., 5^ lb., 6 lb., 6^ lb., 7 lb., 7A lb., 8 lb., and S| lb.; by which is understood that every superficial foot is to contain those respec- tive weights, according to the price agreed upon. The milled lead used by plumbers is very thin, sel- dom containing more than five pounds to the foot. It is by no means adapted to gutters or terraces, nor, in- deed, to any part of a building that is much exposed either to great wear or to the effects of the sun's rays : in the former case, it soon wears away ; in the latter, expands and cracks. It is laminated in sheets of about the same size as those of cast lead, by means of a roller, or flatting mill. Lead pipes are sometimes made of sheet lead, by beating it on round wooden cylinders of the length and dimensions required, and then soldering up the edges. Solder is used to secure the joints of work in lead, which, by other means, would be impossible. It should be easier of fusion than the metal intended to be soldered, and should be as nearly as possible of , the same color. The plumber, therefore, uses what is technically called soft solder, which is a compound of equal parts of tin and lead, melted together and run into moulds. In this state it is sold by the manufacturer, by the pound. In the operation of soldering, the surfaces or edges intended to be united are scraped very clean, and brought close up to each other, in which state they are held by an assistant, while the plumber applies a little resin on the joints, in Order to prevent the oxida- tion of the metal. The heated solder is then brought in a ladle and poured on the joint ; after which it is smoothed and finished by rubbing it about with a red-hot soldering iron ; when completed, it is made smooth by filing. Li the covering of roofs or terraces with lead, (the sheets never exceeding six feet in breadth,) it be- comes necessary, in large surfaces, to have joints, which are managed several ways, but in all the chief object is to have them water tight. The best plan of effecting this is to form laps, or roll joints, which is done by having a roU or strip of wood about two inches square, but rounded on its upper side, naile-5 3 22-1 27-0 25-8 •M-8 4 39-3 47-9 45-8 (11-9 5 Gl-4 74-9 71-(i 90-7 6 88-4 107-8 103-0 139-3 7 120-3 14ti-8 140-2 189-f. 8 157-1 191-7 183-2 347-7 9 198-8 242-7 231-8 313-4 10 245-4 299-5 28G-2 387-0 WEIGHT OF CAST-IRON PIPES. This table shoivs the weiirht ot' pipes one foot long, of bores from 1 inch to 1"2 inches in diameter, advancinjr by one fourth of an inch; and of tiiickncsses from one fourth of an inch to one and one fourth inch, advancing by one eighth of an inch. Bore. K K U H « % 1 IH IH inch. lbs. lbs. lbs. lbs. lbs. lbs. lbs. lbs. lbs. 1 3-1 5-1 7-4 10-0 12-9 16-1 19-6 23-5 27-6 u 3-7 6-0 8-6 11-5 14-7 18-3 22-1 26-2 30-7 1* 4-3 6-9 9-8 13-0 16-6 20-4 24-5 29-0 .33-7 li 4-9 7-8 11-1 14-6 18-4 22-6 27-0 31-8 3G-8 2 5-5 8-8 12-3 16-1 20-3 24-7 29-5 34-5 39-9 2* 6-1 9-7 13-5 17-6 22-1 26-8 31-9 37-3 43-0 24 6-7 10-6 14-7 19-2 2:1-9 28-9 34-4 40-0 46-0 2} 7-4 11-5 10-0 20-7 25-7 31-1 36-8 42-8 491 3 8-0 12-4 17-2 22-2 27-6 3:3-3 39-3 45-6 52-2 3* 8-6 12-3 18-4 23-8 29-5 35-4 41-7 48-3 55-2 Si. 9-2 14-2 19-6 25-3 31-3 37-6 44-2 511 58-3 3? 9-8 1.5-2 20-9 26-9 33-1 39-7 46-6 53-8 61-4 4 10-4 16-1 22-1 28-4 35-0 419 49-1 56-6 64-4 4i 11-1 17-1 2;3-4 .30-0 36-9 44-1 51-6 59-4 G7-6 44 11-7 18-0 24-5 31-4 38-7 46-2 54 62-1 70-6 4| 12-3 18-9 25-8 a3-o 40-5 48-3 56-5 64-9 73-6 5 12-9 19-8 27-0 34-5 42-3 50-5 .58-9 67-6 76-7 5* 13-5 20-7 28-2 36-1 44-2 52-6 61-4 70-4 79-8 54 14-1 21-G 29-5 37-6 46-0 54-8 63-8 73-2 82-8 53 14-7 22-G 30-7 39-] 47-9 56-9 66-3 76-0 85-9 6 15-3 23-5 31-9 40-7 49-7 59-1 68-7 78-7 88-8 6.1 1(5-0 24-4 33-1 42-2 51-5 61-2 71-2 81-2 92-0 64 16-6 25-3 34-4 43-7 53-4 63-4 73-4 84.2 95-1 6J 17-2 26-2 35-6 45-3 55-2 65-3 76-1 87-0 98-2 7 17-8 27-2 36-8 46-8 56-8 67-7 78-5 89-7 101-2 7| 18-4 28-1 .38-1 48-1 58-9 69-8 81-0 92-5 104-2 74 19-0 29-0 39-1 49-9 60-7 72-0 83-5 95-3 107-4 7? 19-6 29-7 40-5 51-4 62-6 741 85-9 98-0 110-5 8 20-0 30-8 41-7 52-9 64-4 76-2 88-4 100-8 11:3-5 8;J 20-9 31-7 43-0 54-5 66-3 78-4 90-8 103-5 116-6 84 21-7 32-9 44-4 56-2 68-3 80-8 93-5 106-5 119-9 8* 22-1 33-6 45-4 57-5 70-0 82-7 95-7 109-1 122-7 9 22-7 34-5 46-6 .59-1 71-8 84-8 98-2 111-8 125-8 9} 23-3 35-4 47-9 60-6 73-6 87-0 100-6 114-6 128-9 94 2:^-9 .36-4 49-1 62-1 75-5 89-1 10:3-1 117-4 131-9 m 24-6 37-3 50-3 63-7 77-3 91-3 105-5 120-1 135-0 10 25-2 38-2 51-5 65-2 79-2 93-4 108-0 122-8 1:38-1 10^ 25-8 39-1 52-8 66-7 81-0 95-6 110-4 125-6 141-1 104 26-4 40-0 54-0 68-3 82-8 97-7 112-9 128-4 144-2 lOJ 27-0 41-0 55-2 ! 69-8 84-7 99-9 115-4 131-2 147-3 n 27-6 41-9 .56-5 71-3 86-5 102-0 117-8 1.33-9 1.50-3 lU 28-2 42-8 57-7 72-9 88-4 104-2 120-3 i:3G-7 153-4 1U 28-S 43-7 ,58-9 74-4 90-2 106-3 122-7 139-4 156-4 111 29-5 44-6 60-1 75-9 920 108-5 125-2 142-2 159-5 12 30-1 45-6 61-4 77-5 93-6 110-6 127 6 145-0 162-6 22 WEIGHT OF MET.VL PLATES. This table shows the weight of a square foot of different meta (dates, of thicknesses from one si.\tcenth of an inch to one inch, advancing by a sixteenth. Inch. Wrought Cast Cast Cast Cast Cast Cast Cast Iron. Iron. Copper. Brass. Lead. Zinc. Tin. Silver. IClbs. lbs. lbs. lbs. lbs. lbs. lbs. lbs. lbs. 1 2-5 2-3 2-9 2-7 3-7 2-3 2-4 3-4 2 5-1 4-7 5-7 5-5 7-4 4-7 4-7 6-8 3 7-6 7-0 8-G 8-2 11-1 7-0 71 10-2 4 10-1 9-4 11-4 11-0 14-8 9-4 9-5 13-6 5 12-7 11-7 14-3 13-7 18-5 11-7 11-9 17-0 6 1.5-2 14-0 17-2 16-4 22-2 14-0 14-2 20-5 7 17-9 16-4 20-0 19-2 25-9 16-4 16-6 23-9 8 20-3 18-8 22-9 21-9 29-5 18-7 19-0 27-:5 9 22-8 21-1 25-7 24-6 .^3-2 21-1 21-4 30-7 10 25-4 2.3-5 28-G 27-4 36-9 23-4 23-7 :34-l 11 27-9 25-8 31-4 30-1 40-G 25-7 26-1 37-5 12 30-4 28-1 31-3 32-9 44-3 28-1 28-5 40-9 13 32-9 ;50-5 37-2 35-6 48-0 30-4 30-9 44-3 14 35-5 32-9 40-0 38-3 51-7 32-8 33-2 47-7 15 38-0 35-2 42-9 41-2 55-4 3,5-1 35G 51-1 16 40-6 37-6 45-8 43-9 59-1 37-5 38-0 54-6 TIIE WEIGHT, IN POUNDS, OF A FOOT IN LENGTH OF CAST IRON inch. i 1* 15 14 -3* II f ? 6i Square. •781 1-756 3125 4-881 7-031 9-.56S 12-.520 1.5-818 19-531 23-e31 28-12.5 33-009| 38-281 43-943 -50-000 56-443 63-281 70-506: 78-120I 86-131: 94-531 103-318; 112-.500I 122058, Hexagon ■bio 1-528 2-703 4-225 085 8-281 10-815 13-990 16-900 20-450 24-340 28-565 33-131 38-031 43-271' 48-3531 54-7681 61-021 67-5151 74-549| 81-815 89-421 97-368 105-640 Octagon. Circle. -65U -012 1-471 1-387 2-603 2-454 4-065 3-8-54 5-8-56 5-.521 7-971 7-515 10412 9-815 iqiian-i bquore. di-l 13-lGS 16-2.561 19-6711 23-412 27-475 31818 3G-581 41-621 46-990 52-681 58-69(5 65 040 71-701 78 696 86-015 93-656 101-621 12-42.5 15-337 18-559 22-087 25-921 30-065 31-512 39-268 44-331 49-700 55-375 61-3.59 67-709 74-243 81-r2G 88 354 95-871 inch. 64 6J 7 7{ 7.-1 P 8] 84 9^* % 10 104 10.| lO^j u 11} in 11} 12 Hexagon 031 114-271 ,231 528 ■162 037 449 099 Octagon. 125 219 78l'201- 031 214- 968 257- 500 270- 318-281- .53l|'298- 131,312- 125,.327- 216342- ■281.357- 023373 ■000 389^ 087 177^ 412187 078!l99 078 210- 418 222- 100 234^ 105 247^ 471,2fl0^ 1.59 273^ 193'286' .5.59;300- 268,314- 315329- 693,344- 32-5 3.59 ■475.374 103-696 Ul-82.5 120-372 128-986 138-056 147-415 157-078 167-049 177-328 187-912 199-203 600 210-800 793,221-506 3151233-318 163,245-437 341 257-8.59 82s!270-593 646 283-633 796 296-978 310-631 324-587 338-8.56 353-428 OF TIIE MT3IGHT OF A CUBIC FOOT OF VARIOUS SUBSTANCES, In common Use for Building. lbs. Sand, solid 112-5 Sand, loose 95 Earth 93-75 Common Soil 124 Strong Soil 127 Clay 120 to 1.35 Clay and Stone 158 Brick 119 Granite 169 Marble 166 to 169 Sand, one cubic yard 3037 Common Soil, one cubic yard 3429 170 TABLES. THE NIT.MDER OP NAILS AND SPIKES TO THE POUND, Of various Sizes, as manufactured at the Troy Iron and .Vail Fac- tory, JV. Y. 1 Size of Number Boat Diam. No.Spikes Sliip Diam. No.Spikes Nail9. to the lb. Spikes. of Rod. to the lb. Spikes. of Rod. to the lb. 3 penny 600 No. 4 i 13 No. 4 A 8 4 " 3G0 " 5 tV 8 " 5 1 6 6 " 200 " 6 i 5 " 6 i 5 8 " 110 " 7 i 4 " 7 S 3i 10 " 88 " 8 1 3 12 " 68 " 9 T^if 2 20 « 40 " 10 t\ 14 FOE FINT)ING THE STRAIN THAT M.VY BE APPLIED TO A HEMPEN ROPE WITH S.VFETY. Circum- ference. Pounds. Circum- ference. Pounds. Circum- ference. Pounds. Circum- ference. Pownds. 1-00 200-0 3-00 1800-0 4-75 4512-5 6-50 8450-0 1-25 312-5 3-25 2112-5 5-00 5000-0 6-75 9112-5 1-50 450-0 3-50 2450-0 5-25 5512-5 7-00 9800-0 1-75 612-5 3-75 2812-5 5-50 6050-0 7-25 10512-5 2-00 800-0 4-00 3200-0 5-75 6612-5 7-50 112.50-0 2-25 1012-5 4-25 3G12-5 6-00 7200-0 7-75 12012-5 2-50 1250-0 4-50 4050-0 6-25 7812-5 8-00 12800-0 2-75 1512-5 WEIGHTS OP COPPER AND SPIKES Size. Weight of 1 Cop'r Bolts] per foot. Number of Composition Spikes to tlio 100 lbs. Weipht of Sheatbing Copper, and Yellow Sheatiiing Metal, per sheet. 4 i i 1 11 li lbs. -7567 1-18-24 1-7027 2-3176 3-0270 3-8312 4-9298 5 in. round head, 500 5 " square " 434 54" " " 400 6 « " " 377 64" " " 295 7 " " " 275 74" " " 210 8 " " " 200 84" " " 148 Size. Weight. Size. Weight. ounces. 14 16 18 20 22 lbs. ozs. 4 1 4 10 5 4 5 13 6 7 ounces. 24 26 28 30 32 lbs. ozs. 7 7 9 8 3 8 12 9 5 WEIGHT OF LEAD PIPES, TWELVE INCHES LONG. SHOWING THE CONTENTS OF BRICK WALLS, NO. OF BRICKS, &;c. This table is calculated in round numbers, and is not far from the average of waUs made of the Cliarlestown, Fresh Pond, or eastern bricks — the latter being about two tlurds tlie size of the two former. Width of Bricks Thickness No. of Bricks Contents of to a superficial of Wall, in to a superlicial Willi, in su- foot. inches. foot. perlicial feet. 1000 1 4 7 143 ii 2 8 14 71 ^^ 3 12 21 474 t( 4 16 28 354 (£ 5 20 35 28} (t 6 24 42 23} u 7 28 49 204 (( 8 32 56 17} (I 9 36 63 15} 1 cask of lime will plaster about 50 yards. 1 cask will skim about 200 yards. 4 casks will ordinarily employ 45 bushels of sand. 1 cask will ordinarily employ 5 pecks of hair. 00 yards of plastering will cover 1000 laths. 100 pounds of tlireeponny nails will lay 900 yards. § in, thick, from 1 to 3 inches bore. 1 in. thick, from 1 to 3 inches bore. s-ize. Weight Size. Weight Size. Weight Size. Weight Size. Weight Size. Weight. 1 2-19 li 3-64 24 5-09 1 4-85 1} 7-76 24 10-66 u 2-43 li 3-8;j 2S 5-a3 IJ 5-34 15 8-17 2g 11-15 li 2-66 2 4-12 2} 5-57 li 5-81 2 8-73 2} 11-63 15 2-91 2J 4-29 25 5-82 15 6-3 25 9-21 25 12-12 14 3-15 21 4-61 3 6-06 14 6-79 2i 9-7 3 12-61 11 3-39 21 4-t)2 lis 7-27 25 10-25 OF CYLINDRIC.VL ME.VSURES, Designed for the computation of the contents of lead pipes, from 1 inch diameter to 3 and upwards ; also, cisterns of 10 feet di- ameter and under ; and the quantity and weight of water in pumps, suction pipes, &c., of 1 inch diameter and upwards. Indies (liaiuetcr. Cubic feet and decimal parts. Ale gallons and parts. Wine gal- lons and parts. Weight of water in lbs. and parts. Dry bushels and parts. 1 •0055 -033 •04 •34 •0044 2 •0218 -134 •16 1^36 •0175 3 -0491 •301 ■37 3^06 •0394 4 •0873 ■534 -65 5^45 •0700 5 -136 -835 1-02 8-.52 •110 d. 6 -196 1-20 1-47 12-'27 •158 g 7 -207 1-64 2-00 16-70 •215 ■^ 8 -349 2-14 2-61 21-82 ■281 ° 9 -442 2-71 3-30 27-61 •355 ^ 10 •545 3-34 4-08 34-09 •438 S " •660 4-04 4-94 41-25 -530 :^ 12 •785 4-81 5-88 49-09 •631 ^ 24 S 36 3-14 19-25 23-52 196-.36 2-521 7-07 43-30 52-92 441-79 5-68 R 48 ■1 50 12-57 77-00 94-08 785-44 10-10 13-64 83-55 102-00 852-21 11-00 W 60 19-64 l'20-30 146-88 1-227-19 15-78 72 28-28 173-20 211-51 17(i7-15 22-72 84 38-49 235-81 287-88 2405-28 30-92 96 50-27 308-00 370-01 3141-,59 40-39 108 C):3-62 389-79 475-89 397608 51-12 120 78-54 481-25 587-.52 4903-74 63-11 N. B. If the diameter should fall between any of the numbers in the first column, the mean proportional contents may be found by adding the two contents between which it falls, and dividing by 2. Suppose it falls between 108 and 120 of the diameters, re- quired the wine gallons in 114 inches, or 9 feet 6 inches diameter, which falls between 587-52 and 475-89 2)106.3-41 Answer, 531-704 Or, if between 60 and 7"2, say 64 inches, or 5 feet 4 inches ; one third of 12 is 4 ; tlien required the cubic feet and parts. 28-28 Subtract 19-64 Divide Add 3)8-64 2-88 19-64 Answer, 22-52 Any depth may bo found, by multiplying by the depth any of the numbers in the contents; as, required the number of ale gal- lons in 24 inches diameter, at 6 feet deep. 19-25 6 Answer, 115-50 GLOSSARY OF ARCHITECTURAL TERMS Abacus The upper member of the capital of a column whereon the architrave rests. Scammozzi uses this term for a concave mouMing in the capital of the Tuscan pedestal, whicli, considering its etymol- ogy, is an error. Aedimest. The solid part of a pier, from which an arch springs. Acanthus. A plant called in English hears hrccch, whose leaves are employed for decorating the Corinthian and Composite capitals. The leaves of the acanthus arc used on the bell of the capital, and distinguish the two rich orders from tlic three others. Accompaniments. Buildings or ornaments having a necessary con- nection or dependence, and which serve to make a design more or less complete — a characteristic pcculiai-ity of ornaments. AccouPLEMENT. Among carpenters, a tie or brace ; sometimes the entire work, when framed. AcKOTEKiA. The small pedestals placed on the extremities and apex of a pediment. Admeasukement. Adjustment of proportions ; technically, an esti- mate of the quantity of materials and labor of any kind used in a budding. Alcove. The original and strict meaning of this word, which is derived from the Spanish atcoba, is that part of a bed-chamber in which the bed stands, and is separated from the other parts of the room by columns or pilasters. Amphiprostyle. In ancient architecture, a temple with columns in the rear, as well as in the front. AiipniTnEATRE. A double theatre, of an elliptical form, on the ground plan, for the exhibition of the ancient gladiatorial tights and other shows. Ajtcones. The consoles or ornaments cut on the keys of arches, sometimes serving to support busts or other figures. Annulet. A small, square moulding, which crowns or accompanies a larger. Also, that fillet which separates the flutings of a column. It is sometimes called a list, or listdla, which see. ANTiE. A name given to pilasters attached to a wall. Apophyge. That part of a column between the upper fillet of the base and the cylindi-ical part of the shaft of the column, which is usually curved into it by a cavetto. ABiEOSTYLE. That style of building in which the columns are dis- tant four, and sometimes five, diameters from each other ; but the former is the proportion to which the term is usually applied. This columnar arrangement is suited to the Tuscan order only. Akcade. a series of arches, of apertures, or recesses, a continued covered vault, or arches supported on piers or columns instead of galleries. In Italian towns, the streets are lined with arcades like those of Covcnt Garden and the Koyal Exchange. Ancn. An artful arrangement of bricks, stones, or other materials. in a curvilinear form, which, by their mutual pressure and support, perform the oflice of a lintel, and can-y superincumbent weights — the whole resting at its extremities upon piers or abutments. Arch Bcttress, or Flying Buttress, (in Gothic architecture,) an arch springing from a buttress or pier, and abutting against a wall. Archeion. The most retired and secret place in Grecian temples, used as a treasuiy, wherein were depo.