PLATE 1 .

G L A S S .VASE.
F.xhumed at Pompeii ,m 1839, and preserved in tits Museum at Naples.
M * »*«•««<*. a»i

CURIOSITIES
OF

GLASS MAKING:
WITH

DETAILS OF THE PROCESSES AND PRODUCTIONS OF ANCIENT
AND MODERN ORNAMENTAL GLASS MANUFACTURE.

BY

APSLEY PELLATT.

LONDON:
DAVID B O G U E , 86, F L E E T
MDCCCXLIX.

STREET.

ADVERTISEMENT.

THE

following brief Treatise originated in the

"LECTURES

UPON THE MANUFACTURE OF FLINT GLASS, AND THE CURIOSITIES OF GLASS-MAKING,"'

which I have had the honour to

deliver at the Royal Institution.
In collecting materials for this Lecture, I found it desirable
to examine a variety of evidences of the antiquity of the Art of
GLASS-MAKING,

when I at once became impressed with the

interest and importance of such memorials in illustrating the
history and progress of the invention.

Among such treasures

I number the exhumed relics in the British Museum, and
similar depositories of Art upon the Continent.

In the

former truly national establishment, and more especially in
the private specimens of ancient glass, under the care of Mr.
Doubleday, and the curator of the Medal Department of the
British Museum, I acquired invaluable aid in my researches.
It also affords me much pleasure to acknowledge my obligation to the Marquis of Northampton, Mrs. Richardson Aldjo
and Mr. Aldjo, Mr. Charles Roach Smith, Mr. Hamilton,

iv

ADVERTISEMENT.

and other eminent collectors, for access to their specimens,
which has afforded me facilities for arriving at the conclusions,,
historical, chemical, and manipulatory, now submitted to the
Header.
Such Facts and Curiosities in the History of Glass as have
come to my knowledge of late years, I have engrafted upon
my former Memoir " On the Origin, Progress, and Improvement of Glass Manufacture," published many years ago, but
long since out of print; and this constitutes the First Section
of the present Treatise.

The Second Section treats of the

Constituents and Manufacture of Glass, or in other words, of
Practical Glass-making.

And in the Third Section are de-

scribed and illustrated the various Manipulatory Processes of
the Art, more in detail than are to be found in any work on
Glass-making, ancient or modern, British or foreign.

The

practical illustrations consist of working diagrams, drawn in
the Glass-house; besides a very attractive Series of representations in colours, of Antique and Mediaeval Specimens,
including some of the Curiosities of Egyptian, Eoman,
Chinese, and Venetian Glass-making; and unquestionably
possessing highly artistic beauty, as well as evidence of ingenious manufacture.
It may be observed that the literature of the ancients
and middle ages affords but meagre information upon

ADVERTISEMENT.

V

the chemistry of colours, or other constituents of Glass;
and still less upon the modes of blowing, shaping, or moulding, this artistic manufacture.

One of the chief objects of

the present work is to supply this defect, by concentrating
within a practical focus the rays of information to be found
in the works of Neri, Merrett, Kunkell, Blancourt, Loisel,
Deaudenart, Bontemps, and others; and to blend with their
researches certain Curiosities of Glass Manufacture, familiar
to those practically engaged in Glass Works, but comparatively little known to amateurs of the Art, and those who take
interest in its very elaborate details; this portion of the
present volume being the result of my own experience and
investigation.
The value of researches into the skill of by-gone ages in
order to benefit the arts of our own time—more especially
with the powerful aid of the present state of chemical science
—is strikingly illustrated in Glass Manufacture.

But for

the existence of the Portland and Naples Vases, part of an
ancient Yase in the possession of Mrs. Aldjo, and some
interesting fragments from the ruins of Thebes, Pompeii,
Borne, and Boman London, we should have been unacquainted
with the high art of ancient Glass Cameo Engraving; and
many Glass colouring constituents and manipulatory processes
which now excite our admiration and imitation.

vi

ADVERTISEMENT.

It is hoped that the present work, besides being acceptable
to the Collectors of the Curiosities of Glass-making, may also
be welcomed by the Encouragers and Patrons of Art, and
Promoters of Science and Manufactures in general, to whom
these pages are respectfully dedicated,
By their obedient and devoted Servant,
APSLEY PELLATT.
Falcon Glass Works,
Holland. Street, Southwark.

CONTENTS.

PAGE

HISTORICAL NOTICES

1

CONSTITUENTS AND MANUFACTURE

33

FLINT GLASS

34

GLASS-HOUSE POTS

50

FURNACES

.

56

ANNEALING

62

COLOURED GLASS

73

STATE OF THE

FURNACE AT THE COMMENCEMENT

OF

THE WEEK'S WORK
MANIPULATIONS

79

.

80

TOOLS FOR MANIPULATION

81

MANIPULATORY PROCESSES:—
BLOWING AND MAKING BY HAND

84

WINE-GLASS IN THREE PIECES

84

WINE-GLASS, GOBLET, OR ALE-GLASS, IN TWO PIECES.
MODE OF PAYMENT, DIVISION OF LABOUR, ETC.
WASTE OF GLASS

. . .

.

86
87
92

TUMBLER

93

CYLINDRICAL LAMP-GLASS

94

RETORT

95

BLOWN-OFF DISHES

96

SCOLLOPING, OR CUTTING

96

HANDLED JUG

97

FRENCH LAMP-SHADE

99

Viii

CONTENTS.
PAGE

RINGED DECANTER

101

MOULDED BOTTLES

102

MOULDED ROMAN PILLAR

104

CANE AND TUBE DRAWING

106

VENETIAN FILIGREE GLASS

108

VENETIAN BALL

109

MILLE-FIORE

110

MOSAIC WORK

110

VENETIAN DIAMOND-MOULDED

112

VENETIAN VITRO DI TRINO

113

CASED GLASS

114

OLD VENETIAN FROSTED GLASS

116

WELDED COLOURED GLASS

117

CRYSTALLO ENGRAVING

118

CAMEO INCRUSTATION

119

AMERICAN PRESSED GLASS

121

DROP PINCHING

122

GLASS CUTTING

123

GLASS ENGRAVING

125

GLASS STOPPERING

127

GENERAL OBSERVATIONS

,

EXPLANATION OF THE COLOURED

. . .

128

PLATES:—

PLATE I.—NAPLES VASE
II.

131

THEBES FRAGMENTS, ETC

133

III.

ROMAN FRAGMENTS

136

IV.

ANCIENT VENETIAN SPECIMENS

139

V.—GRECIAN
VI.—ANCIENT

AND MISCELLANEOUS SPECIMENS .
MOSAIC,

SPECIMENS

CHINESE,

AND

.

140

VENETIAN
141

CUBIOSITIES OF GLASS-MAKING.

(Egyptian Glass-blowers. Page 3.)

Kfetorwal jgdttc^IN the whole range of human invention, it would be difficult
to point to a more ingenious or interesting result than the
Manufacture of Glass. " Although perfectly transparent itself/' says a popular illustrator of its history, " not one of
the materials of which it is made, partakes of that quality;"
a combination, which may, at the period of its invention, have
been as astounding as the identity of charcoal and the
diamond, established by the chemical philosopher of our time.
The art of making Glass is reputed to have been discovered
by accident. This inference is strengthened by the fact, that
it is scarcely possible to excite a fire of sufficient heat for metallurgical operation without vitrifying part of the bricks or
stones of the furnace. Of such imperfect vitrification, the
" Glass" occasionally dug up on the sites of buildings destroyed by great conflagrations, is a specimen.
B

2

CURIOSITIES OF GLASS-MAKING.

To the Phoenicians was long ascribed the good fortune of
the discovery. It is stated by Pliny, {Nat. Hist. lib. xxvi.
c. 26,) " that some mariners, who had a cargo of nitrum,
(salt, or, as some have supposed, soda,) on board, having
landed on the banks of the river Belus, a small stream, at the
base of Mount Carmel, in Palestine ; and finding no stones to
rest their pots on, they placed under them some masses of
nitrum, whichbeingfused by the heat, with the sand of the river,
produced a liquid and transparent stream: such was the origin of Glass/' However this may have been, the sand which
lay for about half a mile round the river, was peculiarly well
adapted for the making of Glass. The Sidonians, in whose
vicinity the discovery was made, took it up, and in process
of time, carried the art to a high degree of excellence; they
are even said to have invented Glass mirrors. It is, however,
a curious fact in the history of discovery, that the manufacture of Glass was, a few years since, unknown at Sidon,
where it is reputed to have been first invented.
The above account by Pliny is, in substance, corroborated
by Strabo, (xvi. 15,) and by Josephus, {Be Bell. Jud. ii. 9.)
Notwithstanding this explicit statement, it was long asserted that the ancients were unacquainted with Glass, properly
so called ; nor did the denial entirely disappear, even when
Pompeii presented evidences of the skill of the ancients in
Glass-making.
Our minute knowledge of Egypt, has, however, proved Glassworking to have been known by the Egyptians, at a very early
period of their national existence. Sir J. G. Wilkinson, in
his able work on the Manners and Customs of the Ancient
Egyptians, has adduced three distinct proofs that the art of

EGYPTIAN GLASS.

3

Glass-working was practised in Egypt before the Exodus of the
children of Israel from that land, three thousand five hundred
years ago. At Beni Hassan, are two paintings, representing
Glass-blowers at work (see p. 1);
and from the hieroglyphics
accompanying them, they are
shown to have been executed
in the reign of the first Osirtasen, at the early date above mentioned. In the same age, images of glazed pottery were common; proving the mode of fusing, and the proper proportions
of the ingredients for making Glass, to have been then known.
Lastly, Sir J. G. Wilkinson adduces the instance of a glass
bead, about three-quarters of an inch in diameter, and of the
same specific gravity as our crown Glass : this relic Captain
Hervey found at Thebes, and its date is proved by its bearing,
in hieroglyphic characters, the name of a monarch who lived
fifteen hundred years before Christ.* Such was the skill of the
Egyptians in Glass-making, that they successfully counterfeited
the amethyst and other precious stones worn as ornaments
for the person. Winckelmann, a high authority, is of opinion
that Glass was employed more frequently in ancient than in
modern times : it was used by the Egyptians even for coffins ;f
they also employed it not only for drinking vessels, but for
Mosaic work, the figures of deities, and sacred emblems,
in which they attained excellent workmanship, and surprising
brilliancy of colour.
It would be justifiable to suppose that the Hebrews brought
* See, in Plate No. 2, the specimens from Thebes,
f Within the year 1847, a process was patented in England for making
Coffins of Glass.

4

CURIOSITIES OF GLASS-MAKING.

Glass, and a knowledge how to manufacture it, with them out
of Egypt, were not the evidence of history so explicit that it
was actually discovered and wrought at their own doors.
Whether it was used by them for mirrors is another question.
That Glass, however, was known to the Hebrews appears
beyond a doubt. (Dr. Kitto's Gyclopadia of Biblical Literature; art. Glass.)
Notwithstanding so many records exist of the knowledge of
Glass-making possessed by the ancients, there remain but comparatively few specimens of antiquity to prove the fact. Most
writers have erroneously referred to the beads, which ornament
mummies, as satisfactory evidence of Egyptian Glass-making:
the majority of these, however, are composed, not of Glass,
but of burnt clay, or earthenware glazed; or, perhaps, of
glazed earthenware pounded, and mixed with coloured Glass,
fused together; of such substances are the numerous small
images of mummies, beetles, and other figures. There can,
however, be but little doubt that the Egyptians were well
acquainted with the materials for making Glass, as well as
with the chemical properties of the metallic oxides for colouring it; since, among the tombs at Thebes have lately been discovered small solid pieces of Glass, of a turquoise colour,
which are reasonably supposed to have been used for the
glazing of the earthenware beads and figures.
Fragments of blue, white, yellow, and green Glass, have
likewise been found; but these may possibly have been made
by the Greeks and Eomans, who successively conquered
Egypt; or, such specimens may have been procured from
neighbouring or distant nations. One of these fragments is
flat and of a circular form, resembling a coin; it is nearly
entire, of an amber colour, and has a well executed figure of a

EGYPTIAN GLASS.

5

lion impressed upon it in bas-relief. Another specimen is of
a green hue, and bears Arabic characters. The former is of
the size of a sixpence; the latter is as large as a half-crown
piece. Other specimens have been placed in our hands by Mr.
Bankes, the traveller in Egypt; and of these we have introduced
a coloured Plate, with a detailed description. The beauty,
variety, and arrangement of colours, not only place ancient
Glass manufactures high in our estimation as to taste and
design, but the knowledge of the chemical art in opaque
and transparent colouring which they evince, deserves to be
appreciated, particularly their blues, without cobalt or nickel,
and their reds without gold.* It was, however, formerly
doubted whether the makers of these specimens were aware of
the use of lead as a solvent of white Glass. (See page 7.)
It is certain that the Glass-houses of Alexandria were celebrated among the ancients for the skill and ingenuity of their
workmen; and from thence, the Komans, who did not acquire
a knowledge of the art till a later period, procured all their
Glass-ware. Most of the large, greenish Glass cinerary vases
in the British Museum, found in Eoman barrows which contained bones and bone-ashes, are, probably, the production
of extensive Egyptian or Eoman works : they are large, and
of excellent form and workmanship: but the Glass is somewhat impure, of a greenish tint, has numerous globules and
strice (see PLATE), and is not unlike the modern common
crown or sheet Glass in quality.f Strabo relates, that a Glassmaker of Alexandria informed him, that an earth, (pro* See Klaproth's analysis.
f Although remains of ancient Roman Potteries have been exhumed in
Great Britain, it does not appear that any traces of subterranean Glasshouses or works have been discovered.

6

CURIOSITIES OF

GLASS-MAKING.

bably manganese,) was found in Egypt, without which, the
valuable coloured glass could not be made. It is also related
that the Emperor Hadrian received as a present from an
Egyptian jDriest, several Glass cups, sparkling with every
colour; these, as costly wares, were ordered to be used only
on grand festivals.
We have incidentally mentioned the discovery of Glass at
Pompeii. Glass vessels have, also, been found among the ruins
of Hereulaneum; and it appears that Glass was used for admitting light to dwellings in Pompeii,* although other houses
had window-frames filled with a kind of transparent talc.f
In the reign of Tiberius, a Eoman artist had, according to
Pliny, his house demolished—according to other writers, he was
beheaded—for making Glass malleable. The Pompeian and
Eoman architects are known to have used Glass in their Mosaic
decorations; of these, remains have been found among the
ruins of the villa of the Emperor Tiberius, in the island of Capri.
Several specimens, also, are yet to be seen in Westminster
Abbey, cemented into the sides of the tomb of Edward the
Confessor. They are flat pieces, about a quarter of an inch
thick; the under layer has a reddish, granulated appearance,
* Mr. Auldjo, of Noel House, Kensington, who resided several years at
Naples, states, that he has seen Glass in the window-frames of some of the
houses of Pompeii. Mr. Roach Smith has a specimen of ancient flat Glass;
such as he helieves to have been used by the Romans, or their predecessors,
for windows.
f Glass, melted and cast into plates, is said by St. Jerome to have been
used in his time, (A.D. 422,) to form windows. About a century later,
Paulus Silentiarius mentions the windows of the church of St. Sophia, at
Constantinople, which were covered with glass ; and from this period, frequent allusions to the similar use of glass are met with in various authors.-—
Treatise on Glass: Cabinet Cyclopcedia.

ROMAN GLASS.

7

and is perfectly opaque; whilst the upper surface is of white
transparent glass. Between the' two, is a very thin layer of
gold-leaf—the whole being fused into one substance. This
description of gilded Glass was, no doubt, highly valued; and
the perfect state in which it is found, affords a convincing
proof that the art of Glass incrustation was, to a certain extent, known to the ancients. The pieces which have hitherto
been met with are, for the most part, about an inch square, or
of the same size in a diamond form.
During the reign of Nero, great improvements were made
in Koman Glass. The perfectly clear Glass, which bore the
nearest resemblance to crystal, was so highly valued, that Nero
is stated to have given for two cups, of no extraordinary size,
with two handles, 6000 sestertia, or nearly i£50,000 sterling.
The superior kinds of Glass were in such extensive use, in the
time of Pliny, as to have almost superseded cups of gold and
silver. Hence, the manufacture would appear to have been confined chiefly to articles of luxury—such as vessels of glass to
imitate precious stones, intended for cutting by the lathe, by
Koman artists, or Grecian artists resident in Eome, in the
style of cameos in relief. In the British Museum are preserved
many specimens of fragments of vases, and small pieces
of white opaque enamel Glass, upon blue and amethyst
transparent grounds, supporting the probability of this
opinion. White crystal Glass, without lead, cut to imitate
rock-crystal, was then known; although the introduction of
lead into white glass was, till recently, considered to be of
British origin.* (See PLATE 3, fig. 3.)
* A few pieces of white cut Glass, of Roman manufacture, have been
found, without lead; their specific gravity being only 2.049, whereas Flint-

8

CURIOSITIES OF GLASS-MAKING.

A few small specimens of Eoman Glass have been preserved
in the British Museum. One of them was of an octagon form,
of light azure blue, which crumbled to fragments on being
exposed to the air and light; it had a dull appearance, and the
crumbling of the particles without friction, was caused by an
excess of alkali, gradually exuding for many years, until the
cohesion of the crystals was destroyed. Trade secrets in the
preparation of Glass for gems* most likely existed in ancient
times; for very little has been written by Egyptian, Greek, or
Koman authors on the chemical constituents of Glass gems, or
cameo-engraved vases. Glass in solid pieces, such as gems and
mosaics, was, probably, manufactured in small Glass-houses;
and the secrets of the processes may have passed from father
to son for several successive generations. The Glass-makers of
Eome had a street assigned them in the first region of the city.
A tax was, also, laid upon them by Alexander Severus, which
existed in the time of Aurelius, and probably long after.f
Glass-making in Britain is supposed to be of very ancient
date; if the opinion of Pennant be well founded, of a period
prior to the Norman Conquest. The art of manufacturing
Glass into such ornaments as beads and annulets, was certainly
known to the Druids; and Glass vessels were made by the
Anglo-Saxons.;);
Glass of the usual density, is about 3.200 to 1.000 of water. Subsequently, other pieces of Glass have been exhumed in the city of London;
these are considered, by Mr. Roach Smith, to be ancient Boman; one small
piece is of 2.600, and another 3.144, specific gravity. (See remarks in
. the after part of this work.)
* See Plate 6, fig. 6.
f A sort of ancient excise, highly injurious to industrial art, and, probably, one of the causes that transferred the Glass manufacture to Venice.
J See sketch and description of an Anglo-Saxon vase, in No. 8, page
347, of the Journal of the British Archaeological Association.

DRUIDICAL GLASS.

9

Near Alberfraer Palace, in Wales, have frequently been found
the Glain JSfezdyr, or Druid Holy Snakes. Of these, the vulgar
opinion was,* that they were produced by snakes joining their
heads together, and hissing; that by such means, a kind of
bubble like a ring was formed round the head of one of them,
which the rest, by continual hissing, blew on till it came off
at the tail, when it immediately hardened into a ring. Whoever found one of these " snake-stones," was to prosper in all
his undertakings. Such Glass annulets are generally about
half as wide as our finger-rings, but much thicker. They are
usually of a green colour; but, some are blue, and others are
curiously variegated with waves of blue, red, and white. They
are, in fact, beads of Glass, which were used by the Druids as
a charm to impose upon the vulgar.— {See page 12.)
Dr. Stukeley gives an account of a curious Glass vase, found
near a body that was dug up at Chatteris, in the Isle of Ely:
its exact figure, unfortunately, could not be ascertained, as it
was broken; but Dr. Stukeley remarks: " What, I believe,
our present Glass-makers cannot perform, many pipes proceeded from it but closed; I think ten in number. I never
saw one like it, nor can I conjecture what its purpose was."
Camden records: " On the commons about Winstre, are
several barrows: in the largest were found two Glass vessels,
between eight and ten inches high, with wide round mouths,
containing about a pint of clear, greenish water; also, red
Glass beads, and other ornaments and trinkets."f
Mr. C. Eoach Smith, Secretary to the Archaeological Asso^
* Camden's Britannia, vol. ii. p. 750* An account of this anguinum
ovum, or serpents' egg, is given by Pliny—Nat. Hist. lib. xxix. c. 3.
t Camden's Britannia, vol. ii. p, 311, Derbyshire.
C

10

CURIOSITIES OF GLASS MAKING.

ciation, possesses several of these beads. This indefatigable
antiquary has, likewise, some fragments of Koman Glass, dug
up in the city of London; they have projecting pillars outside,
while the interior is not indented, but smooth; these pillars
have been formed, partly by moulding, and partly by rapid rotation, increasing the projection on the principle of centrifugal
force: the remainder are portions of a vase-shaped basin of elegant form. (See PLATE 3, figs. 1,2.) Several other Eoman specimens of this kind are to be seen in the Museum at Boulognesur-Mer. English Glass-makers, until this discovery, considered
the patent pillar, (as it is called,) to be a modern invention. A
Koman vase thus made is to be seen entire at the Polytechnic
Institution, in Eegent-street; it is a complete specimen of
pillar moulding, but the pillars are very much less in width
and projection than some of those at Boulogne, and in Mr.
Eoach Smith's collection. (See PLATE 5, fig. 2.)
The Aggry beads of Ashantee, as involving points of
manufacture analogous with the above specimens, may be
noted here. Mr. Bowdich, during his visit to that country,
procured some of these Aggry beads, which the natives invariably declare to be " found in the Dinkira, Akim, Warsaw,
Ashanta, and Fantee countries, the greatest number in the
former, being the richer in gold. They say they are directed to
dig for them, by a spiral vapour issuing from the ground, and
that they rarely lie near the surface. Those of inferior beauty
frequently fetch a large price, from having been worn by some
royal or eminent character." Dr. Leyden describes the
" Aigris, a stone of a greenish blue colour, supposed to be a
species of jasper, small perforated pieces of which are valued
at their weight in gold, and stated to be used as for money."
Dr. Leyden, however, considers this to refer to the Popo

AGGRY BEADS OF ASHANTEE.

11

bead; though that is semi-transparent, of a bright blue, resembling cornelian, (which is frequently found in these
countries,) and said to be obtained in the same manner as the
Aggry bead. Isert describes them (i as a sort of coral, with
inlaid work." " The art of making beads/' (says Mr. Bowdich,)
" is entirely lost, or was never known in these parts. It is not
" improbable that, in the golden age of Egypt, she had comCf
munication with the Gold Coast; indeed, it has been thought,
" and perhaps not without some reason, that the Gold Coast is
i(
the Ophir of Solomon.* The variegated strata of the Aggry
" beads are so firmly united, and so imperceptibly blended,, that
" the perfection seems superior to art: some resemble Mosaic
" work; the surfaces of others are covered with flowers and re" gular patterns, so very minute, and the shades so delicately
" softened one into the other, and into the ground of the bead,
" that nothing but the finest touch of the pencil could equal
" them. The agatized parts disclose flowers and patterns, deep
" in the body of the bead ; and thin shafts of opaque colours,
" running from the centre to the surface. The natives pretend
" that imitations are made in the country, which they call boiled
" beads, alleging that they are broken Aggry beads, ground into
" powder and boiled together, and that they know them because
" they are heavier; but this 1 find to be mere conjecture among
" themselves, unsupported by anything like observation or dis" covery. The natives believe that, by burying the Aggry beads
" in sand, they not only grow but breed. The colouring matter
" of the blue beads has been proved by experiment to be iron ;
" that of the yellow, without doubt, is lead and antimony, with
" a trifling quantity of copper, though not essential to the pro* See Plate 2, figs. 8 to 15.

12

CURIOSITIES OF GLASS-MAKING.

" duction of the colour. The generality of these beads appear
{C
to be produced, from being coloured in thin layers, afterwards
" twisted together in a spiral form, and then cut across ; also
" from different coloured clays raked together without blending;
ff
how the flowers and patterns in the body, and on the surface
" of the rarer beads, have been produced, cannot be so well ex" plained. Besides the suite deposited in the British Museum,
i(
I had the pleasure of presenting one of the most interesting
" kind to Baron Humboldt; and I have also sent one to Sir
" Eichard Hoare, as it seemed to correspond so closely with the
" bead which he found in one of the barrows, and describes as
*'follows, in his History of Wiltshire:—•' The notion of the
" rare virtues of the Glain Neidyr, as well as of the continued
^ good fortune of the finder, accords exactly with the African
" superstition. A large Glass bead, is of the same imperfect
" petrifaction as thePully beads, and resembles also, in matters,
" little figures that are found with the mummies in Egypt, and
" are to be seen in the British Museum. This very curious
se
bead has two circular lines, of opaque sky-blue and white,
" and seems to represent a serpent entwined round a centre,
4f
which is perforated. This was certainly one of the Glain
" Neidyr of the Britons; derived from Glain, which is pure and
" holy, and Neidyr, a snake.'"
Some interesting specimens of Roman and early British
glass may be mentioned here. Not long since, there were
sent to the Archaeological Institute, a fragment of a glass
vessel, supposed to be of Eoman date, discovered at Lavenham, in Suffolk. In the central part was inclosed a small
quantity of liquid, half filling the cavity; it was slightly tinged
with a pinkish colour, and seemed to deposit a whitish sedi-

SAXON GLASS.

13

ment. The Glass was of a pure white crystalline texture.
Stow relates that amongst numerous Eoman remains found
when the ancient field, called Lolesworth, now Spittlefield,
was broken up, about the year 1576, to make bricks, " there
were found divers phials, and other fashioned glasses, some
most curiously wrought, and some of crystal, all which
had water in them/' Others had " oyle in them, very thick
and earthly in savour." (Survey of London, b. ii. c. 5, p. 177,
ed. 1633.) In the Museum of Antiquities, at Eouen, a small
Glass vessel, accounted to be Eoman, is preserved, hermetically
sealed, and half full of liquid. (ArchoeologicalJournal, No. 9.
March, 1846.)
Early in 1847, there were found, in digging at Cuddesden,
the episcopal palace of the Bishop of Oxford, several human
skeletons ; and near them were two sword-blades, some bronze
fragments, and two small glass vases. The latter are of a
very pale blue transparent glass; the surface has become
iridescent from decomposition, and this, in the larger one,
gives it a streaked appearance. The larger vase is 3 inches deep,
by 5-J inches in diameter, and is ornamented on the sides
with three waved lines touching at the projections; underneath is a figure, much resembling the cusping of a circular
window. The other vase is 4§ inches in diameter. The
pattern on both is produced by thick threads of glass, applied
to the surface while melted. These vessels are conjectured to
be of the Saxon period, and to be of as early a date as the
fifth or sixth century. Curious Glass vessels, apparently
drinking-cups, have also been occasionally discovered, ornamented, like the Cuddesden vases, with threads of Glass,
attached to their surface when in a molten state, forming

14

CURIOSITIES OF GLASS-MAKING.

spiral, wavy, and zig-zag lines, in relief, or converging towards
the centre of the bottom of the vase; a vessel shaped like
a bell, was discovered in Minster church-yard, in the Isle
of Thanet, placed on the skull of a skeleton, the mouth downwards ; another, of very singular form, was found in a similar
position, at Castle Eden, Durham; and a third, of conical
shape, ornamented with spiral and wavy lines, in relief, was
found, with human remains and weapons, at Denton, in Buckinghamshire. (Arc/icBOlogical Journal, No. 14, June, 1847.)
In 1846, there was exhibited to the Archaeological Institute,
an ancient bead, believed to have been found near Headington,
Oxford. The substance of this bead appears almost black;
but, when held to the light, it is found to be a beautifully
clear deep green Glass; the surface of it is richly varied with
splashes of white enamel, mixed with blue, radiating from the
centre, and slightly contorted, particularly on the under side.
The enamel penetrates some distance into the substance of the
Glass, and appears to have been thrown on the mass, while
in a soft state; it was then, probably, slightly twisted, and
its globular form flattened between two plane surfaces. It is
not perforated, and only slightly depressed in the centre.
Another bead, of similar character to the above, found in
the bed of a stream, which flows near the British camp of
Madmarston, is preserved in the Ashmolean Museum. Here,
also, is a curious series of beads, which belonged to the original collection of Elias Ashmole, or to that added by Dr.
Plot. Among them, is a bead similar to that above described,
except that the body is not of fine green, but more like the
common modern bottle-glass; the markings are of white and
blue enamel. Here are, likewise, two imperforate beads, or

CHINESE

GLASS.

15

balls, one of smoke-coloured, and the other of light brown,
Glass; and both ornamented with lines of white enamel radiating spirally from the centre. Among the perforated
beads, are many curious varieties, and great diversity in the
colour of the Glass; there are some entirely colourless, and
others approach nearly to it. Some of the enamelled specimens are formed of concentric layers of different colours ;
and the facets are cut across these, and thus produce a variety of
waved lines. Another has an imitation of stones of different
colour, being set in studs on its surface; and a third is ornamented with small raised and twisted coral-work. Indeed, the
whole collection, from the diversity in form, material, colour,
and design, which it exhibits, is well deserving of a careful
examination. (ArcluBologicalJoiirnal^o. 12, December, 1846.)
Glass engraving in its modern acceptation—viz., roughed
and polished in intaglio,—was probably unknown to theKomans
and their predecessors. The art of cutting Glass in relief,
was, however, known to them at very remote periods; for
which purpose, as we learn from Pliny, (Nat. Hist, xxvii. c.
4,) the diamond was used.
The Chinese have long been skilled in Glass-making. M, Abel
Bemusat states,* that their imitation of the precious stone
Yeschm was so excellent, that it was almost impossible to distinguish the artificial from the real. This description of Glass-ware
was manufactured into vases of various forms by the Chinese,
from whom the Arabians procured them. Some were of a clear,
* Histoire de la Ville de Khotan, tiree des annales de la Chine, et traduite
de la Chinois; suivie de recherches sur la substance minerale, appellee par
les Chinois, Pierre de Ju, et sur le Jaspe des Anciens. Par M. Abel
Remusat, pp. 153 — 159.

la

CURIOSITIES OF GLASS-MAKING.

transparent white, extremely brilliant, and as pure as a precious stone ; and others of a beautiful blue, and equally pure.
In Egypt and Syria, no difference was known between the real
and artificial Yeschm, the latter being of the same form,
thickness, and specific gravity as the former.
It is even
asserted, that in Cairo, and other cities, the artificial vases
were as highly valued as those of the real Yeschm, and that
enormous prices were given for them. The Chinese have
also equally well imitated their Ju* stone, which was too costly
for persons of moderate fortune. It is a coloured Glass of
rich appearance, and greenish tint, and of such hardness and
weight, that it frequently surpasses the real Ju. Fragments
of it are often to be met with in the shops of the venders of
curiosities, and some are erroneously denominated rice composition. A square solid pedestal of yellow tinged glass, of Chinese manufacture is preserved in the Museum of Economic
Geology, in London: it is surmounted by a small lion, carved
by the engraver's mandril tool, at the lathe, out of the upper
part of the solid pedestal, at great labour and cost. (See
PLATE 6, fig. 5.) This was, probably, made from English Glass,
re-fused in China with an increased quantity of lead. Small
coloured vases, figures, and almost every description of ornament sculptured in stone, have been imitated in opaque Glass,
by the Chinese. A specimen of artificial Ju stone may be
seen at the British Museum : it is of a bluish-white colour,
resembling enamel, of an octangular form, and about the size
of a snuff-box; it is extremely hard, and, in proportion to its
size, of astonishing weight. Notwithstanding the Chinese pos* Histoire de la Ville, ut ante, p. 159.

ANCIENT MOSAIC GLASS.

17

sess a complete knowledge of the art of Glass-making, the
manufacture of useful articles of Glass appears to be wholly
neglected by them. It is even asserted, that they will not
use the ordinary description of Glass, some of which they
import from Europe; and, when broken, they re-melt, and
convert it into such articles as they require ; they also import
broken flint Glass from Europe, for re-manufacture. The
Emperor has a royal Glass manufactory in Pekin, which is
carried on as much for amusement as for utility.
A most singular art of forming pictures with coloured Glass
was practised by the ancients. It consisted in laying together
fibres of Glass of various colours, fitted to each other with the
utmost exactness, so that a section across the fibres represented
the object to be painted ; and was then cemented by fusion into
a homogeneous, solid mass. In some specimens of this art
which were discovered about the middle of the last century, the
picture has on both sides a granular appearance, and seems
to have been formed in the manner of Mosaic work; but the
pieces have been so accurately united by intense heat, that,
not even by means of a powerful magnifying Glass can the
junctures be discovered. One small fragment, in the possession of Mr. Doubleday, at the British Museum, exhibits an
arabesque border of various colours, the outlines of which are
well decided, and sharp, and the colours pure and vivid; whilst,
a brilliant effect has been obtained in another piece by the artist,
employing in contrast, opaque and transparent Glasses. The
pictures appear to be continued throughout the whole thickness of the specimen, as the reverses correspond in the
minutest points to the face; so that, were the Glass to be cut
transversely, the same arabesque border would be found
D

18

CURIOSITIES OF

GLA£S-MAKING.

exhibited on every section. It is conjectured that this curious
process was the first attempt of the ancients to preserve colours
by fusing them into the internal part of the Glass. (See PLATE
3, figs. 6, 7, 8.)
In the British Museum are many of these interesting
curiosities of Glass Mosaic work, some of perfectly white
clear Glass in the form of leaves or flowers, interwoven in the
midst of a dark green ground; the refraction of the latter upon
the white edges of the flower pattern, producing an intermediate, blended eiFect. Most of the pieces are small, and
some of the patterns very minute; but great study of effect,
and much taste as well as skill, are apparent in their execution. There are also numbers of fragments of white enamel
upon blue, and white upon amethyst grounds, of well executed
designs in relief; probably, executed by eminent Eoman
or Grecian artists resident in Kome. (See PLATE 3, fig. 10) On
precious stones becoming rare or expensive, artists had recourse to artificial gems; some of them were prepared with
two or three layers of colours in opaque Glass welded to each
other, of oval or round forms, to imitate real stones; and these
crude pieces, when worked and ornamented by the lathe,
enabled the gem engravers to meet the public demand at a
comparatively small cost. Artists having thus become accustomed to work Glass in the manner of cameos, the execution of larger objects of taste—viz., vases like the Naples, and
Portland—was comparatively easy.* (See PLATE 1.) A great
* Mrs. Eichardson Auldjo has a fragment of a vase of Etruscan form, with
carved handle and engraved bas-relief ornaments; the remainder of the
fragments are in the British Museum. Minutelli has given a drawing of
the entire vase; the foliage and bird engraving is in white enamel, upon a
blue sapphire ground. This fragment was found in Pompeii, a few years since.

THE PORTLAND VASE.

19

variety of phials and bottles, chiefly of an elongated shape,
have been found among the subterranean ruins of Herculaneum. Most of these are of Glass of unequal thickness,
of a green colour. A few vessels of cut white Glass have also
been found, but they are of small dimensions.
In the British Museum, also, are a few large cinerary urns of
green Glass, which are fine specimens of the ancient art of
Glass-blowing. The round vases are of elegant forms, with
covers and two double handles, the formation of which must
convince any person capable of appreciating the difficulties
which even the modern Glass-maker would have to surmount
in executing similar handles, that the ancients were well
acquainted with the art of making round Glass vessels.* {See
PLATE 5, Hig. 4.) Although their knowledge appears to have
been extremely limited as respects the manufacture of square
vessels, and more particularly oval, octagon, or pentagon forms,
we meet with several crudely formed square vases, a great
number of lachrymatories, and various fragments of other
vessels, some of which have a raised border, hollowed inside,
as if blown in open-and-shut metal moulds: there are, besides,
small blue vases of very rich colours, variegated by yellowish
white enamel patterns, &c.
The most celebrated ancient Glass vase is that which was,
for more than two centuries, the principal ornament of the Barberini palace, and which is now known as the " Portland Vase/'
* An elegant double-handled vase of light green Glass, nine inches high,
and five inches in diameter, exhumed from Bourne Park, near Canterbury,
no doubt of Roman or earlier manufacture, is described in the Journal of
the British Archaeological Association, No. 9, page 48. The handles show
considerable manipulating skill.

20

CURIOSITIES OF GLASS-MAKING.

It was found about the middle of the sixteenth century, enclosed
in a marble sarcophagus, within a sepulchral chamber under
the Monte del Grano, two miles and a half from Borne, on the
road to Frascati. It is ornamented with white opaque figures
in bas-relief, upon a dark blue transparent ground. The
subject has not hitherto received a satisfactory elucidation;
the design,, and more especially the execution, are truly
admirable. The whole of the blue ground, or at least the
part below the upper welding of the handle, was originally
covered with white enamel, out of which the figures have
been sculptured, in the style of a cameo, with astonishing skill
and labour.*- Although there cannot exist any doubt as to the
materials of which this vase is composed, it is extraordinary
that notwithstanding four authors have agreed in considering it
to be stone, all differ as to the kind of stone; Breval regarded
it ascalcedony; Bartoli, sardonyx; CountTetzi, amethyst; and
De la Chausse, agate. That travellers or authors should have
been so ignorant, as to suppose that a natural production
could have been hollowed out of the size of the Portland
Vase seems surpassing strange; nor does it appear less perplexing that each account should differ in the colour and
description of stone. The subject of the bas-relief is
involved in equal mystery, for as much difference of opinion
exists respecting it as of the materials. The fable of Thaddeus
and Theseus was considered by some writers to be the subject;
Bartoli supposed the group to represent Proserpine and Pluto;
Count Tetzi, that it had reference to the birth of Alexander
Severus, in whose supposed tomb it was discovered; while
* Fragments of high art in engraving have been found with as many
as five layers of differently coloured Glasses. (See PLATE 5, fig. 1.)

VENETIAN AND BOHEMIAN GLASS.

21

Mr. Windus, F.S.A., the most recent illustrator, has asserted
the design to be the pictorial representation of a lady of quality
consulting Galen, who at length discovered her sickness to be
that of love for a celebrated rope-dancer. The piece of basrelief engraved Glass, forming the foot, is distinct, and
cemented into the bottom of the vessel; it appears to be of
later date than the body of the vase, and by a different artist;
possibly, an accident in the making or engraving the vase
might have compelled the artist to have the foot of a subsequent manufacture. It has been likewise conjectured that
the neck of the vase being small, the large opening at the
bottom gave more room for putting in ashes or bones,
prior to the foot being finally cemented on. At all events,
this beautiful ancient work of art affords satisfactory proof
that the manufacture of Glass was carried to a state of high
perfection by the ancients.*
Venice, during a long period, excelled all Europe in the
* An account of the Portland Vase was published by the late Mr.
Wedgwood—the Father of the Potteries and an accomplished philosopher :
it is, like its author, truthful and accurate. On this famed Vase being
offered for sale, Wedgwood, considering that many persons to whom the
original was unattainable, might be willing to pay a handsome price for a
good imitation of it, endeavoured to purchase it, and for some time
continued to offer an advance upon each bidding of the Duchess of Portland, until at length, his motive being ascertained, he was offered the loan
of the vase on condition of withdrawing his opposition. Consequently,
the Duchess became the purchaser at the price of eighteen hundred guineas.
I t is stated, that a limited number of copies were sold at fifty guineas each,
and that the model cost five hundred guineas: probably, the celebrated
Flaxman was the artist who was so liberally rewarded. Sir Joseph Banks
and Sir Joshua Reynolds bore testimony to the excellent execution of
these copies, which were chased by a steel rifle, after the bas relief had
been wholly or partially fired.

22

CURIOSITIES OF GLASS-MAKING.

fineness of its Glass. Judging from the curious specimens to
be seen in this country, the Venetian Glass-blowers must have
been artists of considerable skill. A Glass knife-handle,
supposed to be their work, has an exterior coating of white
transparent Glass, enclosing differently coloured Glass, fused
into one variegated mass. The effect of these colours under
the white Glass is very pleasing. The Venetian ball is a
similar specimen of ingenuity. The exterior coating of white
Glass is, in some specimens, much decomposed and defaced
by time; but the beauty of the interior workmanship is easily
restored by the usual mode of polishing Glass. {See PLATE
6, fig. 1.)
The Bohemians were formerly very celebrated for their
extensive Glass-works. They imitated the Venetians in their
curious method of ornamenting Glass-ware, which has since
become well known, and was at one time much in repute in
this country. In making the stems of wine-glasses and goblets,
they enclosed white and coloured enamel tubes, twisted together with colourless transparent Glass. A most beautifully
engraved vase by a Bohemian artist, is in the possession
of the author; the workmanship is even more elaborate
than that of the Portland Vase: the subject is from Le
Brun's painting of the conquest and final overthrow of
the Persians at the battle of Arbela, by Alexander the
Great. For depth of workmanship and artistic execution, as
a modern intaglio engraving, this vase is unrivalled.
In Howel's Familiar Letters we find some curious details
of Venice, and her Glass-making celebrity. The first Letter,
containing these records, is dated, " Venice, May 30, 1621,"
and states: ie Among other little gentile ilands which attend

" VENICE G L A S S . "

23

the cittie of Venice, ther is one called Murano, about the
distance of a little mile, where crystall Glasses are made; and
'tis a rare sight to see a whole street where on the one side
there are about twenty furnaces at work perpetually, both
day and night. It hath bin observed and tryed, that if one
shoed remove a furnace from Murano to Venice herself,—
nay, to the other side of the street,—and use the same men,
materialls, and fuell, and the same kind of furnace, ev'ry way,
yet one cannot be able to make cristall Glasse in the same
perfection, for bewty and lustre, as they do at Murano; and
the cause they alledg is the qualitie and cleerness of the circumambient air which hangs ore the place, and favoureth the
manufacture, which air is purified and attenuated by the concurrent heats of so many furnaces together, which never
extinguish, but are like the vestal fyres that allwayes burn."
In another Letter, dated " Venice, the 1st of June, 1621,"
we find : " The art of Glasse-making is very highly valued in
Venice; for whosoever comes to be a master of that profession is reputed a gentleman ipsa arte, for the art's sake:
and it is not without reason, it being a rare kind of knowledge and chymistry to transmute the dull bodies of dust and
sand, for they are the only main ingredients, to such a
diaphanous, pellucid, dainty body, as we see cristall Glasse is,
which hath this property above gold and silver, or any other
mineral to endure no poyson. Glasse allso hath this rare
qualitie, that it never loseth anything of its first substance
and weight, though us'd never so frequently and so long. It
is wonderfull to see what diversitie of shapes and strange
formes those curious artists will make in Glasse, as I saw a
complete gallie, with all her masts, sayles, cables, tackling,

24

CURIOSITIES OF GLASS-MAKING.

prow, poope, forecastle, anchors, with thee long-boat, all
made out in cristall Glasse, as allso a man in armor/'
Thus, we see that a whole street of Glass-houses was then
in existence, and in full reputation and employment. Much
mystery was, however, current, either suggested by policy, narrow-minded selfishness, or superstition, as to the cause of the
excellence of the Venetian Glass, which by Howel was ridiculously attributed to " Venice air." Its white Glass may,
then, have been appreciated ; but it is far inferior in pellucid
refractibility to modern English crystal Glass. The finest
pieces of ancient Venetian Glass-ware are rather celebrated
for lightness than crystalline beauty; it is excellent, considering that lead forms no part of its composition.
Venice Glass was, however, in high repute in England in
Howel's. time ; for, in another of his Letters, dated " Westminster, 15 Jan., 1635," we find tbe author thus writing
" to Mr. T. Lucy, in Venice :" " My Lady Miller commends her
kindly unto you, and she desires you to send her a compleat
cupboard of the best crystall Glasses Murano can afford, by the
next shipping." Drinking Glasses made at Venice were also
about this time believed, by credulous persons, to have the
property of breaking when a poisonous liquid was poured
into them—an absurd belief referable to exaggeration of the
celebrity of the manufacture. This alleged detective property
is thus referred to by Sir Thomas Browne, in his work on
Vulgar Errors: " Though it be said that poison will break a
Venice glass, yet have we not met any of that nature."
The Venetians, also, originated the modern style of Glassengraving which afterwards extended through all the Glassmaking countries in Europe. The first specimen was scratched

VENETIAN

GLASS.

25

with a diamond, or broken steel file; but the engravings produced by copper and lead wheels at the lathe are far superior.
With few exceptions, the design was a roughed surface intaglio,
which, contrasted with its white transparent ground, had a lacelike delicacy of effect; especially if improved by traced polished
lines, occasionally introduced, to give the relief of light and
shade. The Venetians not only revived the curious ancient
art of forming Mosaic Glass pictures, but introduced many
other ingenious novelties. In the present day, Venice is
unrivalled for its cheap and excellent Glass bugles and beads,
of which enormous quantities are sold for the African and
other foreign markets.
The Venetians and Bohemians had cylindrical drinking
Glasses curiously painted in vitrified colours, with coats of arms,
called vidre come. The ancient painted Glass vase, commemorated in the old ballad of the " Luck of Muncaster," was, probably, of early Bohemian manufacture.* It has also been the
subject of a poetic romance.
In addition to their ordinary window and other Glasses, the
Venetians were celebrated for the following ingenious Glasses>
which, with the exception of the vitro di trino and frosted, were
imitations of the ancient manufacture. (PLATE 4, figs. 1, 2.)
The filigree, which consists of spirally-twisted white and
coloured enamel Glasses, cased in transparent Glass, was
much used by the Venetians for the stems of wine-glasses,
goblets, &c.; and, when placed together, side by side, in
alternate colours, it was manufactured into tazzas, vases, and
other ornamental articles. Millefiore Glass consists of a great
* The different Glass-works of Bohemia are stated, at this day, to afford
subsistence to more than 30,000 persons.
E

26

CURIOSITIES OF GLASS-MAKING.

variety of ends of fancy-coloured tubes, cut sectionally, at
right angles with the filigree cone, to form small lozenges or
tablets; and these,whenplaced side by side, and massed together
by transparent Glass, have the appearance of an innumerable
series of flowers or rosettes, for ornamental vases, tazzas, &c.
(See PLATE 6, fig. 2.) Mosaic Glass, as manufactured by the
Komans and Venetians, was produced by threads or small canes
of variously coloured opaque or transparent Glass, of uniform
lengths, ranged sectionally together in large masses, or in
small quantities, so that the ends shall form grounds, on
which are patterns of flowers, arabesques, or any Mosaic
designs; and these being cut transversely, obtusely, or at right
angles, form slabs of any required number and thickness,
the same pattern being repeated at every cutting. Smetz
Glass is produced by fused lumps of coloured Glass, rolled
one colour into another, so as to imitate cornelian and other
stones. Vitro di trino is fine lace-work, with intersecting
lines of white enamel or transparent Glass, forming a series of
diamond-shaped sections; the centre of each has an air-bubble
of uniform size, executed almost with the precision of engine
lathe-turning. The frosted Glass will be described in a
subsequent part of this work. The Bohemians followed the
Venetians, and imitated most of these curious proceeds of the
Glass furnace.
Glass was first used by the Italians for the purpose of
making cameos and intaglios, by impressing it while warm
into a mould of tripoli; the Glass being sometimes backed
with plaster of Paris. Foreigners visiting Italy are thus
supplied with copies of antique gems for the formation of
cabinet collections. They seldom exceed, however, an inch

THE FrRST ENGLISH GLASS-HOUSES.

.27

in diameter, and perhaps could not be made much larger.
The manufacture of these small artificial gems has been
very successfully carried on by Mr. Tassie, of Leicester-square,
whose collection is extensive and valuable.
The first English Glass-houses for the manufacture of fine
Glass were those of the Savoy and Crutched Friars, established about the middle of the sixteenth century.* It
appears, however, that the English manufactures were for a
considerable time much inferior to the Venetian; for, in
1635, nearly a hundred years later, Sir Robert Mansel
obtained a monopoly for importing the fine Venetian drink ing-glasses. The art of making these vessels was not brought
to {perfection in this country till the reign of William III.
Our Glass-manufacture has since made rapid progress; and
the white crystal Glass-works of England indisputably excel,
at this moment, those of any other country.
The essential and distinguishing qualities of good Glass
are, its freedom from specks or strise, and its near resemblance
to real crystal in its brilliant, pellucid, refractive, and colourless
transparency. In all these respects, the productions of the
British Glass-houses are at present unrivalled. It only remained
* " The Friars' Hall was converted into a Glass-house for making
drinking vessels, which, with forty thousand billets of wood, were destroyed
by fire in 1575. (Stow's Survaie, 293.) The manufacture was set up in
1557, and was the first of the kind known in England. I may add here,
that the finest flint Glass was first made at the Savoy; and the first plates
for looking-glasses and coach-windows, in 1673, at Lambeth, under the
patronage of George Villiers, Duke of Buckingham."—Pennant's " London" 5th edit., p. 377.
Probably these works, either by the use of wood fuel, or some other
cause, were not remunerative; and therefore were not rebuilt at the
Savoy, or elsewhere.

28

CURIOSITIES OF GLASS-MAKING.

for them to evince their superiority in the ornamental branches
of the art; and this has been partially accomplished by the
improved taste of the public, compelling manufacturers to
employ superior artists ; as well as by the encouragement given
by Government in establishing Schools of Design for instruction in classic design and correct drawing.
The ancients were not altogether ignorant of the art of
embodying ornament in the interior of Glass; but their
productions were only partially enclosed. The picture of a duck,
described by Winckelmann, or the arabesque Mosaic in the
British Museum, is but a partial incrustation; as the painting is
neither completely enclosed, nor protected from the air. The
Venetian ball and the Bohemian ornamental stems are perfect incrustations; but they are curious, rather than tastefully
designed, or useful. It was impossible to introduce into the interior of Glass any device or figure, which could be with certainty accurately defined; because, the variegated Glass in the
interior being of the same nature as the enamel, is (especially
if opaque) fusible at a less degree of heat than the coating of
white transparent Glass : consequently, any impression must
have been effaced, when, in the process of manufacture, it became incased in the hot transparent Glass. To render the
art of incrustation subservient to any useful purpose, it was
requisite, in the first instance, to discover a substance capable
of uniting with Glass, but requiring a stronger heat than its
transparent enclosure to render it fusible.
About forty years since, a Bohemian manufacturer first attempted to incrust in Glass, small figures of greyish clay.
The experiments which he made, were in but few instances
successful, in consequence of the clay not being adapted to

THE PATENT CRYSTALLO-CERAMTE.

29

combine completely with the Glass. It was, however, from
the Bohemian that the idea was caught by some French manufacturers, who, after having expended a considerable sum in
the attempt, at length succeeded in incrusting several medallions of Buonaparte, which were sold at an enormous price.
From the extreme difficulty of making these medallions, and
from their almost invariably breaking while under the operation of cutting, very few were finished; and the manufacture
was upon the point of being abandoned, when it was fortunately taken up by a French gentleman, Monsieur de St.
Amans, who, with a perseverance not less honourable to himself than in its results advantageous to the arts, prosecuted
a series of experiments, by which, in a few years, he very
considerably improved the invention. The French have, however, not succeeded in introducing incrustation into articles
of any size, such as decanters, jugs, or plates; but have contented themselves with ornamenting smelling-bottles, and small
trinkets. Nor had the invention been applied to heraldry, or
any other purpose, antecedently to the recent improvements
upon the art in this country.
England has long been famed for bringing to perfection,
and directing to useful application, the crude inventions of
other countries. A patent was, some years since, taken out
by the author of this work for ornamental incrustations, called
" Orystallo-Ceramie," which excited considerable notice at the
time. By this process, ornaments of any description—arms,
ciphers, portraits, and landscapes of any variety of colour—
are enclosed within the Glass, so as to become chemically
imperishable. The substance of which these ornaments are
composed, is less fusible than Glass; it is incapable of gene-

30

CURIOSITIES OF GLASS-MAKING.

rating air, and at the same time is susceptible of contraction
or expansion, as, in the course of manufacture, the Glass becomes hot or cold. It may previously be formed into any
device or figure, by either moulding or modelling; and may
be painted with metallic colours, which are fixed by exposure
to a melting heat. These ornaments are introduced within
the body of the Glass while the latter is hot, by which means
the air is effectually excluded ; the incrustation being thus
actually incorporated in the Glass. In this way, every description of ornamental Glass-ware has been decorated with embossed, white, or coloured arms, or crests. Specimens of these
incrustations have been exhibited not only in decanters and
wine-glasses, but in lamps, girandoles, chimney ornaments,
plates, and smelling-bottles. Busts and statues, on a small
scale, caryatides to support lamps or clocks, and masks, after
the antique, have also been introduced with admirable effect.
The composition used in the patent incrustations is of a white
silvery appearance, which has a superb effect when inclosed
in richly-cut Glass". Miniature landscapes, &c, have been
enamelled upon it, without the colours losing any of their
brilliancy; and thus, instead of being painted on the surface
of the crystal, there are ornaments embodied in it.
A most important advantage to be derived from this elegant invention is the preservation of inscriptions. Casts of
medals and coins do not afford security for perpetuating
them; but, the inscription, when once incrustecl in a solid
block of crystal, like the fly in amber, will effectually resist
for ages the destructive action of the atmosphere. Had this
art been known to the ancients, it would have perpetuated to
us many interesting memorials. In laying the foundation of

PRESSED

GLASS.

31

a public edifice, an incrustation of this kind will be a record
cere perennius.
The late Sir JefFry Wyatville, in laying the
first stone of one of the towers of Windsor Castle, adopted
this mode of recording the event; and other architects of
eminence have placed these incrusted inscriptions in the
foundations of various public and private buildings.
A second patent was subsequently secured by the author,
by which medals, arms, crests, &c, are accurately transferred
from the dies on which they had been chased, to hollow Glassware, especially where numerous repetitions of arms of elaborate workmanship are required. This invention diminishes the
expense of engraving, in transferring the pattern by means
of cakes of tripoli, from the die to services of Glass-ware, and
it has frequently been used with great advantage. It is, indeed, an improvement of Mr. Tassie's mode of accurately
transferring small bas-reliefs or intaglio pictures, from any
material to solid Glass.
The invention of pressing Glass by machinery has been
introduced into England from the United States of America.
It has not, however, realized the anticipations of manufacturers;
for, by the contact of the metal plunger with the Glass, the
latter loses much of the brilliant transparency so admired in cut
Glass; hence, it is now chiefly used for common and cheap
articles. The process of rewarming or fire polishing, after the
pressure, has somewhat remedied this defect. The patent
pillar moulded Glass for articles of table use, is more successful, as it preserves its transparent, pellucid brilliancy. The
interior is smooth, and the exterior having a second gathering
of fused Glass, is expanded by blowing, after it has been impressed by the mould; and by rewarming, technically called fire
polishing, the Glass preserves its refractive brilliancy.

S2

CUKIOSITIES OF

GLASS-MAKING.

Collateral advantages of no small importance have resulted
from these inventions; insomuch as they have tended very
considerably to enhance the value of British Glass-wares, and
to extend the application of Glass to new purposes of domestic
utility. The highly ornamental effect which by this and other
improvements has been given to the manufacture, has recommended Glass incrustations and other ornamental Glass, in the
place of metal ornaments, for door-plates or handles, lamp
pedestals, arms, &c, upon decanters, chandeliers, and articles
of table Glass.
A third patent has been completed for casting from common bottle-glass metal, water or gas-pipes ; but it has not
yet practically worked out those results which will, no doubt,
be attained by more extended experiments and arrangements.
Sky-lights are moulded in strong flint Glass, of embossed
patterns to the segment of a dome, or sphere ;* and strong
panes for windows, or sky-lights, are ornamented with detached
pieces of transparent coloured Glass, massed homogeneously
to white Glass, and having together, a Mosaic and ornamental
appearance; these being included in the last mentioned
patent.
England is pre-eminent for her refractive, colourless, flint
Glass for chandeliers and table articles; and the transparent
metallic colours are of superior quality. With such materials,
when artistic education becomes more extended, the English
Glass-makers will, it is hoped, rival their Continental competitors, in colouring, gilding, and elegant forms.
* Upon this principle, the large cut Glass skylight was executed at the
Falcon G-lass Works, for the ornamental quadrangle of the Reform Clubhouse, in Pall-Mail; from the design of the architect, Mr. Charles
Barry, R.A.

CDonstttuents antr JWanufacture*

GLASS

may be classed into Simple and Compound varieties.

The Simple are, first, Crown Glass, consisting of—
Sand
Ground Chalk
Carbonate of Soda
Sulphate of Soda

5 measures
2
„
1
„
1
„

Secondly, Plate Glass, consisting of—
Lynn Sand washed and burnt .
Carbonate of Soda
Ground Chalk

.

.

400lbs.
250 „
30 „

Thirdly, Common Bottle Glass, composed of
Sand
Soapers' Waste
Gas Lime
Common Clay
Rock Salt

100 measures
80
„
80
„
5
„
3
„

These Glasses, it will be observed, are composed chiefly of
silex and alkali. The Compound Glasses have, in addition to
the above ingredients, more or less metallic substances: for
instance, white enamel has arsenic, tin, or antimony, entering
into its substance, which, as well as lead, form the distinctive
quality of the Compound Glasses, materially increasing their
F

34

CURIOSITIES OF GLASS-MAKING.

specific gravity, and acting as powerful fluxes. The Compound
Glasses are as follow—viz.,
FLINT

GLASS.

Highly pellucid and transparent Flint Glass requires—
Carbonate of Potash
Red Lead or Litharge
Sand washed and burnt
Saltpetre
Oxide of Manganese

1 cwt.
2 cwt.
3 cwt.
141bs. to 28lbs.
4 oz. to 12 oz.

These materials, mixed together, are technically called
batch; and when fused, are termed metal.
Soft White Enamel (Opaque.)—To 6 cwt. of batch, add
24lbs of arsenic, 6lbs. of antimony.
Hard White Enamel (Opaque.)—To 6 cwt. of batch, as
above, add 200 lbs. of putty, prepared from tin and lead.
Blue Transparent Glass.—The above 6 cwt. of batch,
coloured with 2lbs. of oxide of cobalt.
Azure Blue.—The above 6 cwt. of batch, with about 6lbs. of
oxide of copper.
Ruby Red.—The above 6 cwt. of batch, with about 4oz. of
oxide of gold.
Amethyst or Purple.—The above 6 cwt. of batch, with about
201bs. of oxide of manganese.
Common Orange.—To 6 cwt. of batch, add 12lbs. of iron
ore, and 4lbs of manganese.
Emerald Green*—-To 6 cwt. of batch, add 12lbs. of copper
scales, and 12lbs. of iron ore.
Gold Topaz Colour.—The above 6 cwt, of batch with 31bs.
of oxide of uranium.
A beautiful blue may be produced from nickle, but cobalt
is generally preferred; the latter, for casing, should be

F L I N T GLASS.

35

free from impurities. Glass-makers differ in their recipes
for colour, of which there exists a great variety. The above
will be sufficient to give a general idea of the principle of
colouring.
Suitable cullet, or broken glass, may be mixed with the
batch of the above glasses, in quantities at discretion.
The base of all Glasses is sand; and suitable alkali is
the chief solvent. In the Compound Glasses, oxide of lead,
whether in the form of litharge or red lead, as well as the colouring metals, are active fluxes. These Glasses, therefore, require less alkali, in proportion to the sand, than the Simple.
Flint Glass, which ought rather to be termed metallic Glass,
needs, for its fusion, less caloric than plate Glass, or any of the
Simple Glasses. As the Simple Glasses require intense heat,
they are melted in open pots, so that the flame comes at once
in contact with the materials. Flint and the Compound Glasses
must be melted by the heat going through the pot, which requires to be covered, or hooded; or the fumes and smoke of
the coal would carbonize or deoxydize the lead, and precipitate it to the bottom, in its original metallic state. Dried
beech or oak wood is used for fuel in some parts of France
for Flint Glass, with open pots; and so little carbon is produced by the smoke, as not to affect materially the metal,
although the flames play upon its surface. Formerly, flints
were calcined and ground, for Glass-making; but for many
years past, Isle of Wight, Lynn, or Eeigate, sands have been
substituted; these sands are not only more free from iron,
but less expensive in the preparation, than flints when washed
and calcined.
Some manufacturers cleanse sand by hand-washing, and
others have machines: to render the Isle of Wight sand fit for

36

CURIOSITIES OF GLASS-MAKING.

making the Compound Glasses, to cleanse it from chalk and
other impurities, by which it loses about one fifth of its original
bulk, requires about eight waters; it is afterwards passed
through a heated arch, called a calker, and thoroughly dried, or
burnt, at the discretion of the operator; and then sifted through
a lawn sieve, to separate the larger grains and pieces of coal or
coke, and burn off the vegetable matter.
Carbonate of potash, known by the commercial term of
pearlash, is imported from British America, and from Kussia:
it contains, besides carbonate of potash, sulphates and muriates of potash, and other impurities, which will not enter
into the composition of Mint Glass. These may be separated,
by dissolving the potash in warm water; when cold, the impurities finally sink to the bottom of the vessel, and the lye
containing the refined carbonate of potash is drawn off by a
syphon, and evaporated to dryness.
This process is, however, rarely practised, as pure carbonate
of potash is now obtained from the alkaline residuum of nitric
acid—viz., sulphate of potash. Alkali makers at Birmingham
and Liverpool supply Flint Glass-makers with refined pearlash made from residuum or caustic potash, so as to save the
trouble of refining potash on the Glass-maker's premises.
Litharge is usually produced at Newcastle, in furnacing
pig-lead, in order to extract the silver from it. Ked lead
is made also from furnaced pig-lead to obtain oxygen
from the atmosphere; after which it is ground in water,
and dried to an impalpable powder. Litharge has but one
atom of oxygen; red lead has two, or a double dose of
oxygen, and has less power than litharge by about two per
cent, which must be allowed for in the mixing.

OPTICAL GLASS.

37

To the three materials of Flint Glass—viz., sand, red lead,
and carbonate of potash, is added a small quantity of saltpetre,
which increases the dose of oxygen, and assists to drive off the
globules of air in the liquid Glass; there are, also, added to
each pot a few ounces of crystallized manganese, the effects of
which will be described hereafter. The whole is carefully mixed
together, and sifted through a coarse sieve: in this state it is
called batch, or frit, and is of a salmon colour. It is by the
purity of these materials that the British manufacturer is
enabled to maintain ascendancy over the foreigner for pure
metal or Flint Glass; and its superior quality is especially
due to the excellence of the red lead, which imparts density,
refractibility, transparency, and pellucid brilliancy.
If Flint Glass be required of great density for optical
purposes, it is only to add a larger dose of red lead, or
litharge, beyond what might be termed the atomic mixture
of one of alkali, two of lead, and three of sand, (of the specific
gravity of 3*200,) and it will produce Glass of higher density,
but less permanent, in the ratio of its increased specific gravity.
Were the proportion of lead twice the atomic quantity, the
surface of the Glass would be more or less liable to decompose
by exposure to the atmosphere, and need constant wiping to
preserve its transparency; it might even require to be repolished
for the same object, and that repeatedly. Excess of alkali is
equally as injurious as excess of lead, and, indeed, more destructive, through the effects of time and atmospheric influence, as
will be more fully explained in a subsequent part of this work.
Crystallized black oxide of manganese is best fitted for a Glassmaker's purpose, if well washed from aluminous earth, with
which it is ordinarily found combined in mines. The most

38

C U R I O S I T I E S OF GLASS-MAKING.

permanent Flint Glass is that which by the greatest caloric can
be made to contain the largest proportion of silex; but it is not
so well calculated for chandeliers, (which should be more
highly refractive,) nor for optical purposes, as for ordinary
uses.
Flint Glass is remarkably elastic: it may be spun so thin as
to bend nearly double without fracture; by the aid of slight heat,
it may be curled into ringlets to represent human hair, or it
may be blown so thin as nearly to float in the atmosphere; and
it has been woven with silk and other substances by Messrs.
Williams and Sowerby's Patent Process, so beautifully as to
give the brilliant effects of silver and gold, in colours superior
to the precious metals themselves.* Hollow Glass balls are so
elastic that if dropped from a height of ten or twelve feet upon
a solid polished anvil, they will rebound from half to threefourths of that height, and generally without fracture, until
after the second rebound.
Flint Glass, of not less than the usual density of 3*200,
well polished by the lapidary, is considered the nearest approach to the diamond.
Glass is admitted to be one of the most useful and beautiful
of materials in ornamental and industrial art. Chemistry and
astronomy could scarcely exist without it. The delicacy and
accuracy of the chronometer require its aid; while the common
green bottle Glass can be manufactured cheap enough for casting conduit pipes, for chemical uses, or the supply of the
metropolis with pure water. No chemical test is so delicate
* It is not within our province to describe the constituents of arsenic,
oxide of tin, or the colouring oxides, which will be found detailed in
treatises on chemistry.

T H E WORKING

CRISIS.

39

as a mass of fused Mint Glass: it will detect the presence of
metallic colouring matter, especially iron, although the most
carefully conducted analysis may fail in discovering the slightest
trace of it. Mr. Josiah Wedgwood found that S^OTO P arfc °%
gold would give a rose-coloured tint to Flint Glass. With the
best possible recipe, and the purest materials, good results
depend upon an intense and continuous fusion: too little
caloric will fail to refine it, and drive off air-bubbles,
and the colouring matter of the manganese ; and too long
continuance of intense heat will destroy the manganese,
cause the Glass to attack the pot, and become striated, gelatinous, and greenish. Extra time, at a lower rate of temperature, will not make up for want of continuous intensity. The
most intense heat can scarcely be considered too great; but
the moment the metal is fully fused, and refined by continuous
rapid fusion, the high temperature of the furnace should
be reduced from its maximum heat to a working temperature:
this period being considered the crisis. Achromatic plate
should be made while the metal is in this quiescent state:
it is then most free from striee; but, should intense heat be
subsequently renewed, it tends to reproduce them. There is,
therefore, a period of comparative perfection and purity, at
which, if Mint Glass be not worked for optic use, the opportunity is for ever lost.
When Flint Glass is kept in fusion beyond the crisis, it not
only assumes a greenish tint, by acting upon the iron of the
Stourbridge clay pot, but takes up a small portion of its
alumina; which, by its inferior density, rises to the surface,
frequently with detached portions of the pot, causing strise,
and other impurities, which render it entirely unfit for optical
purposes.

40

CURIOSITIES OF GLASS-MAKING.

Although annealed glass will break with the greatest facility
by unequal pressure (or vibration of the particles from a centre),
yet it is found to withstand uniform or equable internal pressure greater than either of the metals.
The property of welding by contact at about a red heat is
peculiar to Glass, whether with or without lead. But for
this useful fact in the ornamental department of Flint Glass,
as regards the addition of handles, feet, rings, &c, the
manufacturer would be left without those manipulatory decorations of his art. So perfect are the weldings, that at th§.
points of union they become as completely one homogeneous
mass as if the whole were gathered in one piece; yet,
the slightest sulphurous or carbonaceous film intervening
between the parts required to be welded, will cause the cohesion utterly to fail.
Another peculiarity, of which the manufacturer avails himself,
is the liability of Glass to fracture instantaneously by contact
with a cold metal, or by any sudden chill; this causes instant
contraction of the part affected, which cracks through the mass
by a slight blow, as perfectly as if cut with a diamond. Welding by contact, and separation by contraction, are therefore
two principles, without which the manipulations of the Glassblower would be comparatively inoperative.
Having disposed of a few of the peculiarities and eccentricities of Glass, we proceed to give some account of its manipulatory conditions. One of these depends upon a constant rotary motion being given by the workmen to the Glass
gathered upon a hollow blowing-iron, which will, when done
with judgment, not only prevent the Glass from falling from
its position, but if rapidly rotated, will increase its diameter
on the principle of centrifugal force. If a depressed form

OPTIC FLINT PLATE.

41

be required, the blowing-iron must be held perpendicularly,
(with the Glass at the top of it,) so that the shape may
be depressed partly by its own gravity, and partly by rapid
rotation. Should the Glass vessel be required of an elongated
form, the blowing end of the iron must be held uppermost,
the Glass downward, and oscillated like a pendulum, or
swung rapidly round vertically, thus, again uniting the principle of gravitation to that of centrifugal force.
Before describing the manipulations of moulding Glass or
making it by hand, a short account of experiments upon
Optic Flint plate may be interesting. For many years subsequent to the time of the celebrated Dollond, English Flint
Glass was almost the only heavy Glass used for telescopes,
both at home and on the continent. It was generally made
from the usual mixture of Flint Glass, with about ten per cent,
increase of lead; but still more often of the ordinary mixture
(of lead and other materials), and of the specific gravity of
about 3-250 to 3-350. The process is as follows :—A ladle,
in the form of a sugar-loaf, about five inches in diameter and
seven inches deep, is clipped carefully into the metal, which
has been previously skimmed; when filled, it is taken out
of the pot, and suffered to get partially cool; to the large end
of the sugar-loaf shaped piece of Glass thus produced, a Glassblowing iron with a hollow disk is welded, and placed to the
opening, or mouth of the pot for re-heating; when sufficiently
soft, it is blown into a muff, as hereafter described, and
illustrated, under the head of the Cylindrical Lamp Glass:
the end furthest from the blowing-iron is cut off, the cylinder is flattened into pieces or plates of fourteen inches long,
ten inches wide, and of about half an inch thick, and anG

42

CURIOSITIES OF GLASS-MAKING.

nealed; in which state, the plates are sold to the optician, for
cutting and grinding into disks
Since the time of Guinand, of Brenette, in Switzerland, and of
Frauenhofer, and others who have done good service to science
by their meritorious labours and improvements, the opticians
of England have imported many large sized achromatic Glasses
from the Continent; although the British manufacturer, (who
only occasionally makes for home use,) still supplies eminent
foreign workers with Glass for optical purposes, some of which,
no doubt, finds its way back into England, as foreign, at a very
advanced price. Guinand's plan has already been published :
the secret of his success is considered not to have been in the
novelty of the materials or proportions, but in agitating the
liquid Glass while at the highest point of fusion, then cooling
down the entire contents of the pot in a mass, and, when
annealed and cool, by cleavage separating unstriated portions,
afterwards softening into clay moulds. Dr. Faraday is of opinion
that the usual materials of British Flint Glass are excellent;
and that the necessary improvement is chiefly mechanical,
and not chemical. As a proof, the very heavy Glass he has
produced owes its freedom from striee to his plan of constant
agitation, as detailed in a paper communicated to the Koyal
Society, in the year 1829. M. Bontemps, a scientific French
Glass-maker, has succeeded in making good Flint optical
Glass also on the principle of mechanical agitation; and was
rewarded for his process by the French Society of Arts, in 1840.
In the year 1845, he published the result of his experiments.
M. Bontemps operated in conjunction with one of the sons of
Guinand as follows. A long hollow cylinder or sheath of fire-clay
closed at one end, with a bore sufficiently large to admit of a
strong blowing-iron, was brought to a red heat, and introduced

IMPROVEMENTS BY BONTEMPS.

43

into a pot of melted Glass. This agitating iron had along
handle with a flat ring, or hand-guard, which rested while in
use upon the shoulders of the pot: it was then introduced into
the fire-clay cylinder, or sheath, and when the metal was at its
utmost intensity of fusion, the mixing began, and continued
for many hoars, until the operator presumed the striae were
dissipated ; then, by gradually reducing the heat of the furnace,
the Glass became too stiff for agitation, and the pot, and its
contents, were annealed in the furnace. Crown Glass will
not allow of so many hours' intense fusion and agitation as
Flint Glass, owing to its liability to devitrify. M. Bontemps does
not assert that he always succeeded in the stirring system, for
Flint Glass. He sometimes found hard masses of small
cords, as it were, felted together : these he thought were caused
by the chemical action of the Glass upon the fire-clay cylinder
and pot; but they spread in the operation of cooling. His
plan of cleaving pieces from the blocks of Glass, and softening
the disks in moulds, was similar to that of M. Frauenhofer. He
suggested an iron agitator cased in platinum as a practical improvement, which the author of this work thinks is chemically
objectionable. He also recommended that an entire pot of flint
metal, fused upon the agitation system, should be emptied
upon an iron table, and cast the same as Plate Glass. Mr.
Dollond has used this kind of French Glass with partial success, although it has not generally been sufficiently annealed.
M. Bontemps's proportions are as follow:
For Flint Glass—
Sand
Red Lead
Carbonate of Potash
Nitrate of Potash

43-5
435
10
3
100

44

CURIOSITIES OF GLASS-MAKING.

For Crown Glass—
Sand
Carbonate of Soda .
Carbonate of Lime
Arsenic . . . .

60
25
14
1
100

On examining the records of these practical modes of obtaining the best achromatic Flint Glass, it will be found that our
philosophic countryman, Dr. Faraday, (the plan of Guinand
being then a secret,) suggested the same idea of stirring, which
was carried out successfully in the heavy Glass he manufactured. This was composed of—
104 Protoxide of Lead.
24 Silicate of Lead.
25 D r y Boracic Acid.

His Glass required but a red heat for fusion, thereby offering
facilities for minute agitating operations. Although it is not calculated for permanence or general use, its manufacture developed
the fact, that the destruction of striae is more dependent upon
mechanical than chemical appliances; and that Dr. Faraday's
conclusions and those of MM. Bontemps and Guinand, jun., were
identical in principle. The question may be asked, Why should
there be difficulty in obtaining good achromatic flint Glass ?
There would be none, (is the reply,) if a manufacturer could
anticipate a fair remunerative price and demand, after having
succeeded in obtaining the quality. Probably, he could only sell
600 cwt. per annum, even were he to supply all the opticians
in Great Britain at ten times the price of ordinary Flint Glass,
which would scarcely be remunerative, whether he manufactured in one of the pots of a ten-pot furnace, containing
each fifteen or eighteen cwt.; or upon a smaller scale, in

FLINT GLASS WORKS.

45

a furnace of one or two pots not exceeding fifty pounds each,
kept working for that sole purpose. In the ordinary course of
Flint Glass manufacture, working a large pot of Glass for optical purposes not only retards general operations, but usually
spoils the greatest part of its contents, whilst the quantity
of optic plate produced is comparatively small, and uncertain in its results; and if unfit for the optician, it becomes
valueless to the manufacturer for other purposes. As an
affair of science and merit, especially were a Government
premium offered for an uniformly certain process, which has
not yet been accomplished at home or abroad, it is anticipated
that English manufacturers would rival foreigners in this field
of honourable competition. The author has constructed a small
furnace, to try the principle of agitating fused Flint Glass by a
rotating pot, with one or more interior divisions: and this
means of subjecting the Glass to an uniform intensity of caloric
and agitation in a covered pot destroys the striae or cords by
mechanical means, without exposing the contents to the cooling effects of the atmospheric air.
Flint Glass works require a very considerable area of ground
—viz., about half an acre or more—to conduct the various operations; and separate apartments are requisite for
washing sand, refining alkali, and picking and washing
broken glass, technically called cullet; besides mixing-rooms,
&c, there are, likewise, requisite one or two furnaces, usually
with ten melting pots in each; a horse or steam mill, for
grinding old crucibles or pots; from two to four arches,
with their fire-places, for annealing Glass; and large rooms,
or lofts, in which to mix clay for making pots and crucibles; besides store-rooms and a packing warehouse. The whole should
be so planned, that the crude materials in the course of pre-

46

CURIOSITIES OF GLASS-MAKING.

paration and mixing are always moving upwards to the fusing
furnace; and when manufactured, they are placed in the
lears, and drawn downward by machinery towards the warehouse, packing-rooms, or cutting-shop; which arrangements
prevent breakage, and unnecessary moving of tons of materials. Besides the above, are a steam-engine, shafts, lathes,
and tools in the cutting-shop, stoppering lathes, &c.; so that
the whole of the processes may be conducted on the same premises. A furnace for burning the sand, another for getting
up the pots to the requisite white heat, preparatory to placing
them in the fusing furnace, also form part of the establishment.
The erections, with fixtures and implements, for two tenpot furnaces, capable of melting in each, per week, about
12,000 or 15,000 lbs. weight, (from which can be manufactured
weekly into wares about 6000 lbs.,) will cost from 1.2,000/.
to 15,000/., besides the expense of the ground. Thus, extensive
Flint Glass works in good situations may be estimated to cost
about 20,000/.: they will be capable of making weekly about
12,000lbs. weight of manufactured goods, half of which will have
to be cut or stoppered; and the total annual returns at wholesale prices may be estimated at about 25,000/. With the exception of the pot-rooms and cutting-shops, all the processes of a
Glass manufactory are conducted on the ground-floor, as it
would incur great loss of labour to move heavy masses of
material into upper rooms.
The management of Glass-houses in France and in England is uniform in the respective countries; but differs from
each other very materially.
The French, work and fill continuously—that is, the whole of
the workmen gather simultaneously out of two or three pots :
these, when emptied, are immediately refilled with mate-

FRENCH AND ENGLISH GLASS-HOUSES.

47

rials, twice or oftener in the week; while these are fusing,
the workmen gather out of other pots, so that all the pots
are consecutively worked out twice or thrice weekly. By
this mode, a greater quantity of Glass manufactures can be
produced than by the English management; but the pots must
be comparatively small, the metal will not generally be so well
refined, and the fusion must also be conducted in the shortest
possible time. Large quantity and low price being the chief
desiderata, the men work the entire week at weekly wages,
(except during twelve hours on the Sunday), which is the
most economical method.
English management has been uniformly the same during
the last half century. As the Excise found its system, so, by
its stringent and vexatious regulations, it continued to the termination of its destructive reign; and, although its injurious
shackles are now removed, long habit, the difficulty of getting
workmen to labour during the entire week, and the alteration
of English piece-work to French time-work, (notwithstanding
an increased weekly remuneration would be the result, (would
render it difficult to effect a change. Circumstances and competition may, however, prove the disadvantage of our present
management, at no distant period, and compel home manufacturers to adopt a more economical arrangement.
In a Glass-house in England, the pots are filled but once
a week, usually on Friday or Saturday morning. Wood vessels, like
hand-barrows, are used for bringing to the furnace the mixed materials, which are thrown into
pots, holding about 18 cwt. each,
in

quantities

Of a b o u t

4

CWt. a t

Glass-house Pots.

48

CURIOSITIES OF GLASS-MAKING.

a time, with iron shovels, allowing sufficient time between each
filling, for melting down the various charges, until the pot is
entirely filled with fused Glass. By this method, every pot in
the furnace is fully charged with liquid metal, in about twelve
to fifteen hours; air-bubbles and strise then abound, and they
are not expelled until thirty to forty hours more have elapsed,
during which period—viz., from fifty to sixty hours, the gas
and air-bubbles are driven off, and the mass becomes homogeneous. English melting-pots, being usually much larger
than the French, require a longer period for fusion, thus
increasing the difficulty, if a second filling be required
during the week; but the Glass is not usually so pure as
the first, through less time being allowed for the second fusion.
When all the pots are filled, and the mouths are securely
stoppered and clayed up, the founding commences, during
which thirty to forty hours (as before alluded to) the furnace
is urged to its utmost intensity; no pyrometer is used, as
the heat varies according to the condition of the furnace,
aspect, and intensity of the wind, quality of the fuel, and
attention and tact of the tiseur, attendant, or stoker. Nevertheless, there are certain signs by which a practised eye can
detect the fitness or unfitness of the metal for working : these
are—the whiteness of the flame exuding from the furnace, on
each side of the pot; also by occasionally withdrawing, with
an iron rod, a little of the melted Glass from the top of, the
metal, through a small sight-hole in the stopper, and at fixed
times taking proofs of the metal. Saturday and Sunday are
the days when the furnace requires the greatest heat, so that
the working may be commenced early on Monday morning.
The shorter the time of fusion and refining, the better : for

FUSING AND BLOWING.

49

this purpose, the heat can scarcely be too great: driven snow
is not whiter than the burning coal in the centre of the furnace, when it has reached its maximum of intensity.
If the Glass do not get fine by the usual time allotted, and
it should become coddled or gelatinous, it never will recover,
however urged by subsequent fusion. Such Glass must be
ladled into water, and considered only as cullet for re-fusion,
with a proportion of new materials.
The man who acts as tiseur has a substitute allowed him
every other Sunday. One man only is necessary to attend the
furnace while founding; but a boy, in addition, is desirable,
in case of accident by broken pots, that he may be sent
to procure assistance, should it be necessary; or that he
may, in such cases, suddenly ladle the remaining contents
of a broken pot of Glass into water, to prevent its running
to waste through the bars, and checking the heat of the
furnace.
Formerly, scum, or sandiva, was allowed to run off, or was
taken off the surface of the pots when opened for working, on
Monday mornings ; but the modern relative proportions and
purity of the chemical materials are so good, as seldom to
render this skimming necessary.
The blowing process commences on Monday early, and
ceases on Friday, in the morning, or towards noon, so that
the blowers have part of Friday and the whole of Saturday,
for recreation : still, it is not found that the average health or
longevity of English workmen is superior to the French, who
work throughout the week. Both French and English have
two sets of workmen, day and night, relieving each other
usually every six hours; but in some parts of the Continent,
H

50

CURIOSITIES OF GLASS-MAKING.

the change is only every twelve hours, with suitable time for
refreshment, &c.
The English blower works about forty-eight or fifty-four
hours; and the French, seventy-two hours per week.

GLASS-HOUSE

POTS.

The most important department of Glass-making is the
manufacture of the melting-pots. For this purpose, the best
Stourbridge clay, in the lump, should be selected, and only
that part ground which is free from impurity: this peculiar
fire-clay is usually found in iron districts; the best is from
Stourbridge, in Worcestershire; it may be termed a silicate of
alumine. Too much of the latter would render it too fusible;
and if in excess of silica, it would fail to cement the mass
efficiently, so as to bear the weight of the fluid Glass, viz.,
about eighteen hundred weight. Eather too much alumine
is usually found in this sort of clay, and pots stand better
by having about one-fifth in quantity of old pots ground, and
used with four-fifths of new clay, which mixture retains sufficient tenacity. The ground potsherd not only assists to dry
the pots more regularly, but it renders the whole body more
porous, and less likely to split by sudden heat. Very few
manufacturers use pots made from new material only.
The chamber where the clay is kneaded, and the pots are

MELTING-POTS.

51

built, should be well selected: not too distant from the furnace
pot-arch, of uniform temperature, neither below fifty-five nor
above eighty—above eighty would dry the pots too fast, and
below fifty-five is not desirable, although a temperature as low
as thirty-two would not absolutely injure them. A middle
or ground floor is preferable to an upper floor, which in
summer would be too much exposed to the heat of the sun,
and in winter too cold. The ceiling should be well secured
against particles of plaister dropping into the clay, and the
floor should be well ploughed and tongued, to prevent a substratum of cold air, which in any case is difficult to avoid.
At only four feet from the floor, the upper and lower temperature will often differ as much as ten degrees, to the great
danger of breakage in drying.
Three months may be adequate for drying a pot, but four
or six months are preferable; the large covered pots, similar
to those in the engraving, will contain about eighteen hundred
weight of melted glass : they measure three feet external diameter, and three feet high, to the filling part, and weigh about
ten hundred weight. This description of pot is used for white

of the above dimensions.
Pots for coloured glass.'
Upon the durability of the melting pots, (all other arrangements and management being good,) the profit and success of
the manufacturer chiefly depend. Large melting-pots, with
the cost of coals and attendance to heat them for the furnace,

52

CURIOSITIES OF

GLASS-MAKING.

are estimated to cost 10/. each. The least number generally
required, (with good success,) for a ten-pot furnace, is from
ten to fifteen pots per annum ; but some manufacturers have
set as many as fifty new pots in one year. Not merely is the
expense of the pots to be considered, but the disappointment
in not being able to execute orders that may be pressing, and
the loss of metal running out of the broken or cracked pots
through the furnace; whilst the fixed expenses for fuel and
establishment are the same for the production of a small as
for a large quantity of manufactures. During the Excise
reign, no pot could be moved from the spot where it was
dried, to be placed in the annealing arch, without a notice in
writing to the supervisor; a second notice was required for
gauging; a third for setting it in the furnace, again for filling
the pot, and another for ladling it out; whilst the maker was
forced to comply strictly with the act of parliament, by
giving the officer six hours* notice for each of these intricate
and vexatious requirements.
Foreign melting pots are usually made in wooden moulds,
lined with cloth: if small, this plan answers where a great
number are required; but British manufacturers almost
invariably build their pots without moulds. The old and new
clay being mixed together, and allowed to be saturated fully
with water, the process of kneading by men's feet is repeated
three times over, until the mass has a pasty consistence. It
is then rolled into small pieces, about the size of a sausage;
these wet clay-rolls are placed together (upon a lead slab)
to the thickness of full four inches, to form the bottom,
which is beaten with a wooden mallet, and pressed with
the hand; the sides are raised by pressing the clay sau-

POT-MAKING.

53

sages from the inside of the curve upon preceding rolls,
so as eifectually to exclude the air, leaving the substance of
the sides from two and a-half to three inches thick; the
dome is continued in the same manner, circle upon circle,
roll pressed upon roll, until the roof is completed, each circle
diminishing towards the centre. It is then left, and the air
within becoming somewhat rarefied, supports the dome until
the pot is sufficiently hard to allow of cutting open and
finishing the mouth. Kneading by the naked feet answers
better than kneading by a pug-mill or machinery; the latter
was tried at the Falcon Glass Works on a large scale,
scarcely a single pot out of fifty or sixty was capable of
holding Glass. The weight of the hunian body, the elasticity of treading, and the warmth of the feet, probably expel
the air from the clay, better than machinery.
When the pots are dry, they may be removed to a hot room
of one hundred to one hundred and fifty temperature. Before
setting in the Glass furnace, great care is necessary to anneal a pot in the arch; and a week or more should be
allowed gradually to bring it to a white heat, ready for pot
setting. This work is always performed towards the end of
the week, and is a hot and fatiguing operation; all hands must
be present, and absentees, except from illness, are severely
fined. The men are provided with suitable dresses to shield
them from the ojoen blaze of the furnace. The old pot,
being no longer useful, by age or accident, is then exposed,
by pulling down the temporary brick-work; a large iron bar,
steeled and sharpened at the point, is placed across another
bar, to operate under the pot as a fulcrum; several men
rest their entire weight upon the end of this long lever, and,

54

CURIOSITIES OF GLASS-MAKING.

after one or many efforts, and perhaps many more simultaneous blows of the bar, used as a sort of battering-ram—the
old pot, either wholly or by pieces, is detached from the siege
of the furnace.
About six or eight men take afterwards each a bar about five
feet long, like a javelin steeled and sharpened at one end;
they rush forward in face of the fiery furnace, guarding their
faces with their protected arms, and aim a blow at such of
the irregular rocky incrustations of clay as adhere to the
siege. This operation is repeated until the pieces of partially
vitrified clay are wholly removed from the position on which
the old pot stood, which should be repaired with clay and
sand. The new pot, at a white heat, is then removed from
the annealing pot-arch, and carried upon the end of a twowheeled iron carriage with a long handle, by four or more
workmen, who carefully set it or tilt it backwards into its
proper position in the furnace.
In the interim between removing the old and setting the
new pot, an iron screen is placed before the opening of the
furnace, which, having lost much of its heat, is urged gradually
to its original high temperature. Seldom more than two pots
are set in one week; to do more would endanger the other pots
in the furnace, by their getting too cold, through the furnace
remaining so long open. The fatigue and exhaustion of the
men, who are often detained four hours in this operation, is also
very great, and is attended occasionally by severe falls, burns,
or bruises, by liability to catch cold, great excitement, energetic
exertion, and exposure to the flame of the open furnace. Good
pots will average three months each in the furnace, and some
are known to last above twelve months; in this case, they

POT-MAKING.

55

wear dangerously thin at the back, where, should they suddenly burst, nearly the whole contents would be lost in the
furnace. Glass-makers patch up pots in the crown or in front,
and occasionally at the bottom. A pot split dangerously in
the front is preserved from leakage for several weeks by
exposing the cracked part to the atmospheric air, (first
taking away the temporary brickwork in front,) which chills
and hardens the metal as it exudes, until it is stopped by its
own leakage. Should the temperature of the atmosphere be
insufficient to check the leakage, cold water must be thrown
upon the fissure; or a piece of black Glass or common bottle
metal softened by heat, and plastered upon the opening. A
crack in the bottom may sometimes be prevented from leakage
by lifting the pot and contents by leverage upon fire-bricks,
and exposing the bottom to air or water, as before described;
but the latter seldom answers, although a broken-fronted pot
may last many weeks, and fuse metal moderately well.

Elevation of t h e furnaces, and interior view of t h e Glass-house
and working operations.

FURNACES.

A flint Glass furnace, in principle, is intermediate between
an air furnace and an oven : too much draught would drive
the caloric up the chimney or shaft, and too little would fail
to yield sufficient oxygen to support the requisite heat. The
draught must never be too strong to prevent a plus, or pressure of short and sharp flame outwards from the bye-holes of
the furnace on each side of the pot mouths. Large caves,

DESCRIPTION OF THE FURNACE.

57

extending through the subterranean area of the Glass-house,
connected with the open air at each end, under the bars of the
furnace, receive the fallen cinders, and supply the oxygen
necessary for the combustion of the fuel. At right angles
with the large cave, are smaller caves, communicating so as to
catch the wind from as many aspects as possible.

A
Ground plan of the siege flues a n d fire-place of t h e furnace, w i t h nine
large pots and t h r e e small, i n their respective positions.

The coals are shovelled through the square hole (A), on to
the grate, in the centre of the furnace (B) ; two strong iron
sleepers support the bars, which are prevented from melting,
by being previously covered with a layer of clinkers, potsherds, or broken Welsh lumps; but as the furnace, in process
i

58

CURIOSITIES OF

GLASS-MAKING.

of time, gets to its maximum heat, it usually forms sufficient
clinkers from the coals; the potsherds are then no longer
needed.

Interior view of t h e Stourbridge brick dome.

Dimensions of a furnace for ten pots, of thirty-six inches
diameter—viz., twelve feet seven inches inside diameter of
the siege; nineteen feet outside diameter; including the flues;
four feet six in height to the inside centre of the dome (D),
each of the arches (E), being three feet one inch wide, by three
feet three and a half inches to the highest part.
A Flint Glass furnace is reverberatory : and as no heat or
flame is usually allowed to issue from the centre, it therefore
seeks escapement through the linnet holes (c), below the foot of
the dome, and passes up the flues (F), viz., one between each of
the ten pots placed around the siege, discharging the smoke,
&c, into the outer brick dome, as shown in page 56, and from
thence through the funnel and chimney-shaft. The duration
of a furnace is scarcely ever less than three years, and often
exceeds ten years, according to the quality of the Stourbridge
clay bricks : some of these weigh nearly half a ton; they are

MANAGEMENT OF THE FURNACE.

59

usually made from two parts of ground potsherd, (the glass
being carefully chipped off,) and one part of new clay, kneaded
by the feet, &c. Occasionally, the siege, or bottom of the
furnace, is repaired, and a new crown (E), or the greater part
of the crown, renewed, without extinguishing the furnace.
In case of accident, which is not unfrequent, as the falling
in of part of the arch, or crown of the furnace, the tiseur must
throw upon the bars as much fuel as possible from the teazehole, and then, through the breach in the crown, fill the
entire furnace with a solid mass of coals and cinders; the upper
part of which forms a centre upon which to build anew crown,
or arch. The draught is thus almost stopped, and but little consumption of coal takes place, while the workmen are proceeding with the new arch, under the inconvenience of the smoke
and heat of the furnace. The pots remain partly or wholly
full of metal. When this is completed, the furnace is gradually urged to a maximum of heat, and the debris is taken
out by degrees into the cave beneath, by removing a bar
or two. In the course of twelve hours, by means of prepared arch-bricks, and Stourbridge clay as mortar or cement,
the repair of a fearful accident in the midst of the blowing operations has been completed by the workmen ; and that
without materially, if at all, diminishing the weight of the
week's work of manufactured Glass.
Eound furnaces are most economical, and almost exclusively used for Flint Glass works. Economy of fuel greatly
depends upon the size and proportions of the furnace: too
large dimensions leave too great an area unoccupied by the
pots or the fuel; and too small a furnace exposes the backs of
the pots, (which are placed round the exterior diameter of the

60

CURIOSITIES OF GLASS-MAKING.

furnace,) to hang over the fire-place in the centre; this in
time enlarges by burning away, and causes them to crack at
the bottom or back, by cold draughts through the fire-bars, if
holes are too suddenly opened beneath by the tiseur, for the
admission of air to urge the heat of the furnace after potsetting. Occasionally, too, when the centre part of the siege
has been partly destroyed by the flame, a pot full of liquid
Glass has been known to fall back into the fire-place, or grate;.
and, as the intense heat prevents any means of raising
it again to its erect position, with iron boat-hooks, which become straightened by the melting heat of the furnace, the back
of the pot must of necessity be tapped with an iron bar through
the grating below, and the whole contents allowed to run
into the arch beneath the furnace. The author has been present
on such an occasion, and finds it difficult to describe the
awful beauty of the prismatic colours of the liquid fire, as it
showered into the cave.
Ten pots of thirty-six inches diameter are the medium
number for a well proportioned furnace, and are found the
most economical for fuel.
The crown of the furnace should be as low as can be built,
to support itself, and to admit the pots, that the fuel may not
be wasted by heating a useless interior area.
The consumption of fuel by a well constructed ten-pot furnace will be from eighteen to twenty-four tons of coals weekly,
in the furnace only. A furnace of twelve pots, exposing a
much larger unoccupied area, in comparison with a ten-pot
furnace, will consume nearly double the quantity of fuel;
whereas, twelve pots of melted metal will hold only in the
proportion of one-fifth increase. Furnaces of less dimensions

" FLASHING."

61

than eight pots are objectionable, through the great loss of
pots in consequence of the comparatively small size of the
siege, as before explained.
The manipulatory operations of Glass-making are totally
dissimilar to casting metals of any kind. Scarcely any advance in this department of the manufacture has been made
for above two hundred years; and the tools then used for
blowing, and shaping the various articles have been since
but little improved. The reason is obvious: the formation
of the infinite variety of wares produced in Flint Glass-houses,
relies more upon skill, adroitness, and tact, which may be
termed the main-d'oeuvre of the art, than upon the ingenuity
of the tools:—in truth, the perfection of the product of the
furnace, as regards its workmanship, depends chiefly upon
the tact and intuition of the Glass-blower, avoiding as
much as possible the use of tools. The more these shape
the article, the more imperfections are likely to be produced by the scratching and rubbing of the iron; although
this is partially avoided by the use of modern wooden
charred tools. Iron tools should only be employed in the
earlier process to produce the crude form, and the wooden tool
used but sparingly ; whilst the finishing and intermediate
shaping depends chiefly upon the application of centrifugal
force, by rapid hand rotation; upon the expansion given to
air to widen the forms while reheating at the aperture of the
furnace, technically termed "flashing;" and upon a skilful
final throw.

62

CURIOSITIES OF GLASS-MAKING.

ANNEALING.

Heat more or less expands all metals, which again contract
in the cooling; and, with the exception of cast-iron under
peculiar circumstances, no danger of fracture is caused even
hy rapid cooling. Flint Glass, on the contrary, owing to its
peculiar crystalline structure, especially when of unequal substance, is subject to fracture by sudden exposure to friction or
the ordinary temperature of the atmosphere, and particularly
so in frosty weather; it cannot, therefore, be too carefully
cooled to allow a gradual contraction, and the crystalline
particles to settle equably into their ultimate position. The
process of annealing becomes to the workmen and manufacturer of the greatest importance, and needs the most careful
and scientific arrangements to prevent cold currents of air
from coming in contact with the glass while gradually parting
with its caloric. Metals being more or less crystallizable, under
some circumstances, are subject to fracture by a sudden blow or
friction; and Glass exceeds every other crystallizable sonorous
body in this peculiarity. No contrivance can be practically
too costly, which will effectually anneal so brittle a material as
Glass; and it is false economy to save fuel in the process,
when a greater body of caloric, at a greater cost of fuel, would
give additional security. Fracture is supposed to arise from
derangement of the atoms by unequal contraction or tension .
thus, the interior of a hollow vessel taking more time to cool
than the exterior, tends, by unequal contraction, to derangement and fracture, by crushing the particles; and this can
only be remedied by the external heat of the annealing fire
allowing the two surfaces to cool simultaneously. The more

ANNEALING.

63

massive, therefore, the Glass is, the more difficult it is for the
caloric safely to be given off. Therefore, when a piece of Glass
has to be reheated, as in the case of a lamp Glass, it should be
of a medium thickness; not too thick to prevent the heat from
quickly travelling through its substance; nor too thin, to be
subject to break by the friction or tension of cleaning. The
same remarks will apply to tubes intended for steam gauges:
which should be subjected to special care and time in the
process of annealing. Hot water, or heated sand, would be
equally serviceable as an annealing medium: heated air is
most convenient for general purposes, although the two former
are occasionally used.
A piece of unannealed barometer-tube, forty inches long,
measured when just drawn, will become about one-fourth of
an inch shorter if annealed; whereas, if quickly cooled without
annealing, it will only contract about one-eighth of an inch,
Should Flint Glass of unequal substance be insufficiently annealed, such as is not broken in cutting may be placed in a
sand and water bath nearly cold, there very gradually heated
to the boiling point, and kept several hours in a state of ebullition; the heat may then be reduced, and the whole suffered
to get gradually cool. This process has scarcely ever been
found to fail.
However carefully tube gauges for steam-boilers may be
annealed, even after long use, great danger is caused by
cleansing the inside: it is well known that a few grains of
sand shaken inside a piece (or proof) of unannealed Glass
will cause a violent fracture; and the same effect to a less degree may be produced in an annealed tube. Probably the outside, being more exposed to the lear fire, gets better annealed,

64

CURIOSITIES OF GLASS-MAKING.

and becomes more contracted; consequently, an unequal tension disturbs the inner crystalline particles, when deranged by
the interior friction of cleaning. Striated tubes should not be
used for steam gauges, as the striated parts will not contract
or expand uniformly with the parts that are free from striae.

F r o n t view of t h e annealing arches, showing three sets of pans heating each
w i t h a separate fire, w i t h t h e same cylindrical "brick arches and cast-iron
doors

A lear is the term given to an arch, or oven, open at both
ends. Each lear has a small furnace at the receiving end or
side nearest the large Glass furnace; the hot end may be
termed the receiving end, and the cooler the discharging end;
the latter terminates with a chimney, and the hot end is kept
at a temperature just short of a melting heat. The caloric is
sustained by oven-burnt coke, which imparts, decidedly, the
most regular heat for annealing, and is the freest from
smoke, the carbon of coal smoke being generally injurious
to the colour of the Glass. There are from two to four of
these semi-cylindrical arches, built side by side; on the
floors of these are placed iron pans to receive the manufac-

ANNEALING.

65

tured goods, which travel upon a miniature railroad gradually
downward from the heated to the cooler end, a distance of
about sixty feet: one-fourth of the length of this distance is
arched, and leads into an air-tight receiving or sorting room,
from which the goods are ultimately removed. If there be two
or more lears, or arches, in one house, there should be various
degrees of heat in each ; the highest being intended for strong
goods for cutting, the medium for the ordinary run of table
Glass, and the lowest for vials or light lamp glasses.
The time for annealing varies from six to sixty hours, the
weighty articles requiring the most heat and time. The best
arrangements for annealing may be foiled, should the Glassblower unnecessarily lose time after finishing the work; as the
hotter the goods enter the arch, the better; on this account,
the large goods receive a final
reheating at the mouth of a
pot heated by beech-wood, and
called the Glory Hole. Successful annealing depends much
upon the proper direction of the
wind : the best aspect for this
purpose is when it passes over
the fuel of the lear toward the
lear chimney, so that the hot
air is always radiating in the
downward current upon the
°ry
goods. Great losses accrue from breakage, when an upward
or contrary current of wind drives back the heated air from
the cool or chimney end, toward the fuel at the upper end.
While annealing, the lower, or discharging end of the lear,
K

66

CURIOSITIES OF GLASS-MAKING.

was formerly always under the lock and key of the Exciseman; often to the great injury, and always to the great inconvenience, of the manufacturer.
Goods for cutting, requiring extra care and time in the lear,
are protected from cold draft under semi-cylindrical arched iron
covers, technically called " omnibuses;" or, when very massive,
the goods are immersed in hot sand. Kilns were formerly
used for annealing almost universally to render the Glass fit
for the severe friction of deep cutting. There is a great distinction between a kiln and a lear. The kiln, when in use, is
closed at the further end; whereas the lear is open at both
ends. The kiln, when filled with goods carefully placed in
pans, is closed, with the burning fuel also; the openings, or
interstices, in the event of the door not shutting accurately,
are sealed up with clay; and the time required to cool is usually
about a week. This period seems very long in comparison with
the short time allowed for the lears; but, as the Glass in the
kiln is immured with the burning coke, which consequently
parts with its caloric very slowly, it will require nearly
that period to allow the Glass to become sufficiently cool to
be handled, or to expose it to the ordinary temperature of the
atmosphere. The lear admits the goods to be continually
drawn more quickly, although by slow degrees, away from the
burning coke; and the glass, therefore, more readily cools.
Kilns are objectionable through causing so much delay; and
dispatch being the order of the day, they have been superseded
by the use of iron covers, or sand, in lears, as already stated:
likewise by lengthening the lear fire-places, and not filling
the pans with Glass too fast, as well as by great attention to
the regularity and intensity of heat; it being the instruction

EXCISE

REGULATIONS.

67

to the lear-man, or fireman, rather to run the risk of melting
goods hy excess of heat than subject them to fly by insufficient
heat.
Cast-iron doors, making the openings toward the Glasshouse larger or less at pleasure, are a great improvement;
these openings should always be as small as possible, except
when the larger goods are admitted. They are closed effectively but once a week. When the Excise upon Glass existed>
the lear was secured by fastenings and locks,—supplied by the
Government officer at the expense of the trader, and safely
secured every Friday or Saturday, and not re-opened till the
Monday following. During the whole of the week, the officer
had the surveillance of the lear, but especially of the sortingroom (at the delivery end of the lear), which was only entered
at the stipulated Act of Parliament periods. If a link forming
part of the endless chain running under the lear, connected
with the machinery, drawing down the pans, accidentally
broke in the night, and the officer should happen to be absent,
(which was rather the rule than the exception,) either the
whole works must be stopped, or some mode adopted for the
learman to repair the mischief not strictly in keeping with the
Act; so that while the principal was quietly reposing in his
bed in imaginary security, his servant, unknown to him, had
almost necessarily incurred ruinous Excise penalties. The
Excise officer gauged the liquid Glass in the pots, which he
had the option of charging by weight, at a specific gravity of
82 00; and should the manufactured annealed goods ultimately
not amount to two-fifths of that estimate, he had to pay the
difference. The lear charge was always considered to be the
chief security, < S indeed it really was; still, with the utmost
A

68

C U R I O S I T I E S OP

GLASS-MAKING.

Excise vigilance, the trader occasionally defrauded ; but owing
to the great heat of the arch, and the usual Excise securities,
the revenue was, on the whole, well secured at the lears.
Had the lears or kiln been the only departments of the works
under Excise survey, the manufacturer would not have been
so much inconvenienced. The surveillance of the pots was
his chief annoyance, since it required endless trouble, and
subjected the manufacturer to danger of Exchequer prosecutions. To throw into the pots ever so small a piece of metal,
during the working, incurred a penalty of fifty pounds for
every offence. Neither plate Glass nor bottle Glass manufacturers were subject to the surveillance of the pots: this
made it exclusively injurious to the flint Glass maker, and
was almost a prohibition of alteration of tint, or experiments,
and consequent improvements.
It is matter of astonishment how Elint Glass works
existed at all under such a concentration of commercial
and manufacturing hinderances as were imposed by the
Excise regulations; happily, the incubus exists only in reminiscence.
To return to a few of the curiosities of Annealing. Coke,
as has been stated, is the best fuel for this process : it is
the most steady and uniform in its calorific powers. Ovenburnt coke is stronger and much more lasting than gas
coke ; another advantage is, that it is the most free from carbonaceous fumes, or smoke. Eluid Glass need not, therefore,
be tinted in excess, only a minimum quantity of manganese
being in such case necessary. If coal be used, the smoke, acting by its carbon upon the Glass, will render colourless the

DEVITRIFICATION.

69

reddish tint arising from a maximum or excess of manganese ;
or, if the glass be previously colourless, it will cause a greenish
tint to appear, which the manganese had dissipated: therefore, carbon would seem to be a neutralizer of oxygen, and
practically a dissipater of the colour, caused by manganese.
But should the Glass thus lowered in tint be re-melted, or
only softened by the drop pincher, in moulding it into
prisms or ornamental drops, the reddish tint will again
appear; as if (which is probably the case,) the carbon received
in the annealing had again been dissipated, and replaced by
oxygen in the process of pinching. However massive may
be the piece of flint Glass, which is the medium of these
changes, the purple tint of the manganese, the greenish
hue from iron, (the impurities of the lead or other ingredients,) not only adhere to the surface of the Glass,
skin-deep, but extend to every particle of the central and
general mass. That these alternate changes are the result
of two antagonist chemical agents appears confirmed by
the fact of Glassmakers resorting to carbon for the neutralization of the manganese reddish tint, when in excess in
the fluid Glass; this is done by agitating it in the pot with a
wooden pole or burning staff, the carbon from which is found
to have the effect of dissipating the manganese colour. An
excess of nitrate of potash or soda has somewhat the same
colouring effect as manganese, arising probably from its
abundance of oxygen.*
* The Glassmaker is well aware, when mixing materials for filling the
pots a second time in the same week, consisting chiefly of cullet, or broken
Glass, and saltpetre or other alkali, with but little if any new or virgin

70

CURIOSITIES OF GLASS-MAKING.

Devitrification, which is caused by excessively slow cooling,
occurs more frequently in the simple than in the compound
Glasses, and destroys the crystalline properties of Glass. Its
appearance in crown or common bottle Glass is that of a
multiplicity of small petrified star-fish, or rays diverging from
different centres, in little groups resembling an opaque or
partially opaque whitish clay, or Keaumur's porcelain occasionally, surrounded by or encrusted within the transparent
Glass; when it exists in great masses, prior to its becoming
quite opaque, it has a beautifully variegated effect, like a precious stone. It is the bane of the Glassmaker, and occurs when,
from a state of fusion, the Glass is allowed to cool too slowly.
Sir James Hall, in investigating the cause of devitrification,
gave a piece of green Glass this opaque character by very
slow cooling; but the Glass, in re-fusion, required a very intense heat to cause it to resume its transparency. Whatever may be the cause, Glassmakers well know the remedy;
and when, from certain tendencies, this annoyance is likely
to occur, if there be thrown into the fluid Glass a quantity
of common clay or silicate of alumina, it will soon become
fused in the mass, and prevent the evil. Partial devitriflmaterials, of sand, alkali, or lead, for what is termed an overtaker,—that he
needs no additional manganese to neutralize the greenish tint. Dr. Faraday
observes upon heavy Glass, which in one of his experiments had Flint Glass
mixed with it—" The Glass, when finished and cold, was of a deep purple
colour: this was immediately referred to the manganese in the Flint Glass,
a supposition proved by repeating the experiment with other Flint Glass,
and then with Flint Glass of our own manufacture, in which no manganese
was used; the latter Glass gave no purple colour; the former, a colour as
deep as the first Flint Glass."

P H E N O M E N A OF ANNEALING.

71

cation occurs on the surface of Flint Glass in a species of
cloudy, diminutive, white, starry crystals: it is supposed to
arise from impurity of alkali. This curious semi-roughed or
opaque effect is seldom found in Flint Glass of an open form,
but usually on the surface of the inside of a close Glass vessel
towards the bottom; the stars are much more minute in Flint
than in bottle Glass, and no acid or alkaline application will
remove it when the Glass has become cold. If its existence be
noticed before the workman has finished the partially devitrified
piece of Glass in hand, it may be remedied by thoroughly remelting the Glass sufficiently long, until the partial opacity is
dissipated. This defect very rarely occurs when the American subcarbonate potash has been well purified; whereas, it
is often caused by the use of the Birmingham ashes, most
probably from their not being sufficiently free from sulphates or muriates. In specimens of old Venetian Glass,
(without lead,) the interior surface of a vase is often
found devitrified towards the bottom and centre; should
it have but a small opening, a hollow handle may have its
interior affected in the same manner, as if it were roughed;
whereas, an open foot or lip of the same vase may be perfectly
transparent and free from semi-opacity, owing to the remelting of the two open parts; whilst the body of the vase,
having only a small opening, or mouth, fails to get heat
enough to remelt into transparency the devitrified part.
Annealing may sometimes appear complete in Glass articles
that have borne the friction of deep cutting ; which, when long
after exposed to the influence of the atmosjDhere, become fractured, as it were, spontaneously. A large quantity of Flint,

72

CURIOSITIES OF

GLASS-MAKING.

or compound Glass, manufactured at the Falcon Works, (of
a beautiful topaz tint, coloured by uranium, which became
richer in hue by diminishing the usual proportion of lead, and
by increasing the alkali,) fractured three months after it was
cut. Complaints from purchasers at home and abroad reached
the Works, and the whole had to be replaced at the expense
of the manufacturer.
Excess of alkali causes continual exudation; the cementing property escapes, entire fracture is the result, and no
remedy can check the evil. A piece of ancient light blue
Glass, since it came into the possession of the British Museum,
has spontaneously fractured, and some parts almost to pulverization; an effect caused by its excess or impurity of
alkali.
Formerly, lears were heated by the waste caloric of the furnace ; they were elevated about six feet or more from the floor
of the Glass-house, to catch the flame and warmth from the
top of the furnace flues. This contrivance saved the entire
lear fuel; but from the inconvenience and breakage caused
by the Glass being taken up steps, and the impossibility of
regulating the heat and smoke, it has been long since disused in England. Modern lears are placed a few feet
above the floors of the Glass-house, as already described:
they not only anneal the Glass better, but the saving
of breakage, in comparison with the old system, is found
to be considerable, and wholly covers the expense of separate fuel. The amount of breakage in the lears varies
considerably: the minimum average may be taken at 2 per
cent, upon the manufacture; under unfortunate or bad

COLOURED

GLASS.

73

management, the maximum of breakage may be calculated at 10
per cent. Next to the duration of pots, the success of the manufacturer depends upon constant attention, and skilful management of the lears.*
COLOURED GLASS.

Dark, massive, coloured Glasses, formerly made in Flint
Glass-houses—whether blue, green, amethyst, or other colours,
for hyacinth, hock, and finger glasses, or in large cylinders
for cutting and flatting into Window Glass—have been almost
superseded; the latter by Crown Glass-makers, and the
former by lighter or less dense Flint Glass colours.
The introduction of toilet and smelling-bottles has created
a demand for light-tinted Glasses, particularly for the beautiful semi-opalescent, yellowish-green colour; produced chiefly
by the expensive oxide of uranium, mixed with a slight portion of copper, and appearing yellow or light green, just as
the rays of light happen to fall upon the unequal substance
or thickness of the Glass. This chameleon-like effect is also
produced by uranium alone, used as the colouring oxide
for gold topaz: it has been much in demand for hock
glasses and decanters, and many ornamental articles of glass;
but its fascinating peculiarity is lost, indeed, its colorization
mostly fades, by candle-light.
The superior purity and refractibility of our Flint Glass is
particularly adapted to display the delicacy and beauty of
* Unannealed Glass exhibits the effects of polarization of light; which
being a philosophical subject, is not considered sufficiently practical to come
within the plan of this work.
L

74

C U R I O S I T I E S OF

GLASS-MAKING.

these light tints, and gives a decided superiority to English
over foreign Glass. Dark colours are not used en masse as
formerly, owing to a great loss of light, and apparent shadowy
blackness, which is avoided by the modern practice of casing
Mint Glass with one or more thin coatings of intensely coloured
Glass ;*—whether of blue from cobalt, green from iron and
copper, ruby from gold; or any colour, made from other
suitable oxide of metal.
The density of the colour may be varied—darker or lighter,
according to the quantity of colouring oxide used, but it
is indispensable that the oxide should be perfectly pure;
and the various Glasses, whether transparent or opaque, requiring to be welded, or cased, upon each other, in one homogeneous mass, should be of the same specific gravity; therefore, in mixing, where a large quantity of colouring oxide is
used, less lead must be employed, so as to equalize the composition, and render uniform the contraction and expansion
of the various layers of Mint and Coloured Glasses.f
The Glass-maker must be ever on the watch for these
essential conditions, or great losses will occur in the operation
* See the manipulatory explanation of Cased Glass, termed by the
French, Double-Triple, &c.
f The artists of the middle ages leaded their beautiful tints of blue, red,
yellow, amethyst, and green, into windows, either thicker or thinner, of solid
or cased Glass, as the required effects suggested. They also cased a
greenish glass with transparent dark colours, occasionally cutting through
the coloured casing to show white alternately, and staining with yellow the
white parts thus cut out of the colour. Modern Glass-makers produce as
fine colours as those of mediaeval manufacture, but time having slightly
dimmed or decomposed the surface of many of the fine old windows, a rich
subdued beauty of colorization is produced, that cannot be imitated in new
Glass.

COLOURED GLASS.

75

of cutting. The colours for casing should not remain above
two weeks in the pot without being ladled out, and mixed
with fresh batch, oxide, &c, as the specific gravity becomes
altered by too long exposure to heat, and the Glass injured
by evaporation of some of the materials. The severe friction
of stoppering is very apt to break cased Glass, unless stopped
after cutting; by this means, much of the danger is avoided,
especially in single casing. The greater part of the coating
being removed by cutting through the exterior, in forming the
ornamental pattern, the unequal tension of the two glasses is
almost wholly prevented.
It is said that the French first used violet Glass for ripening
grapes, and for other horticultural purposes. The rationale
adduced was, the partial exclusion of the calorific solar
rays, and the greater encouragement of the chemical rays. The
experiment has been tried upon a large scale, near London ;
but whether owing to the glass being of too dark a colour, or
to unskilful horticultural management, it did not answer.
French beans and strawberry-plants under this glass grew
rapidly, but were long, spindly, and tremulous; and not appearing likely to come to perfection, the coloured Glass was
removed from the greenhouse.
The author tried some of the same Glass in a frame,
upon a very fine cucumber-plant, with two branches shooting
out in opposite directions, each having blossomed and being
about to fruit; when the branch placed under this coloured
Glass, became feeble and diminished,—both leaves and fruit
being very diminutive, in comparison with the other half of
the plant, under the usual greenish Crown Glass, which perfected its fruit to a large size, and of excellent quality. The

76

CURLOSITIES OF GLASS-MAKING.

stunted growth of the portion of the plant under the coloured
Glass was, no doubt, owing to the colour being too dense,
and thereby excluding too much light.*
The ancients were acquainted with the use of the following
metals for tinting Glass, as the analysis of various specimens of Eoman and Grecian fragments prove—viz., copper,
manganese, and iron; the latter, employed in different proportions and admixtures with other metals, produced a beautiful azure blue, nearly equal to the rich modern cobalt colour.
See plate 2, and the following table of analysis by Klaproth:—
Red Glass.
Blue.
Sand
162 ... 163
Oxide of Lead, Blaoxide 28
1
Oxide of Copper . . .
15
Iron oxide
5
19
Alumine . . .
2
3
Kalkerede, Lime .
3
05

Green.
130
15
20
7
11
13

.

.

195
5

186
14

196
4

200

Loss

200

200

The above red and green Glasses are chiefly coloured by
* A very light green is found to answer better than a colourless glass for
conservatories; and, by recommendation of Mr. Hunt, author of " R e searches on Light," &c, the new conservatories of the Royal Gardens at
Kew have been glazed with this description of flat Glass, in order to afford
the plants protection against the scorching heat of the meridian sun. A
great improvement would be effected by the panes being of an arched form,
and placed in such an aspect that the morning and evening rays of the sun
would not have a tendency to reflect the rays back again, as is the case
with thick flat Glass, in which, when the rays pass through it at right angles,
parts of irregular substance act as burning-glasses; whereas, by the above
arrangement, the rays would pass in a direct course through the glass;
and within, the condensed drip would be effectually carried off by channels
on each side of the interior of the frames.

77

COLOURED, GLASS.

copper, and the blue with iron. The latter dark azure ironblue was, probably, the produce of the Alexandrian furnaces,
at a very early period of Glass-making: it was obtained from
iron by the late Mr. James Green, who, so far, confirmed
Klaproth's analysis. The specimen of the Egyptian idol, and
the lachrymatory vase found by Mr. Banks, at Thebes, in
Plate &, are of this variety. Cobalt was probably not used for
Glass colorization till a much later period : the Portland Vase
and the Naples Yase (Plate No. 1) have, no doubt, crude
cobalt for their colouring base (of the dark rich blue);
whether they are late Egyptian or Grecian manufacture, it is
difficult to decide.
The foregoing and the following analysis of coloured
Glasses are extracted from a work by Minutoli, published at
Berlin, in 1836, entitled " Uber die Anfertigung und die
Nutzanwendung der Farbigen Glac^r bei den Alten:"
Green.
Silica
Oxide of Lead
Oxide of Iron
Oxide of Copper

0-439
0*357
0-016
0-131

Difference

0-943
0-057
1-000

This difference is conjectured to be potash or alumine.
Flint Glass manufacturers produce a beautiful red from a
mixture of copper and iron, and sometimes accidentally:
for instance, when the ordinary metal mixed specially for
light green medical bottles, is nearly worked out, it will
assume the complementary colour—viz., a ruby red; so that
the same bottle will be parti-coloured red and green. The

78

CURIOSITIES OF

GLASS-MAKfNG.

chemistry of colours depends upon a very nice adjustment of
relative quantities of carbon and oxygen, as well as of colouring oxide, and of alkali or lead. Uranium is specially
affected by an excess of alkali, the colour varying from deep
gold topaz to light amber-like opalescent green, as the alkali
predominates. The proportion of lead is diminished in either
case; and although an excess of alkali extracts most colour
from the oxide, it renders the Glass liable to become unhomogeneous, by the exudation of its alkali. It is to be regretted
that the specific gravities are not given by Klaproth in his
analyses.
Notwithstanding the use of oxide of lead by the ancients
in their coloured Glasses and artificial gems and enamels, the
lightness of the fragments of their white cut Glass indicates
the absence of lead from the constituents of much of the
ancient artificial crystal. A fragment in the possession of Mr.
Koach Smith, alluded to in another part of this work, and
introduced into the coloured Plate (3, fig. 3) can have no lead in
its constituents, as its specific gravity is but 2*049 ; Flint Glass
of the ordinary gravity being 3*200, Plate Glass about 2*500,
and real crysta] about 2*500. No doubt, this relic possessed a
large quantity of alkali, probably carbonate of soda or potash,
part of which has exuded by lapse of time, leaving the entire
atoms or particles of undecomposed silex; thus rendering the
glass less compact, of diminished specific gravity, and less
conservative. These fragments probably formed part of a
Koman white drinking-glass, which, in the days of ancient
Eome was scarce, and highly valuable. Had lead formed one of
its constituents, the Glass would have been more permanent;
the surface would not have been so much decomposed and
"crazed/' as it is technically termed, leaving more or less

GATHERING FROM THE FURNACE.

79

numerous small cracks, extending about half-way through the
Glass. Although decomposed on the surface, part of it is
rough, as if treated by sand friction, to produce a contrasted
effect, such as is employed in our times. The recently fractured parts are quite bright, colourless, and transparent, and
melt with the blow-pipe, (but not very readily;) proving the
fragment to be artificial, and not real crystal, as at first the
author was led to conjecture.
STATE OF T H E FURNACE AT T H E
WEEK'S

COMMENCEMENT OF T H E

WORK.

After the fused Glass has been lowered in temperature, so
as to reduce it from a watery condition of fluidity to about the
consistence of honey or treacle, it is fit for gathering, as it is
Gp termed. Gathering is effected
^?^*^
by the workman heating to
/^
m^^*^^
nearly a red heat a hollow blowm^-^^j^^
ing iron, at the larger end;
Bsf^flflf
this he places in the pot, in
l|Mj||JjHj
contact with the surface of the
^^MMtf'
metal, to which it instantly
adheres; at the same time, the iron is kept in constant
rotation by the blower until the requisite quantity of metal is
gathered. Should a large quantity be wanted, the first gathering must be taken out of the pot, and cooled by exposure to
the air; and when the lump is somewhat consolidated, another
gathering upon it may be made from the surface of the metal,
and even a third or fourth gathering, until mass enough has
been accumulated to make as large an article as the workman
is capable of handling.. The weight of each gathering is
increased in cubical proportions; the first gathering being

80

CURIOSITIES OF GLASS-MAKING.

usually about eight ounces, the second four pounds, and the
third sixteen pounds. Of course, each time less weight may
be taken if required. Accidents to the men by burning seldom
occur in a manufactory so as to incapacitate them for work;
and when they happen, they are more the result of carelessness
than otherwise. A stranger need never feel nervous on entering
a Glasshouse in full work, although he might suppose that hot
Glass swinging about would often lead to accidents. Visitors
are much more likely to receive a blow or a burn by moving
about to avoid the men, than if they stood still, and allowed the
blowers to swing the glass in their usual way. A few years
since, a man was severely scalded, and confined to his house
about six weeks, through falling back, after pot setting, into
a caldron filled with water, standing in the Glasshouse, into
which the remaining contents of the pots had been emptied
at the end of the week; this did not occur in the course of
his duties, but by what is termed " larking." He was dreadfully scalded, but not burnt with the fused Glass. A pump
being in the Glasshouse, cold water was abundantly poured
upon the scalded parts, the man was carried home, and attended
by a skilful medical man; and after several weeks of suffering,
he recovered, and returned to his work.
MANIPULATIONS.
The manipulations of Glass-making may be divided into
four principal operations—viz., 1st, blowing and making by
Hand; 2nd, in Moulds; 8rd, a more recent introduction from
North America—viz., pressing in moulds by Machinery; and
4th, Tube-drawing. When these have been delineated, the
Curiosities of the Ancient and Mediaeval Manufactures will
follow.

81

TOOLS FOR

MANIPULATION.

Glass-makers' tools are but few in number, and extremely
simple. The pucellas, A, is somewhat like a pair of spring
sugar-tongs, the prongs resembling the
cutting parts of shears, but blunt, and used
for rubbing the outside of solid or hollow
glass, and pressing it into a diminished
diameter, at the same time elongating the
parts by the chair-rotating process. This
tool does the same duty as the cutting tool
of a lathe; but instead of removing chips
or waste, (as in the process of reducing the
diameter of the wood or metal,) it simultaneously squeezes and lengthens. (See
Wine-Glass Chair, at p. 83.) This principal
tool is also employed to open or close the
insides of wine-glasses, bowls, jugs, vases;
and to shape generally the Glass, as it
rotates at the pleasure of the workman.
The spring tool, B, is a species of tongs
for laying, hold of half-formed handles,
and generally to seize Glass while making. The shears, c, are but strong ordinary scissors, used for cutting off the surplusage of glass handles, and to level the edges of bowls of
wine-glasses, &o. Much skill is required to shear a wine-glass:
it is held upon the iron by the left hand, and rotated
towards the shears, which are grasped in the right hand
M

82

CURIOSITIES OF GLASS-MAKING.

of the workman. A well-skilled workman can shear a glass
entirely round the bowl at one operation. In Bohemia and
Germany, generally, the workmen are said not to be sufficiently
skilful to use the shears; but the edges of bowls are blown
in the rough, and cut smooth by the glass-cutter when cold,
which leaves a flat and unsightly finish, far inferior to the
round, smoothed edge of fire-polish after shearing. The
battledore, D, is another simple tool that needs no explanation.
These, with the compasses and the measure-stick, are the chief
tools, except the pontil and blowing-iron, which are very
simple instruments: the latter is a hollow tube, (about four
feet long,) lessened at the mouth and enlarged at the end,
for gathering j;he metal. The ponty, or pontil, is a solid rod,
used to support the Glass while working, when the blowingiron is no longer needed. The sizes of both these rods are
heavier and lighter, according to the nature of the work.

The marver, L, (a corruption of the French marbre, marble
being formerly employed,) is a slab of cast-iron, about one

TOOLS FOR

MANIPULATION.

83

inch thick, with a polished surface, placed upon a wooden
stand: upon this slab, the lump of glass is rolled to give it a
regular exterior, so that the result of expansion by blowing
may be uniform in thickness of metal.

Glass-maker's Chair,

• The Glass-maker's chair, M, is used chiefly by the workman,
although occasionally by the servitor and footmaker. It consists of a flat seat of timber, about ten inches wide, each end
being fixed to a frame, connected with four legs and two arms
—the latter upon an incline. An edging of wrought iron is
screwed upon these inclined planes, for rolling the blowingiron, with the hot glass at the end of it, backwards and forwards with the left hand; thus causing the rotatory motion of
a pole lathe, while the right hand, with the pucellas, gives the
requisite form.

MANIPULATOKY

PEOCESSES.

BLOWING AND MAKING BY HAND.

We will now attempt to describe a few of the manipulations
of the Glass-blower, beginning with a wine-glass, which will
explain also the mode of manufacturing a goblet, and nearly
all vases or articles having three pieces—viz., a bowl, stem,
and foot.
WINE-GLASS IN THREE PIECES.

A, is the ball
of hot Glass,
which adheres
to the hollow
blowing iron, B ;
and this, after
being rolled on
a polished castiron slab, called
a marver, L, and
expanded a little, in preparation for the bowl
of the wineglass, c, further
shaped, has the
end rubbed with
the battledore,
to flatten it. D,

r=l|
A

**ST-

H H

BLOWING AND MAKING BY H A N D .

85

is the same as c, but
with a solid ball
adhering to the flat
part of the bowl;
this being a separate
gathering, out of
which the stem has
to be lathed, or
shaped, by the tool
called pucellas, as E, while it is rotating up and down upon
the inclined planes of the Glass-maker's chair, which serves
as a lathe. The stem is thus shaped ready to receive the foot.
The moment the Glass gets hard by cooling, the rubbing of
the pucellas must be discontinued, or an excoriated surface
will be the consequence, F has the globe attached to the
stem, which is afterwards opened and flattened by the pucellas into a foot, while lathed, or rapidly rotated, as G, on
the arms of the blowing chair, H is the same, with the iron
pontil adhering to the foot by means of a small piece of gathered glass. The pontil secures the whole preparatory to its
being whetted from off the bowl, and released from the blowing-iron at the dotted line, H H, by the touch of the cold pucellas, contracting and slightly fracturing the Glass, which is
subsequently cracked through the entire circumference by a
smart blow of the pucellas. I, is the bowl under the operation
of shearing, so as to make it perfectly even, and fit it for the
flashing and finishing, K, which is finally knocked off for
annealing from the end of the pontil by a sharp blow.

86
WINE-GLASS, GOBLET, OR ALE-GLASS, IN TWO PIECES.

Usually, Wine-glasses are made in three pieces; those in
two pieces, like the following, have the stem drawn out of the
bowl. The first gathering is as
usual, A ; it is then expanded, swung out, and elongated,
as B ; from the thick part, c,
at the bottom of the bowl,
the stem is drawn out with the
pucellas while rotating, until it
gives the form, D. Of course,
during the drawing, it has to be
rubbed by the pucellas on the
inclined plane of the blower's
chair, and rewarmed as often as
necessary; when whetted off at
the dotted line, E, it is prepared for shearing, as sketched
in the former diagram; so soon
as the foot is added and opened,
as F, and sheared, the bowl is flashed and finished, as G.
This form is often adopted for hock and claret glasses. When
made very slight, the stem is so attenuated as to be scarcely
thicker than a straw.
Between every operation, as before described, the Glass
must be submitted to a fresh heat in the mouth of the pot,
that the parts required to be shaped may be pliable, soft, and
easily impressed by the pucellas. The re heating is also
essential to the welding of one piece to another—viz., the
stem to the bowl, and the foot to the stem. After the bowl is

MODE OF PAYMENT, E T C .

87

sheared, it is re-heated and softened : this is done by rotating
it with rapidity in the pot-hole, occasionally withdrawing it,
to take into the bowl comparatively cool atmospheric air;
again bringing it near the mouth of the pot, so that the expansion of the air within the bowl, the centrifugal force of
rapid rotation, technically called flashing,* and the final skilful
throw, may give the finished form. A little help may be
required from the tools, the use of which, however, should if
possible be avoided. The charred wooden tool only must be
used, in case the flashing of the bowl should throw the glass
out of form. To make a number of wine-glasses free from
tool marks, and exactly of one uniform size, &c, requires the
workman, or chief, to be of superior tact and skill, supported
by an excellent servitor and footmaker.
MODE OF PAYMENT, DIVISION OF LABOUR, E T C .

Before entering into further details of Manipulation,
a few explanations relative to the system of paying the workmen, their customs, &c, may be requisite.
The productions of Hint Glass works, in their varieties and
divisions of labour, are somewhat like that of a well-conducted
farm, on the four-course system, yielding its due proportion
of cereal and leguminous crops alternately. Flint Glass works,
to be profitable, cannot yield the whole of the product of
* This is but a modification of the flashing process, fully described and
illustrated by G. R. Porter, Esq., of the Board of Trade, author of Treatises
upon Flint, Crown, and Plate Glass," Lardner's Encyclopaedia." (See Crown
Glass, page 185.) Much valuable information may be gathered from the
perusal of the whole of the articles on Flint, Crown, and Plate Glass,
particularly bead-making, and many other topics not referred to in this
work.

88

C U E I 0 S 1 T I E S OF GLASS-MAKING.

the finest quality, any more than a farmer can grow wheat to
the exclusion of every other produce; and whoever makes
that attempt, will, in the end, find out his error. A ten-pot
furnace, filling nine pots weekly, besides overtakers occasionally, (the tenth being an empty pot for the castor-hole workman,) may employ five chairs of workmen, changing alternately
every six hoars, day and night; there being five chairs at work,
and five chairs at rest.
The four-chair system is, however, the mode usually adopted
—viz., the first is termed the castor-hole chair, consisting of
workman, servitor, footmaker, and boy, for making large
goods, such as carboys, and large show-rounds for the chemists'
windows, milk pans, handled quart and pint jugs, decanters,
semicircles, for roughed lamp shades, &c, Tall or muscular men are employed in this department; as occasionally, goods of thirty or forty pounds weight of Glass will
require great power to work into form, the leverage of the
blowing iron giving additional weight to the article under
manufacture. An empty pot, heated with dried beech-wood,
is used by the workman at the castor-hole for re-heating the
Glass.
The second chair consists of a workman, servitor, footmaker, and boy, for making fancy articles, and goods required
for cutting—viz., toilet and smelling bottles; also tube-drawing
in all its operations, for barometer, thermometer, and steam
guages., as well as chemical apparatus of small size, &c. The
Glass for these purposes is re-heated at the mouth of one of
the pots containing fluid Glass.
The third chair, consisting of workman, servitor, footmaker, and boy — is almost entirely occupied in making

MODE OF PAYMENT, E T C .

89

wine-glasses, goblets, tumblers, lamp-chimney glasses, and a
few other miscellaneous articles. This department, and the
first and second chair, require workmen of considerable tact
and skill.
The fourth chair does not need the skilled workman of the
three former; the men are paid inferior wages, especially as
their productions secure less remunerative prices; they, however, require to be remarkably active. One finisher and two
blowers, with a boy to keep the mould warm, (with lumps of
hot glass,) and another boy as taker-in, are requisite. Thus,
phials are re-heated for forming the brims, by a plus pressure
of flame proceeding at once from the furnace.
The above four sets of workmen, with a teazer and lear
man, changing every six hours, constitute the complement
for one furnace; four sets being at rest while other four
are employed. Some manufacturers dispense with the bottlechair, and have in place of it another wine-glass chair, or such
substitution as best suits their particular trade.
Glass-blowers have arrangements as to their classes and
modes of operation, probably unlike any other branch of
trade, being divided into four different coteries, or " chairs,"
as they are technically called; three of each having their chief
—viz., first, a gaffer, or workman; the second, a servitor; and
the third, a foot-maker; the latter usually earns about half
the wages paid to the chief, and the servitor receives an intermediate amount. The boy, or taker-in, is paid separately,
but also by the piece, according to the earning of the chair.
Three of the chairs are thus manned.
Boys of ten years old, after being three or four years takersin, and availing themselves now and then of the opportunity
N

90

CURIOSITIES OF GLASS-MAKING.

of a little practice, (by stealth or favour of the workman,) become qualified as footmakers. The mode of reckoning the
piece-work of Glass-makers is peculiar. The " move," as it
is technically called, is a nominal period of six hours; and
the payment is proportionate to the number of articles supposed, by fair exertion, capable of being made in that time by
a set of ordinary workmen. The move being fixed at two hundred for small moulded bottles, (for one chair,) and sixty
wine-glasses being also considered as the fixed number for
another chair, it might be supposed that the two chairs would
receive the same remuneration ; but the payment would vary,
although both quantities are equally a move's work. The
wine-glass workman, (or gaffer,) one servitor, and foot-maker,
for making the sixty wine-glasses, would receive six shillings
per move, and the bottle chair only five shillings between
the three men. If, in consequence of superior skill and
industry, the chairs made double that quantity in the six hours,
which is often the case, they would be paid double the price;
and in proportion for any intermediate or lesser number, so
that the men are paid proportionally to the quantity manufactured.
The workman, or gaffer, of the castor-hole chair, in full
employ, may sometimes earn SI. per week, the second 21. 5s.,
and the third about 305. per week. Perhaps, the average earnings range from an eighth to a fourth less than these rates.
The second, or cutting chair, 21. 10s., 11. 15s., 11. 7s., for the
three grades of men; the third, or wine-glass chair, about
the same as the second; and the fourth, or phial chair, 36s.,
27s., 20s.; will be the highest rates of earning. The above

MODE OF PAYMENT, ETC.

91

estimates are based upon a calculation of full work, subject to
the decrease of from one-eighth to one-fourth, and a still
greater reduction, when work is scarce, which is not unfrequently the case.
All the above workmen are thus paid by the piece.
Four chairs of men are capable of working out nine or
ten pots of metal weekly, holding each sixteen to eighteen
hundred pounds' weight of Glass. One-third of the whole produce may be of the best and finest quality, for chandelier, or
table Glass; one third for lamp-chimney glasses, tumblers, chemical apparatus, ink-stands, roughed moons, and other articles,
not requiring to be entirely colourless, although equally as
free from specks and strise as the very best Glass; and about
the remaining third, and sometimes much more, of the common
phials or perfumery bottles. The clearest Glass is always found
in the middle of the pot. Of course, the proportion of work
will materially vary according to the nature of the demand ;
and as no manufacturer can regulate proportion, kinds, or qualities demanded, they will sometimes be in excess for the fine
goods, or for the coarse, as it may happen. The phial-makers
may be almost standing still for work, when the castor-hole
workmen have more than can be accomplished in a reasonable
time; so that the manager, although he may have plenty of
orders in the aggregate, is sometimes at a loss for such orders
as will suit the metal, or the chairs, at the moment he may
be arranging the work at each change of the move, or every
six hours. The manager is also puzzled with minor difficulties : many of the articles by the book numbers, regulating
the piece prices, remunerate the workmen indifferently, compared with other articles; he may be driven, therefore, for the

92

CURIOSITIES OF GLASS-MAKING.

execution of a large number, in a short time, of bad work, (as
it is technically termed,) which perhaps all goes to one chair;
whereas better work, at the same time, is required to be made
by other chairs, of a much more remunerative nature, which
is liable to cause a feeling of discontent and jealousy. The
manager needs a sense of strict j ustice, tact, and good humour,
to keep himself popular with his men. Decision with promptitude, founded on justice, is always respected and obeyed by
operatives, who are never insensible to the suaviter in modo,
even when accompanied by the fortiter in re. A gentlemanly,
well-educated manager is, therefore, usually most successful.
WASTE OF GLASS.

Much waste of Glass takes place in working the fused metal
into wares. The greatest waste is incurred by the wine-glass
workmen, who scarcely convert into wares one-third of the
fused Glass, although they gather from the middle of the
pot, where the metal is always most free from striae, &o. The
least waste is occasioned by the phial blowers, who use above
two-thirds of the metal they gather from the top and bottom of
the pot, where the metal is comparatively impure. The average
waste cullet, ladled, or skimmed metal, of the whole of the
chairs, is about fifty per cent., or one-half, which is chiefly
used again as cullet in the batch of the following week; but
every re-melting deteriorates the quality. The loss in broken
Glass, in small fragments on the floor of the Glass-House,
or elsewhere, is not a very material item; but profits are
often seriously reduced by loss of metal through broken pots.
The waste, or cullet, &c, is carefully collected and picked,

TUMBLER.

93

that the blacks, or parts adhering to the blowing-iron, may be
selected for inferior purposes, or for Glass of a light green
colour. Loss by waste and casualties may be estimated at
ten per cent.
Formerly, under the Excise laws, makers received a very
inadequate allowance for waste, which had to be accounted
for weekly; and at least seven and a half per cent, loss would
have accrued to the manufacturer, unless he had evaded the
law, by bringing as many casks of cullet from other parts of
the premises, or weighing as much cullet twice over, as was
necessary to make up the requisite weight. Excise officers
permitted the evasion—certainly a questionable fraud—it being
impossible to carry out the Act of Parliament, with justice to
the manufacturer, without his resorting to self-defence. These
facts were laid before Lord Goderich, then Mr. Eobinson, who
immediately passed an Act that remedied the evil which so
long had been productive of evasion and immorality, without
any security to the revenue.
TUMBLER.

One of the simplest articles to make by hand is the Tumbler;
but great attention is required in the gathering, to obtain very
clear Glass, free from stones, specks, or stride; also, after marvering, it should be well fire-polished by re-heating or melting
out the marver marks; thus removing the numerous irregular
indentations generally attributed to bad quality, but entirely
due to the carelessness of the workman. To preserve uniformity of weight, substance, and size, needs great experience
and attention.

94

CURIOSITIES OF

GLASS-MAKING.

The first and only gathering is A ;
marvered and expanded by blowing,
B ; this having been allowed by its own
gravity to drop upon the marver,
upon further blowing, it resembles
c; it is then whetted off at D ; and
the punty takes the flat end by adhesion E; which is then sheared, flashed,
thrown, and finished.
The above supposes a strong flint
best pint tumbler to weigh 16 oz.
When common light cheap tumblers are required, they
are not sheared, and no pains is taken in polishing out
the marver marks. They are ringy or wavy, and are called
tale tumblers. The barrel shape, E,
E
F
and beaker shapes, F, are but modifications of the same principle of mani
pulation.
CYLINDRICAL LAMP-GLASS.

Another simple piece of one gathering is the Lamp Chimney,
which requires pendulum and circular swinging motions to
elongate the shape. The quantity of metal being small and
light, the throw must be sharp and decided.
The first solid gathering, A, is
expanded and swung out, until it
becomes during the blowing as B.
I t receives more blowing and swinging until it is much longer, as c ; a
lump at the end is whetted^off at the

RETORT.

95

dotted line, D, and opened with
the pucellas at E, in which state,
when large, it is called a muff; a
post, or disk, is then applied at F,
that the other end may be sheared,
warmed up, and knocked off the
post. This forcible knocking-off
leaves a rough surface at one end,
which is very liable to cut or scratch the hand in cleaning. A
machine is sometimes used instead of a post; this machine
is usually a sort of spring cradle at the end of an iron rod;
which clips the chimney two to three inches from the bottom,
avoids the use of the Glass disk, and prevents the ragged
edge, but it is apt to ovalize the chimney; it is not, therefore, much used in Glass Factories. (See G.)
RETORT.

The Eetort requires much skill in making the weight
small in proportion to its size, and needs sharp swinging and
extreme care that the bent part between the quill and the
body of the neck (r>) should not
A
get too contracted, it having at
that point always a tendency to
collapse while blowing: A is the
gathering, which after being well
swung and blown, is as- B, which
is required, while being blown, to
be raised in the air, allowing the
body, by its gravity, to bend the part D over a bar. On being
further blown, it is whetted off at c.

96
BL0WN-0FF DISHES.

Blown-off (dishes, salts, &c.) is a term well known in the
trade. Nearly all dessert dishes, especially those of an oval or
square form, are made upon this principle. An oblong dish, of
ten inches long, weighs about six pounds, and requires two or
three gatherings of metal. When it has been well rolled and
flatted into a crude square or other form upon the marver, the
workman ascends the chair, and presses it into a brass mould
previously placed upon the floor; urging the pressure by
blowing, lifting it up repeatedly, and again, as it were, stamping it into the mould; and at last, increasing the inflation from
the lungs, and greatly expanding the upper part of the dish
called the blow-over, till it becomes so thin at parts as sometimes to explode. A piece of wood is used to knock off the
lower part of the overplus, leaving the dish, of considerable
substance, which is then turned out of the mould for annealing.
SCOLLOPING OR CUTTING.

The above mode of blowing-^, as (A) distinguished from
blown-over, (B) was of importance during the
Excise laws, as it prevented duty being paid
upon waste Grlass; the plan is still practised,
and with advantage. Blown-over, B, is similar
to A,but less expanded upwards; the surplusage is, therefore, thicker, and must be flown
off by the glass-cutter when cold, which incurs great risk. Whether dishes are to be
cut or only moulded, the rough edges must,
when annealed, be carefully pinched off, and
shaped by the Glass-cutting wheels, preparatory to being finished in scollops, &c.

97

HANDLED

JUG.

Next to welding rings, putting on handles is interesting to a stranger. Handled goods require very careful annealing, and the breakage often takes place at or contiguous
to the handle, although the blow may be given elsewhere;
great risk is, therefore, incurred in cutting.
For making a quart jug of four pounds weight or more,
it is necessary to gather a ball of solid glass of eight or sixteen ounces weight, as A. When it
has cooled sufficiently, (technically
called chilled,) the full quantity may
be obtained by the second dip or
gathering, which has to be marvered and blown as B ; and, after
swinging, re-warming, and shaping
with the battledore, the form somewhat approximates its ultimate
shape, c. The foot is then added
and opened, as D ; the punty iron
is next stuck to the middle of the foot, and the mouth rewarmed and sheared, as E. Again re-warming the mouth, it is
opened by the pucellas, and a piece of hollow Glass, previously
prepared, F, presses down
F
or shapes out the lip; whilst
the temperature being below welding heat, the
glasses do not adhere. The
lip or spout is then regu-

CURIOSITIES OF GLASS-MAKING.

lated with the pucellas. The whole is re-warmed and made ready
to receive the handle, which is prepared by the servitor, and consists of a long piece of solid soft Glass, A. It is allowed by its
own gravity to fall and to weld on the upper part of the neck of
the jug, B, exactly opposite the lip; great care being taken that
the part receiving the handle is free from dust, or the sulphur
which arises from burnt coal or damp wood, which would
render the adhesion incomplete.
As soon as the handle welds firmly, it should be separated
from the iron, F, sheared
through; and the workman instantly takes it
with the pucellas, c, and
throwing it a little back,
and then forward, he
slowly draws it back
again, and gently presses
the ^)ther end upon the
lower part of the heck of
thejug, D. Whenthispart
likewise adheres, the handle is shaped by rotating the jug and
distending the handle by centrifugal motion, as E. The handle
side is then turned upward, and the pucellas gives the finished
form to the handle. The jug is, lastly, warmed all over, and
placed in the lear for annealing. The adhering parts of the
handle (technically called sticking parts) need gently pressing
to assist the welding; and at each sticking operation, quick
rotation of the jug and re-warming are essential.

99

FRENCH

LAMP-SHADE.

The following is another illustration of the process of making
by hand. For many years, the trade in French Lamp-shades,
or semi-circles, has formed a large proportion of employment
for the castor-hole chair. The fitting part of the shade is
usually about ten inches, and the swell of its vase»like form,
about twelve inches, diameter: these are too large to be made
at other chairs, as they warm at the mouths of pots holding
metal, the openings of which seldom admit of articles exceeding six or eight inches. The mouth of the castor-hole pot
is about twenty-four inches, which is diminished at pleasure,
by rolls of Stourbridge clay, diminishing, circle upon circle,
until the required size of the opening is attained. The
French enlarge or lessen the opening of the castor-pot by
consecutive rings of burnt clay fitting upon each other, a
much superior and cleaner mode of effecting the same object.
A few years since, this plan was tried in our own Glassworks,
but was soon discontinued.
The footmaker takes a solid lump
s*^^
C
of Glass, A, which, after a second
—
^_^/A
gathering, will weigh about four
pounds, B. The blowing-iron is
^^===^^
stronger, thicker, and of a larger
bore, than those used by the other
chairs; and the blower, by adroitly
rubbing it on the marver, and blowing simultaneously with the rotating motion, approximates
it somewhat towards its ultimate form, c. The knob at D is

100

CURIOSITIES OF GLASS-MAKING.

knocked off, leaving a small
opening, as at E.
During the progress of the
work, at nearly every change
of form, the Glass has to be rewarmed. Afterwards, the piece
of Glass, F, is made to adhere
to a small disk; and softened by
the heat of the furnace through
the castor-hole pot, (assisted
by the heat from the flame
of small pieces of dry beech
wood,) the opening is enlarged
by the pucellas, G, and the neck
is formed, which is made to
adhere to the post, or disk, H.
The other end, I, is partly
opened by the pucellas, and
partly expanded to its ultimate shape, K, by the flashing
process : this consists of retiring it from the heat, to take
in comparatively cold air; and
afterwards advancing it towards
the heat of the castor-hole,
which, expanding by rarefaction of the air, accompanied
simultaneously with a sharp
trundling or rotatory motion,
the globe form becomes more

RINGED DECANTER.

101

or less widened, at the pleasure of the operator. The Glass
disk, L, is then released from the neck, by a dexterous tap
with the chest knife, M,* and the Lamp-shade is finished. If
the blow be too sharp, it is apt to chip the brim, and occasionally to destroy the shade. A wooden peel is used to convey the perfect article to the lear for annealing.
RINGED DECANTER.

Making a decanter is a simple operation. The gathering
is as usual, at A ; when swung out,
A the form will be as B ; upon being
further expanded, and battledored at
the end, it will be thus, c. The next
progressive operation will leave the
shape as D. The ponty iron is
placed at and adheres to the bottom, E, and the mouth is warmed up
and shaped. Another workman then
gathers upon a ponty-iron a small
D
piece of Glass, which is dropped on
to the part where the ring is required, F. By rotating
E
the decanter, the entire circle, or ring, becomes welded by con* The chest knife is a cube of steel, having four acute angles and a
handle, about twelve inches total length; it is principally used for knocking off, into the chest, the waste metal that adheres to the blower's iron,
hence technically called chest metal.

10.2

CURIOSITIES OF GLASS-MAKING.

tact, and its surplus
is tapered, and torn
suddenly away. The
whole is reheated, and
the pucellas are then pressed upon the ring of the decanter
while rotating upon the inclined plane of the chair. Pucellas
for forming rings differ from the common tools, in having two
dies affixed to the prongs; which dies, being pressed upon the
ring while hot, give the required shape and size. A second
and a third ring are then added, after reheating the decanter,
as F, by repeating the process; and by the punty affixed
to the bottom, the brim may be finished, and the rings well
melted in, to insure safe welding and annealing.
MOULDED BOTTLES.

The process of moulding common apothecaries* phials, and
the principle on which nearly all perfumery bottles, as well as
common wine-bottles, are made, cannot be more satisfactorily
explained than by the well-informed author of the article upon
Flint Glass in the work entitled " Days at the Factories'* We
first saw/' says the writer, " some four-sided perfumery bottles
made. A man took a hollow iron tube, about five feet long and
half an inch in diameter, and dipping one end into a pot of
melted Glass, collected a small quantity at the extremity. The
Glass appeared like a projecting lump of red-hot iron, and, from
its consistence (between that of treacle and of putty), was just
able to be retained on the tube. He then rolled the Glass on
a flat plate of iron, thereby giving it a cylindrical form, and
* "Days at the Factories." By George Dodd. C. Knight.

MOULDED BOTTLES.

103

pinched a part of it, by means of a small instrument, to form
the neck of the bottle. He next inserted the end of the tube
into a small brass mould lying on the ground, shut up the
two parts of which the mould consisted, and blew through the
tube. This double operation produces a curious eiFect; for
while the air from the lungs, passing through the tube, makes
the mass of Glass hollow, the mould at the same time imparts
to it the external form required. The mould being opened,
the Glass—now in the form of a bottle—was withdrawn."
The mould A, as sketched, is termed
an open and shut mould, and is generally constructed in two exact halves,
(connected with a bottom hinge,)
which in a round bottle shows two
seams or lines, caused by the two
sides of the mould not shutting quite
closely. The seam is
not unsightly in the
square form, as the
joint takes place at
two of the corners, B.
Many manufacturers prefer
moulds for round bottles, of
one piece for the body, c,
and two pieces for the neck,
(D D,) by which the seam
down the body is avoided;
although two slight seams
are observable in the neck.
E is an expanded ball of

104

CURIOSITIES OF GLASS-MAKING.

metal just entering the mould, which instantly takes its form
by sharp blowing; the brim is then finished, as before explained, by the gaffer, or workman, at the chair. This is
an expensive principle of mould making; but it decidedly
gives a more polished surface to the bottles, and produces
excellent apothecaries' phials of uniform size and capacity. The
phial cannot, however, be made of a perfect cylindrical form,
as it needs the upper part of the mould to be a slight degree
larger than the lower, to allow of the delivery of the bottle
from the mould. It is closed by a treadle acting upon two
levers with inside springs, which again open the mould when
the foot is removed.
All bottle moulds, while working, require to be kept nearly at
a red-heat, by means either of a small furnace, or a piece of hot
Glass, which is held by a lad inside the mould upon a puntyiron, during the intervals it may be unoccupied by the
two blowers. Without this precaution, the surface of the
bottles will be ruffled. The heat of the moulds is essential
to the polish; but care is requisite to keep the metal moulds,
whether brass or iron, a little below red heat, or the Glass
will adhere to them.
MOULDED ROMAN PILLARS.

Moulded Glass, as recently introduced by the English
manufacturer, owes its refractive and cut-like effect to its
inequalities of substance — the interior having no indentations to correspond with its exterior projections. It requires, in addition to the usual Glass-maker's tools, only a
metal mould of about one third the size of the object to be
manufactured. The metal is first gathered upon a rod in
the ordinary manner, except that the first gathering should be

MOULDED ROMAN PILLARS.

105

allowed to cool to a greater degree of hardness than usual;
the second coating should be pressed into the mould, A, as
hot as possible, that the exterior coating only shall be
acted upon by the pressure of
moulding, and that the interior
shall preserve its smooth circular area. When about half
formed, the projecting parts, B,
have a centrifugal enlargement given to them by a sharp
trundling of the iron at, or
immediately after, the moment
the workman is blowing; during the re-heating process, the
piece is separated at c, has a foot
welded to it, and is re-warmed,
as D; sheared, as E ; and when
finished, by flashing, shaping,
&c, as F, is called patent pillarmoulding. The fire polish is
given to it by frequently re-melting the surface of the Glass, after
it leaves the mould. A little
cutting or scolloping makes this
refractive moulding still more
ornamental; but, though it
much resembles cutting, (as to
its round pillars), it is inferior
where sharp angles are required.
p

106

CURIOSITIES OF GLASS-MAKING.

Pillar moulding is, however, one of the greatest modern
improvements; and is used advantageously for lamp pedestals,
chandelier work, toilet bottles, salt-cellars, &c, at very
moderate cost. This was supposed to be a modern invention,
and introduced by the late Mr. James Green, as such, a few
years since; but, in some Eoman specimens, recently exhumed
in the city of London, and now in the possession of Mr. Roach
Smith, it is proved beyond doubt that these projecting pillars,
and the mode of their manipulation, were well known to the
ancients. (See coloured Plate 3, fig. 2.)
CANE AND TUBE DRAWING.

The ductility of Flint Glass is strikingly exhibited in the
process of Cane or Tube-drawing, which is extremely simple,
and depends so much upon tact and adroitness, that it is a
matter of surprise how an approximation to uniformity of size
and bore can be attained. A solid ball being gathered on the
end of the blower's iron, A,
if for hollow tube, is expanded
a little by blowing, B ; but if —
for cane, blowing is not requisite : when partially cooled,
it forms a nucleus for one or
more other gatherings, until
the requisite quantity be obtained. Where flat bore tube
is required for thermometers, the first ball is flattened by an
iron or wood battledore, on the marver, prior to the subsequent gatherings; this ensures a flat bore, although the exterior of the tube is round. The ball is then elongated by

CANE AND TUBE DRAWING.

107

swinging, c, and the further end of it is chilled by dipping
it into cold water. A workman then, having prepared a disk
of hot Glass, D, called a post, places it vertically as near the
ground as possible, to receive the ball from the chief workman;
he next ascends his chair, or an elevation, so that the hot Glass
may by its gravity be dropped upon the post below, to which
it adheres by partial welding, E. The chief workman then
E

descends from his elevation ; the drawing now begins—each
workman constantly receding from the other: at first, the suspended Glass between the two rods assumes (at a red heat)
the form of a parabola, F ; but, as the tension proceeds, the

workmen are continually rotating. Some parts are cooled by
fanning with the hat of an attendant boy, to ensure uniform
elongation, till the cane or tube is drawn to a length, sometimes of from sixty to seventy feet: as the metal cools, the
tube ceases to rotate, and it assumes, by continued tension,
nearly a straight line, G; except at the extreme ends, it is

108

CURIOSITIES OF GLASS-MAKING.

nearly of one uniform bore, diameter, and substance; and
whatever may be the diameter of the tube, the bore and substance will always bear an exact relative ratio to each other.
Lastly, it is deposited upon the wood rounds of a ladder, and
requisite lengths are whetted off by the cold iron, or by a steel
file.
VENETIAN FILIGREE GLASS.

As Glass-house manipulators, the Venetians were preeminent; they produced, if not the most elegant, at least extremely curious, work. In the manufacture of Glass beads, the
Venetians have no rival, their price being far below English
competition. The Venetian glasses, termed " filigree," have
recently been made in France and Bohemia, and a few specimens in England. Before ornaments or vessels can be
blown, small filigree canes* with white or variously coloured
enamels, must be drawn by the following process:—Pieces of
plain, coloured, or opaque white cane, previously drawn as
explained above, are first whetted off to the required lengths,

* " Cane" invariably means a solid stick of Glass ; and " tube," hollow.

VENETIAN BALL.

109

H, and then put into a cylindrical mould, I, with suitable internal recesses; and both cane and mould are thus submitted
to a moderate heat. The selection of the colour of the canes
depends upon the taste of the manufacturer: two to four
white enamelled canes are chiefly used, alternately, with about
half the number of coloured. The blower then prepares
a solid ball of transparent flint Glass, K, which being deposited
in contact with the various canes, at a welding heat, causes
them to adhere. This solid ball is then released from the
mould, as L, is reheated, and marvered, till the adhering projecting ornamental canes are rubbed into one uniform mass;
the ball is next covered with a gathering of white glass, which
must then be drawn to any size and length that may be required, by the same process as before described and illustrated.
Should a spiral cane be preferred, the pucellas holds the
apex, M, in a fixed position, while the ornamental mass, still
adhering to the Glass-maker's iron, is revolved during the
drawing, till the requisite twist is given. Where vases are
formed of alternately coloured and enamel filigree canes, the
above process is repeated, and the usual mode of blowing and
manufacturing is followed; but the ball, K, must be hollow
instead of solid, so that the filigree canes become, by marvering, &c, amalgamated with the flint Glass ball, and expand
with it in its progress of manufacture.
VENETIAN BALL.

The Venetian ball is a collection of waste pieces of filigree
Glass conglomerated together, without regular design : this is
packed into a pocket of transparent Glass, which is adhesively
collapsed upon the interior mass by sucking up, producing out-

110

CURIOSITIES OF GLASS-MAKING.

ward pressure of the atmosphere. Some of the ancient specimens have apparently been decomposed on the exterior,
but can be again restored by the Glass cutter's polishing
wheels. (See Plate VI., fig. 1.)
MILLE-FIORE.

The Mille-Fiore, or star-work of the Venetians is more
regular in design than the ball, but of the same character.
It was formed by placing lozenges of glass, cut from the ends
of coloured filigree canes, ranging them in regular or irregular devices, and encasing
them in Flint transparent Glass.
The double transparent Glass
cone, A, receives the lozenges
between the two surfaces. The
whole is reheated; a hollow
disk, communicating with the
blowing-iron, adheres to the
neck,B, and the air is exhausted
or sucked out of the double case, as further explained in the
cameo illustration. After being rewarmed, it becomes one
homogeneous mass, and can be shaped into a tazza, paperweight, &c, at pleasure.
MOSAIC WORK.

The Eomans, and possibly the Greeks, formed beautiful
arabesque and other designs of Mosaic Glass: many of these are
of minute and accurate execution, in light colours beautifully
harmonized upon a dark ground, formed wholly of threads of
Glass. They are ranged vertically, side by side, in single threads

MOSAIC WORK.

Ill

or masses, agreeably to a pre^5*W1H3HS llnn!£i8#fllflliHl^Klmfti^
figured design. When submitted to heat sufficient to
fuse the whole, the four sides,
at the same time, being pressed
together, so as to exclude the
air from the interstices of the threads—the result will be a
homogeneous thick slab, which, if cut into veneers, at right
angles or laterally, will yield a number of slabs or layers of
the same uniform design; these, it is supposed, were employed
by the ancients in jewellery ornaments. Many specimens
may be seen in the British Museum. (See coloured Plate III.,
figs. 5, 6, 7, and 8.) On this principle were executed the
pictures of Mosaic Glass noticed by Winckelmann. Ancient
pavements were inlaid with small pieces of coloured Glass,
some quite opaque, of various tints, put together with
cement, in a like manner to the fictile, tesselated pavements.
Similarly small pieces of opaque enamel and Glass were also
used in great abundance to ornament the fountains of Pompeii ; and specimens of this class are continually discovered.
This tesselated Glass-work is, however, entirely dissimilar to
the above Mosaic, the various pieces not being, as in that,
homogeneously united together by fusion. Minutoli, in his
" Farbigen Glaer beiden Alten/' gives a drawing of three
nymphs and a male figure, the latter carrying a water-urn, and
the three former wearing coronets of reeds, all in tesselated
light green Glass, whilst the entire of the dark green background and yellow figures of the picture, are executed in
stone mosaics.

112

VENETIAN

DIAMOND-MOULDED.

The old Venetian Diamond was formed
by impressing soft glass in a metal mould,
as follows:—the first gathering, A, is
solid, and afterwards covered by a second
gathering, as B ; this is expanded by blowing in the usual manner, and being rewarmed, is blown into the projecting pillar-mould, c, and when further expanded,
impresses the Glass ball as D ; the pillars
are pinched together by the pucellas, E,
at equidistant points, into the diamond
form, E and F, one by one, until the whole
of the projecting straight pillars become
diamond pillars. Equally good effects
are produced by modern Glass-makers
in a more direct manner, by making brass
open-and-shut, or dip moulds, so as to
give at one operation the entire diamond
impression, thus saving the tedium of
forming each diamond separately with
the pucellas. Some of the old Venetian
caraffes, with handles and loose stoppers,
have Glass ornaments laid in lines vertically upon the diamonds, pinched and
raised up in parts, in uniform patterns,
perhaps more illustrative of industry than
taste.

113
VENETIAN VITRO D I TRINO.

The solid ball
being gathered,
as A, expanded
by blowing, and
marvered, as B,
&c.; the interstices of the interior of the mould
of brass, agreeably to the section
annexed, c, are
filled with small
white
enamel
canes; and the
ball of Flint Glass
is then blown fully up to the canes,
to which it firmly welds, as D.
As soon as it has
been re-warmed,
a workman holds
with the pucellas
the bottom of the
ball, D, while another workman
twists the blowing-iron, giving
the conical form,

114

CURIOSITIES OF GLASS-MAKING.

as sketched in E ; it is further whetted off at F, opened, as G,
and has the projecting canes on the outside of the cup; a Glass
disk, or post, being made to adhere to its open end, as H. The
inner case of the Vitro cli Trino process is thus completed.
To make a corresponding outer case, a ball must be formed
into a cup or cover, of exactly the same character, a little larger,
but turned inside out, as i; which gives the twist the reverse
way, and causes its interior canes to project inside the cup, K.
The inner cup, or case, H, is now placed within the outer
case, K; and these two conical cases now crossing each
other, are, by re-warming, collapsed together, entrapping between each white enamel crossed section, uniform interior
air-bubbles, as L ; and the two cases, now become one, may
be formed into the bowl of a wine-glass, or any other vessel;
the disk, H, having been previously removed by a gentle tap
of the chest-knife. Upon this principle was made the specimen, in the coloured Plate 4, fig. 1.
CASED GLASS.

The principle of casing a layer of colour upon Hint Crystal
Glass, or as many layers or varieties of colour upon each other
as may be required, was well known to the ancients who made
the Portland and Naples Vases. Only one operation need
be explained, as every additional coating is merely a repetition of the same process. Presuming, therefore, that any two
or more glasses intended for casing have been mixed of the
same specific gravity, to give them the capability of harmonizing,—that is, contracting and expanding equally,—the
blower has to gather a ball of solid Glass, intended for the
interior layer, in the usual manner, as A, which, in this instance,

CASED GLASS.

LIS

may be considered to be of white crystal Glass. About the
same time, his assistant prepares a casing of colour, B, knocking off the knob at c, to open and shape it, as D, somewhat
like the bowl of a wine-glass, or the broad-end of a large
egg-shell; this is set into a metal stand, E, on the floor,
merely to steady the case, or shell, B ; while the blower takes
the lump of Flint or white Glass, A, and gently blows it

into the coloured case, or shell, B, to which it immediately
adheres; and when submitted to the flame of a pot-hole,
or, if a large piece, to the flame of the castor-hole, it is
found to "weld perfectly, as F. If various coverings are
needed, as many coloured shells must be prepared as required, and each time melted in by fresh warming, until the
entire number are obtained and cased. The whole are afterwards rewarmed, expanded, and shaped into vases, tazzas,
or such other articles as the manufacturer requires, by blowing, and the usual appliances of moulds, tools, rotatory motion,
&c, as have been explained in former manipulations. If cased
coloured Glass for windows be made, the cased ball must be
larger, expanded, elongated, and made into a cylinder, or muf£
precisely as in optic plate, or a lamp-glass; but in large sheets,
after shearing through the whole length of the cylinders, and

116

CURIOSITIES OF GLASS-MAKING.

flatting them into square panes, in a kiln provided and heated
for the purpose.
OLD VENETIAN FROSTED GLASS.

A, is the first gathering; B,
the second, expanded by blowing; while at nearly a white heat,
it is suddenly plunged into
cold water; if immediately re1
B
warmed and blown, the effect
will be as c; flatten the bottom,
and whet off at D ; attach a
ponty, as E, and finish the
article as usual; bat in the
latter process, the less heat the
better, or it will melt out the
frosting.
Frosted Glass, like the Vitro
di Trino, is one of the few
specimens of Venetian work
not previously made by the
Egyptians and Romans; and
not since executed by Bohemian
or French Glass-makers. The
process of making it, until recently practised at the Falcon Glass Works, was considered
a lost art. It has irregularly veined, marble-like projecting
dislocations, with intervening fissures. Suddenly plunging
hot glass into cold water, produces crystalline convex fractures, with a polished exterior, like Derbyshire spar; bat the
concave intervening fissures are caused, first by chilling and

WELDED COLOURED GLASS.

117

then reheating at the furnace, and simultaneously expanding
the reheated ball of Glass by blowing; thus separating the
crystals from each other, and leaving open fissures between,
which is done preparatory to forming vases or ornaments.
Although frosted Glass appears covered with fractures, it
is perfectly sonorous.
WELDED COLOURED GLASS.

Welding coloured Glass to white or lighter-tinted Glass,
for windows, skylights, &c, has been patented by the author.
It is effected with detached pieces of dark-coloured Glass
prepared by cutting, pinching, or moulding; these are placed
in the interstices of cast brass, or iron moulds, previously
chased by the die-sinker; and the whole are gradually
heated to nearly a red heat. Hot white, or light-tinted Glass,
is then cast upon the mould, about the consistency of honey;
the entire mould is covered with it, and rubbed with wood, till
cold enough for annealing; when it will be found firmly welded
to the detached coloured pieces, and will deliver from the
mould as one entire mass. Should one uniform tint only
be required, the detached coloured pieces are dispensed with;
and the rolling or pressing is the same with one colour as
with the above various tints; the light and shade beingproduced, where one colour only is used, by the unequal
substances of the tinted Glass having a tendency, in the
thickest portions, to exhibit complementary colour.* This
* Eosettes for windows may be pressed at a very reduced price by this
process. Mr. Eastlake, Secretary to the House of Lords' Commission,
allowed several specimens made at the Falcon Glass Works to be exhibited
in St. James's-street, at the first public display of works of art in connexion with the Commission.

118

CURIOSITIES OF GLASS-MAKING.

principle was first explained by Professor Cowper, of King's
College, London.
CRYSTALLO ENGRAVING.

In addition to Cameo Incrustation which was patented
many years since, a subsequent patent was secured for taking
fac-similes of casts or dies from intaglios, and impressing
them upon hollow Glass vessels in intaglio. This plan of Glass
engraving has been chiefly adopted where numerous copies
of elaborate devices have been required; such as badges of
regiments, or arms upon decanters and table Glass. The following is the mode of operating: dust Tripoli, very finely pulverized upon the die or cast; then a larger coating of dry plaster
of Paris and pulverized brick-dust, with another layer of coarser
plaster of Paris and brick-dust; place the whole under a press,
which when screwed to its utmost, allows water to saturate

[The above represents the workman fitting the cold, dried, Tripoli-faced
plaster cake, into the recess of the mould, as it occasionally requires a little
reducing with a file. I t is afterwards removed, and brought to a red heat
in a small muffle set in the furnace, and placed in the heated brass mould
with a pair of iron tongs.]

CAMEO

INCRUSTATION.

119

the pores of the impressed cake; and, when gradually dried, it
will be fit for use. A brass mould, A, with a recess to receive the
cake, and a hinged leverage to keep it in its position, B, is
provided; so that the face of the cake, c, which is then embossed
in relief, ranges with the circular form of the Glass vessel
intended to be blown into it; and this, being heated to redness,
is placed in the recess of the mould. In this state, the ball
of hot Glass is introduced and expanded by the power of
blowing, till it assumes the exact shape of the mould, and the
cake adheres to the Glass. The cake is then released by the
lever, and the Glass reheated, with the cake adhering to it, as
often as necessary to finish the article, (as usually practised by
blowers in ordinary moulded Glass vessels); the cake and Glass
vessel being annealed together, with its blow-over, which is
afterwards finished by the Glass-cutter. When the Glass is
cold, it is released from the cake by its absorption of cold
water, and the intaglio impression upon the Glass will be
found as sharp as the original die. A cake once used, seldom
answers for a second impression. Mr. Tassie had, long before
this process was patented, executed on the same principle imitations of small gems in solid Glass, very successfully, which
suggested the application of the same invention to hollow
vessels.
CAMEO

INCRUSTATION.

Cameo Incrustation was unknown to the ancients, and was
first introduced by the Bohemians, probably about a century
since; and Bas-relief casts of busts, and medals, were entirely
isolated by them within a coating or mass of white Flint Glass.
The figure intended for incrustation must be made of materials
that will require a higher degree of heat for their fusion than
the Glass within which it is to be incrusted; these are china

120

CURIOSITIES OF

GLASS-MAKING.

clay and super-silicate of potash,* ground and mixed in such
proportions as upon experiment harmonize with the density
of the Glass; and this, when moulded into abas-relief or bust,
(in plaster of Paris moulds,) should be slightly baked, and then
suffered gradually to cool; or the cameos may be kept in readiness till required for incrustation, for which purpose they should
be carefully reheated to redness in a small Stourbridge clay
muffle. A cylindrical flint Glass pocket is then prepared, one
end adhering to the
hollow iron rod, M, with
an opening at the other
extremity, into which
the hot composition
figure is introduced; the
end, N, is then collapsed
and welded together by
pressure, at a red heat,
so that the figure is in
the centre of the hollow hot Glass pocket
or muffle. The workman next applies his mouth at the end of the tube, o, while
rewarming the glass at the other extremity; but instead of
blowing, he exhausts the air, thus perfecting the collapse, by
atmospheric pressure,, and causing the Glass and composition
figure to be of one homogeneous mass, as p.
Small bas-reliefs and casts of coins or medals are incrusted
in a more expeditious manner, and especially upon hollow
* By super-silicate of potash is meant, sand exposed at a high temperature in a crucible, with a small portion of carbonate of potash, sufficient
to fuse it partially, for grinding into an impalpable powder.

AMERICAN P R E S S E D

GLASS.

121

Glass vessels, by placing a hot prepared cameo, of the usual
composition, upon the hot manufactured vessel; a small piece
of liquid Glass is dropped on it, and becomes welded; and,
if rubbed while hot, the upper coat of fused Glass will be
spread as thinly as possible upon and around the cameo,
behind which are driven any air bubbles that may be entrapped; thus completely isolating the device between the two
Glasses, These incrustations require very careful annealing.
AMERICAN P R E S S E D

GLASS.

Pressing is a mechanical operation, unknown to the

Pressing Glass.
R

122

CURIOSITIES OF GLASS-MAKING.

ancients or the Venetians.* It may be thus described:—a
die being prepared, secured by the ring and handle, A, metal
is gathered and dropped into it, B, and the matrix, or plunger,
c, operated upon by the lever, &c. D, presses the metal into
the required form of the article. If an overplus of metal be
gathered, it thickens the article throughout; but if too little,
it fails to fill up the mould, and is spoiled. This is a rapid
mode of reproduction, but great practice is required to gather
the exact quantity of metal. The chief condition of success,
in getting a polished surface on pressed Glass, depends upon
the moulds being kept at a regular temperature, a little short
of red heat. The effect is not so good as pillar-moulding, nor
does it anneal so well; but it is much less expensive. The
interior plungers and the outer die will adhere to the Glass if
too hot; and if not at a proper temperature, will fail in producing a clear transparent surface.
DROP PINCHING.

Pinching by moulds is chiefly used for solid drop-work,
spangles, &c. Lumps of Glass made expressly for drop
pinching, f when softened sufficiently by a blast-furnace, A,
are shaped in twin brass dies, affixed to tongues, B. Arms of
chandeliers are pressed also by twin dies, the upper die being
fixed to the plunger, and the under one to the bed of a
* Various slabs of coloured Glass, of small sizes, were pressed into
metallic dies by the ancients, as proved by the specimens of embossed and
intagliated Glass, of various patterns, in the British Museum; hut no
machinery was used by them in producing any completely pressed hollow
vessel or utensil, at one operation.
•j* A considerable number of the Glass drops used for chandeliers, girandoles, and candlesticks, in England, are pinched from thick tumbler bottoms, or waste glass, causing a variety of tint, and inferior refraction.

DROP PINCHING AND GLASS CUTTING.

123

powerful leverage press; the metal being gathered as usual,
and the power of the press applied. Both arms and drops
receive only the crude form; they afterwards require cutting,
and polishing on a lead lap, to produce the required brilliancy.

GLASS-CUTTING.

Glass-cutting, or, more properly Glass grinding, as illustrated in the next page, is too well known to need minute
description. A cast-iron wheel has sand and water dropping
from the hopper, while revolving in a lathe propelled by steam
power; the friction of the grit of the sand, reduces to its
required form the Glass placed beneath it. A stone wheel
with water smoothes out the rough sand marks, and prepares

124

CURIOSITIES OF GLASS-MAKING.

it for the polishing, which is effected by means of a willow wood
wheel, first with a mixture of pummice and rotten stone, and
finished by the same wood wheel, or lap, with putty-powder.*

Glass Gutting, as practised in factories where steam power is u s e d ; t h e d r u m , P ,
"being connected b y a strap to t h e engine, and communicating t h e power to
t h e smaller gear

* A preparation of tin and lead.

GLASS ENGRAVING.

125

All table Glass ware and hollow articles are thus cut; chandelier drops are also similarly cut, with iron and stone
wheels, except the polishing, which is done with a lead
wheel, or lap, supplied with a little very fine rotten-stone and
water. The sides of the lead lap are occasionally roughed,
or notched, like a file, to enable its recesses to hold the above.
When the sides become smooth by use, they must be renotched, like millstones for grinding flour.
The steam-engine has almost excluded hand labour for
turning cutters' lathes.
GLASS ENGRAVING.

The period when the art of engraving Glass borders and arabesques was first practised, cannot be satisfactorily ascertained.
Intaglio and cameo figure
engraving, upon real and
artificial stone, is known
to have been employed
by the Greeks and Romans at a very early
period, (prior to the
Christian era;) their
artists wrought and studied in the purest and
highest range of statuary
engraving; and it is probable that the bas-relief
figures on the Portland
and Naples Vases were
engraved at the lathe by

126

CURIOSITIES OF GLASS-MAKING.

these artists. The Venetians are not supposed to have cultivated the art of engraving rough ground with polished relief
on Glass, which is now, and has been, for perhaps two centuries, so successfully pursued by the Bohemians. Their
excellent arabesque borders, animals, and landscapes, are executed in quantities, with surprising rapidity, and at a low
rate of wages; from ten to fifteen shillings a-week being in
Bohemia a fair remuneration even for a tolerably artistic
engraver, who would earn fifty shillings a-week if working in
London.
Copper wheels, and finely pulverized emery mixed with oil,
are used to execute the outline and ground of the modern engraver's work; and for the polished work, lead wheels, and very
finely pulverized emery, are employed.* The most elaborate
and splendidly executed artistic specimen of engraving, is now
at the Falcon Glass works, and is the work of. a German artist,
who devoted several years to its accurate details. The subject
is from the picture of Lebrun, representing the final battle
and triumph of Alexander the Great over Darius, which ended
in the entire overthrow of the Persian empire.
Coarse patterns for hall lamps are engraved by the Glasscutter's .smoothing wheel. The contrast of the polish of a
wood wheel upon a ground roughed by sand is often effective,
though the range of pattern is somewhat curtailed by the large
size of the cutter's wheels, rendering it difficult to execute curvilinear designs. The Venetians practised a curious art of engraving with the point of a diamond, or broken steel file. This
* Stoppering, (bottles,) like engraving, requires little power, but that
the velocity be varied ; hence, the foot lathe answers as well as, or better
than, steam power.

GLASS STOPPERING.

127

simple process was, no doubt, employed anterior to engraving
by the lathe; to this it probably gave way, as the accurate
artistic effects of the lathe far surpass the crude work of
steel or diamond etching. Etching by fluoric acid has been
introduced, but its bite is not sufficiently rough, and is not
found effective for general purposes. Pleasing effects are produced by engraving through an outer casing of coloured Glass
into an interior white, transparent, or enamelled Glass, usually
afterwards decorated with gold, and painted in arabesques,
or other patterns. This work is chiefly the produce of
Bohemia, Bavaria, and France : it has recently been executed
at the Falcon Glass Works with success, in engraved classical
designs.
GLASS STOPPERING.

Stoppering is usually done within Flint Glass premises.
The lathe is similar to that employed by Glass engravers,
being what is termed a mandril tool. The mouths of the
bottles are opened by a steel projecting cone, or mandril, to
the required size to suit the stopper; and emery powder and
water being applied, the rotating friction soon effects its
object. The stopper must be fixed in a wooden chuck, and
rotated by the lathe, to be first reduced to the dimensions of
the mouth of the bottle, by emery and water; and finally introduced into it, carefully grinding the one into the other, reducing the speed, and supplying by degrees finer and finer
emery (and water), until the stoppering by the lathe is completed ; a few turns of the stopper with the hand follow to
finish.

128
GENERAL OBSERVATIONS.

To an observant eye, the working movements of the Flint
Glass-blower are performed with ease and elegance, perfectly
natural. In modern Glass-houses, which convey the smoke
instantly upward, without its descending into the houses to
affect blowers' lungs, the employment is by no means injurious to health. In the exercise of walking, swinging, and
shaping, and in almost all the manipulations of the factory,
every limb and muscle is brought into healthful movement ;
and it is found that even the exertion of the lungs in blowing
is by no means unfavourable to longevity. Much improvement has, within the last few years, taken place in the temperance and morals of the workmen. Kheumatism and gout,
which formerly prevailed among the men in Glass-works, are
not, at present, more frequent than the average experience of
what may be considered the most healthful manufacturing
employments in large towns.
In making new shapes in Glass, much is left to the judgment of the workman, who reasons and reflects on the
best mode of arriving at certain results, by avoiding toolmarks, in forming, re-shaping, &c, by which time will
be saved, and the product less disfigured. Many visitors
have been struck by the beauty of outline so frequently
developed in blowing and forming Glass vessels in their onward progress; which, although it cannot be arrested in its
rapid transition from one form to another, often suggests
new ideas or the invention of new designs. Occasionally, in
flashing, or in modifications of the flashing process, the
changes of form seem almost miraculous, and rather to be

GENERAL

OBSERVATIONS.

129

deserving of the term "creation " than that of "manipulation."
Many workmen never rise higher than the first or second grade;
and those who have taken the highest rank have shown very
early precocity. Boys commence as takers-in at about eight years
of age, and advance to the highest grade by degrees, if clever or
industrious. Unless they have learned to read and write before
that period, (their evenings being employed in the factory on
the first four days of the week,) it is only on the Sunday and
the latter part of the week that they can devote any time to
mental improvement. A school on the premises, for instruction on Fridays and Saturdays, is a great desideratum for the
boys as well as men, who wish thus to employ a portion of
their leisure time; and the expense to proprietors would be
amply repaid by the subsequent gratitude, and improved intelligence and conduct of their workmen.
Perhaps, there is no employment so much dependent upon
steadiness of nerve, self-possession, and skilful manipulation,
as Glass-making. It requires adroit adaptations of the
simplest tools, for the rapid production of manifold forms and
designs, upon the most pliant of material, while it retains
its heat; and perfection depends not altogether upon longcontinued practice, but upon a certain innate tact, without
which no workman can ever rise to eminence. There can
scarcely be, chemically, and in reference to the preparation of
the crude materials, a manufacture of greater simplicity or of
easier management than Flint Glass; but, like the delicate
machinery of the watch, or the skilful management of a
musical instrument, no small practical experience is needed
to keep everything in time and tune, and in its place, for
working out the harmonious arrangements of the whole, and
s

130

CURIOSITIES OF GLASS-MAKING.

for bringing to perfection a manufacture, which, in the aggregate, produces employment for a large number of workmen,
at a comparatively small cost of crude material.
To conclude: the invention of Glass-making has not been
more beautifully illustrated than in the following reflections,
of philosophical eloquence, from the pen of Dr. Johnson :—
" It might contribute to dispose us to a kinder regard for
the labours of one another, if we were to consider from what
unpromising beginnings the most useful productions of art
have probably arisen. Who, when he first saw the sand or
ashes, by a casual intenseness of heat, melted into a metalline
form, rugged with excrescences and clouded with impurities,
would have imagined that, in this shapeless lump, lay concealed so many conveniences of life as would, in time, constitute a great part of the ha23piness of the world ? Yet, by
some such fortuitous liquefaction was mankind taught to procure a body, at once, in a high degree, solid and transparent;
which might admit the light of the sun, and exclude the violence of the wind; which might extend the sight of the philosopher to new ranges of existence, and charm him, at one
time, with the unbounded extent of material creation, and at
another, with the endless subordination of animal life; and,
what is of yet more importance, might supply the decays of
nature, and succour old age with subsidiary sight. Thus was
the first artificer in Glass employed, though without his knowledge or expectation. He was facilitating and prolonging the
enjoyment of light, enlarging the avenues of science, and conferring the highest and most lasting pleasures; he was enabling
the student to contemplate nature, and the beauty to behold
herself."

131

EXPLANATION OF THE COLOURED PLATES.

PLATE I.
NAPLES VASE.—(Frontispiece.}

THE drawing of the Naples (or Pompeii) vase, is half the size
of the original, deposited in the Public Museum at Naples.
It was discovered in a sepulchre of Pompeii, on the 29th of
December, 1839. It is of the same character, in the colours
and quality of the Glass, as the Portland vase, in the British
Museum; the white enamel figures upon the dark blue transparent ground being raised, or embossed out of the white
exterior coating, by first-rate engravers, probably Grecian
artists working in Rome at an early period, or possibly as late
as the reign of Trajan, about seventy years after the Christian
era.
This beautiful vase is, no doubt, of more recent date than
the Portland, and has an artistic playfulness of subject, of less
severe and conventional character. It is tastefully descriptive of the in-gathering of the vintage harvest; beautifully
harmonizing the Bacchanalian figures with the arabesque

132

CURIOSITIES OF GLASS-MAKING.

scrolls. The design and execution are only surpassed by the
Portland vase, which Zahn, in his beautiful work, entitled
" Ornamentum zu Pompeii," admits to be superior. The form
is entirely dissimilar to the Portland vase, although perhaps
not less elegant. The foot of the Naples vase has been abstracted
by some sacrilegious hands. Zahn supposes it to have been
of gold. With this exception, the body of the vase, handles,
&c, indeed, the whole, is perfect; and affords a practical and
instructive illustration of the great artistic skill attained and the
time bestowed by the ancients upon this extraordinary class of
productions. It is somewhat unusual, as in the case of this
vase, to find the chief subjects—viz., the Bacchanalian figures
—placed under each of the handles, instead of between the
handles. Who is to say that the great Phidias, or his pupils,
might not have condescended to work upon such magnificent
gems of art ?
By reference to the illustrated manipulatory portion of this
work, full explanation will be found of the mode of casing, or
placing two or more coats of glass upon each other; a degree
of perfection of the art at that early period, of which the
Naples and Portland vases, and that found a few years since
at Pompeii, and drawn by Minutoli, (a portion of which is in
possession of Mr. Eichardson Aldjo, and the remainder in the
British Museum,) are splendid specimens. They are indicative
of great Glass-making skill, especially the handles, which
are shaped with admirable taste and accuracy; and we are
at a loss which most to admire—the beauty of the form, or the
skill and patience of the engraver.

PLATE

2.

*SB*Si*
.

ft

Ancient Glass found m Egyptian Tombs, at Thebes.

UfON THC 8ITC OF THt CRAND STOREHOUSE.
DEgmOTEDBTFIItEOXTBE M*OCTOBKR.in>CCCXU.
THIS FIRST 8TONC OF THE WATERLOO BARRACK.
WAS LAID » T
F O O D MARSHAL H18 GRACE THE DURE OFlTEUIVOT01Ut.G.C.C.B.CjC.R .
OOK8UBLE OF THE TOWEK OF LOHIKW U(0 COMHAWIBR W CWKF OF H.X.FflRCE«
IN THE MONTR OF JUNE MDCCOCET,
AND IK THE EIOHTH YEAH 0 7 THE HE1VH OF
HER M A J E S T Y QUEEN V I C T O R I A .
MAV 0 0 0 . OUR PRESERVER.WARD OfF 0E8TRU0TION FROM THIS 8UIUMM

Glaiss Brick in foundation stone at the Tower of London.

EXPLANATION OF THE COLOURED PLATES.

138

PLATE II.
THEBES

FRAGMENTS.

The specimens drawn in this Plate were brought by Mr.
Bankes from the Egyptian tombs at Thebes, about twenty-five
years since, and were placed in the hands of the author.
They are drawn the exact sizes and colours of the originals;
and their great variety of subjects portrays the chemical and
inventive powers of the ancients. The colours iare rich of
their kinds, and show considerable knowledge of vitreous
colouring; they are, no doubt, the produce of the earliest of
the Egyptian manufactories. It is said the great Hermes
taught the Glassmakers of Egypt this ingenious art.
Eig. 1. Is a fragment of Glass, which, when discovered,
appeared to be one piece only; but proved, upon closer inspection, to be in two pieces, adhering to each other by a bituminous cement. The variegated portion consists of well-contrasted, brilliantly-coloured devices of blue, green, red, and
yellow ; and this being attached to an adhering piece of more
subdued colours, forms a lateral continuous border, giving
to the whole a finished margin: it was probably used for
ornamenting an ancient bath. The pattern and colours
are the same on both sides; the front only was flattened
and polished, the reverse was irregular in surface, and was,
therefore, better calculated to adhere to the cement, which
not only fastened the two pieces together, but fixed them
to the walls which they decorated. In this fragment, very

134

CURIOSITIES OF

GLASS-MAKING

little decomposition is apparent on the upper surface; and
under the cement, no decomposition whatever has taken place.
Fig. 2. Has the same variety of colours as the above, but
with a regularly foliated rosette-like design, in yellow, red, and
white, upon a dark blue ground. This has a mosaic granular
appearance, and shows its pattern in front and reverse, in
an oblique direction. The acute angular fracture on the
edge, exhibits a partial section of the pattern and colours,
and leaves no doubt of the whole being formed by threads of
coloured Glasses, fused together in masses and veneered, by
cutting through at right angles, or obliquely, as more fully
explained in the manipulatory portion of this work.
Fig. 3. This fragment, a miniature effigy of the Egyptian
idol Isis, appears to have been pressed into a metal mould
while the Glass was soft. The colour was of the richest azure
blue, tolerably transparent. (See Klaproth's analysis, which
defines its chemical constituents; the colouring oxide was,
no doubt, iron.) This specimen, the production of Alexandrian, or very ancient, furnaces, was most probably suspended
about the person of its owner by the perforated loop at the
top, and worn as an amulet.
Fig. 4. A small lachrymatory vase, of the same rich azure
blue as the Isis fragment; the handle and mouth of the
vessel are crudely formed, and the white enamel on its
body is welded to the blue, and may have had some hieroglyphical meaning. It is as perfect as originally manufactured, with the exception of a very slight decomposition of
surface.
Fig. 5. Fragment of an Ethiopian effigy, or statuette, of a
clear amber colour. Its colouring constituent was probably
iron, in a different proportion of oxygen to that of the azure blue.

EXPLANATION OF THE COLOURED PLATES.

135

Fig. 6. Fragment of black pipe beads, intermixed with a
pattern of white enamel.
Figs. 8 to 15. Eight beads, decidedly some of the Aggry
beads so well described by Bowditch, and quoted in the Historical Notices of this work. (See page 10.) These have never
been imitated by the Venetians, who mentioned to Mr. Bankes
that they were unacquainted with the mode of making them.
With some practice they could, no doubt, be successfully
imitated.
Figs. 16 to 19. Specimens of ancient glass coins with inscriptions. 17 and 19 are partially opalized by phosphate of
lime (bones.) 18. The red is the effect of cojDper and iron, and
the blue, Fig. 16, of iron. (See Klaproth's analysis, page 76.)
Fig. 21. Is a specimen of modern incrusted inscription: the
letters are drawn upon a piece of glass with a vitrified black
paint, and burnt i n : it is introduced while at nearly a reel
heat, into a glass pocket, as more particularly explained in
the third portion of this work, elucidatory of the introduction
of cameo figures into Glass. (Seepage 120.) The following
is a copy of the inscription, which was incrusted at the Falcon
Glass Works:—
UPON THE SITE OF THE GRAND STOREHOUSE,
DESTROYED BY FIRE ON THE 31.ST OCTOBER, MDCCCXLI.

THE EIEST STONE OF THE WATERLOO BAEEACK
WAS LAID BY

F I E L D MARSHAL HIS GRACE THE DUKE OF WELLINGTON,
K.G., G.C.B., G.C.H.,
CONSTABLE OF THE TOWER OF LONDON, AND COMMANDER-IN-CHIEF OF H.M. FORCES,
I N T H E M O N T H O F J U N E , MDCCCXLV.
AND

IN

THE

EIGHTH

YEAR

OF

THE

REIGN

OF

HER MAJESTY QUEEN VICTORIA,
MAY GOD, OUR PRESERVER, WARD OFF DESTRUCTION FROM THIS BUILDING.

136

C U R I O S I T I E S OF GLASS-MAKING.

PLATE III.
ROMAN

FRAGMENTS.

Eig. 1. An ancient Eoman fragment of Glass of the smeltz
character. It was exhumed in the city of London, near Moorfields, and is now possessed by Mr. Koach Smith: it is a
melange of yellowish-white enamel, with a very dark iron red.
Specific gravity, 2576.
Eig. 2. Has the projecting Eoman pillars, as described in
the manipulatory portion of this work, (see page 104 ;) and,
like most of the Compound Glasses, has scarcely undergone
any decomposition whatever. Specific gravity, 2483. Also
Mr. E. Smith's.
Fig. 3. Is a very rare specimen from Mr. E. Smith's collection, and displays the great perfection of ancient Glass cutting.
It formed part of an elegant drinking-cup. One peculiarity
is, its lightness; it being but little more than twice its
weight of water—viz., of a specific gravity 2049. It is quite
colourless.
The ancients bad their White Glasses both of simple and
compound character ; the latter were by far the most conservative. Specimens of the former, in the British Museum, and
in private hands, are in a state of considerable decomposition. The heat of the burning lava which overwhelmed
the devoted cities of Herculaneum and Pompeii, may have
had great effect in destroying part of the alkaline properties, (much greater than the ordinary influence of the atmospheric air,) and thus causing,in the partial decomposition, the

H.ATE

3.

ANCIENT GLASS

W ss
1 . 2 . 3 . 4 . Roman Fragmenta.
5 . 6 . 7 . 8 . 9 .10. Ancient Fragments m the British Museum,
i&Jottan*

-H-

Jobn9*u*tfyift

EXPLANATION OF THE COLOURED PLATES.

137

exterior coating to become opaque, and peel off film by film,
and layer by layer, in siliceous opalescent matter, sometimes
in iridescent tints, until the whole mass had become reduced
materially in weight; leaving part of the interior only, of a
transparent substance, comparatively porous and weakened
in structure by the loss of alkali.
Dr. Faraday, who kindly examined a piece of this fragment, proved that it softened by the blow-pipe, and took the
impression of a file. He found no trace of lead, and but little
lime; and the chief part of the alkali was considered potash. No
doubt, therefore, exists of its being ancient Glass. The large
quantity of alkali in comparison with the sand causes its peculiar
lightness; its excess together with caloric has induced exudation, roughness of surface, and the dislocation of some of its particles ; it having throughout small cracks, as if caused not by
friction but by the loss of the cementing properties of its alkali.
Another fragment of Glass, considered equally ancient (by
Mr. Koach Smith) as the former, is of a greenish tint; it has,
no doubt, iron in its constituents; and, from its compound
character, is as perfect as at the hour it was manufactured. Its
specific gravity is 2600. It has small projecting solid lumps
at regular distances from each other, intended for ornament.
A third fragment is of blown diamond pattern of heavy
Glass: it has a slight white coating or film, which yields to,
and can be removed by, the nail; is otherwise perfectly
colourless and transparent, and about the same specific gravity
as modern Flint Glass—viz., 3144. It has a polished surface,
and is in excellent preservation.
The two latter fragments being in so high a state of preservation would lead to the conclusion that their conservative
T

138

CURIOSITIES OF GLASS-MAKING.

properties are due to the presence of metallic oxide in connexion with silex, and therefore requiring a less proportion of
alkali.
Of this character of artificial crystal, the author has seen an
aneient drinking-glass, of a Medicean form, on afoot of considerable substance, and nearly entire, the property of a tourist,
who procured it from the neighbourhood of Borne. It is
remarkably heavy, and appears as if it had been shaped all
over at the cutting lathe, so as to raise rings out of the
exterior of the solid Glass, they were certainly not welded on
in the ordinary manner while hot; and the vessel has the appearance of having been blown in an open-and-shut mould, like the
modern Bohemian Glasses, and the rim afterwards cut off and
polished. Although no opportunity has been afforded of taking
its specific gravity, it a|3pears much heavier than modern Flint
Glass, and slightly yellow in tint. It is clear, therefore, that
the ancients had not only the art of colouring Glass, and of
using lead in these imitations of the precious stones, but they
had (at what precise period in history is unknown) likewise
the knowledge of the use of lead, and perhaps barytes, to give
to white Glass density and refractive beauty. In truth, the
more a manufacturer gets acquainted with ancient fragments, the more firmly he appreciates the high state of perfection to which ancient workers in Glass carried their interesting art, but of which skill we find few records in ancient
literature.
Fig. 4. Part of an ancient handle of the specific gravity, 2500.
Its green tint is indicative of the presence of iron. It is in a
high state of preservation owing to the conservative tendency
of the iron which forms one of the constituents. The workmanship is ingenious.

jar

»

k

-J
PH

#8

EXPLANATION OP THE COLOURED PLATES.

139

Figs. 5, 6, 7, 8. Are specimens in the British Museum of
the delicate and beautiful mosaic pictures worn, probably, as
rings or brooches, when mounted in gold, by the ancients.
Fig. 9. The formation of this pattern differs from the mosaic ;
and it is somewhat difficult to imagine the manipulations of
the Glass-maker in working out its peculiar design.
Fig. JO. Curious specimen of ancient cased Glass, of the
same class as the Portland vase, also from the British
Museum.

PLATE IV.
ANCIENT VENETIAN SPECIMENS.

Fig. 1. Ancient Venetian cup and cover, called Vitro di
Trino. This specimen was purchased about the year 1836, at
the sale of the collection of Lady Bagot. The position of
the entrapped air-bubbles varies, when the mass is stretched
out of its original structure, they are upon the diamond
crossings of the white enamel threads, as fig. 3 ; although,
usually, between the junction of the angles, as fig. 4. The
foot is made by a ring neatly cast upon the bottom of the
cup, within which all the white enamel lines concentrate
to the centre, with the accuracy of lathe or engine turning.
Fig. 2. Ancient Venetian frosted vase; formerly the property of Lady Bagot, subsequently of the author. The satyr
heads have been impressed by a seal or die, after the vase was
frosted, the gilding of which, as well as the border or rim, has
been fixed by burning. The frosting manipulation and the
Vitro di Trino are explained at pages 1J3 and 114.

140

CURIOSITIES OF GLASS-MAKING.

PLATE V, *
GRECIAN AND MISCELLANEOUS SPECIMENS.

Fig. 1. This fragment, in the possession of W. R. Hamilton, Esq., seems to be the ne plus ultra of the chemical and
manipulatory power of the ancient Glass-maker. It consists
of no fewer than five layers or strata of Glass, originally forming a portion of a vase. The interior layer is the usual blue,
sapphire colour; and the green and red coatings are similar
to those analysed by Klaproth. The colours of the numerous
strata (see the section) are separated from and contrasted
with each other by layers of white enamel, skilfully arranged
by some eminent artist of the school of Greece, for the embossment of his cameo subject, as well as for blending them
into each other artistically. The subject—a female reposing
upon a settee—is executed in the very highest style of art,
and is a fine specimen of gem engraving. The drawing is
the size of the fragment.
Fig. 2. A Patera of ancient Grecian or Eoman Glass, decorated with the moulded Koman pillar, of light green tint, but
slightly opalescent, and iridescent through decomposition of
surface. It is in the London Polytechnic Institution,, and
was found in a tomb, in one of the Grecian islands.
Figs. 3 and 4 are green Osorian vases in the British Museum.
The largest is about fifteen inches high, in excellent preservation; and both are beautiful specimens of the art,—especially
the handles, which show the perfection of the ancients in the
art of Glass-making. The material is common, and resembles

PLATE 5
* 4-

1 . Hiiuicnl Mosijir
2. Ar,t,ii]!it' I'i'.i;-'^ V
3 . ftotnan V;i;;o

PLATE

I . Ven ou an Hall
2. Millofiore
3 . 4 . 5 . Roman Fragments

6

6 Artificial Surdouyx.
7 . Roman Mosaic- Gum.
8 . Chinese (HiiKS

EXPLANATION OF THE COLOURED PLATES.

141

our ordinary Crown Glass. These large pieces required correspondingly large crucibles and furnaces for their formation;
but whether they are of Roman or earlier manufacture, it is
difficult to decide.
Fig. 5, the Chinese lion, is cut by the engraver's tool from
a solid pedestal of Glass, of great density; probably, made
from broken English Flint Glass, with an addition of oxide
of lead. The execution, as a work of art, is by no means
pleasing, but as a piece of ingenuity and uncommon industry
it is a curiosity: it may be seen at the Museum of Geology,
at Charing Cross, at the head of which institution is Sir H. de
la Becne, to whose kindness the author is much indebted.
Fig. 6. A small glass rosette, brought from China, in the
collection of the Propaganda at Rome.
Fig. 7. A small green glass lion, exhumed at Tivoli.
These specimens are sketched from Minutoli's work, and
serve to show the variety of countries whence fragments of
ancient glass have been discovered.

PLATE VI.
ANCIENT MOSAIC, CHINESE, AND VENETIAN SPECIMENS, ETC.

Fig. 1. A solid ancient Venetian ball, consisting of fragments
of filigree cane, placed in a hollow, transparent, white Glass
pocket, and collapsed by extracting the air as the mass fuses
together by the heat of the furnace.
Fig. 2. S23ecimen of modern French Mille-Fiore Glass,—
formerly made by the ancients and the Venetians: it consists
of slices off the ends of cones, of various colours, inclosed in

142

CURIOSITIES OF GLASS-MAKING.

white transparent glass, as described in the manipulatory
portion of the work. (See page 110.)
Figs. 3, 4, and 5. Ancient Glass, in the possession of Mr.
Eoach Smith. These varieties are produced by mixing small
Glass bugles or beads with masses of fused green, purple, or
azure-blue glass. They are curious and interesting, and in
excellent preservation.
Fig. 6. Crude artificial sardonyx—from the British Museum
—of three layers of opaque coloured Glass: this, it is supposed, was manufactured for the Grecian artists at Eome, for
the purpose of cameo-engraving, or for cutting into other
gems of high art, and no doubt afterwards suggested larger
gems and vessels, such as the Portland and other vases; also
the vase described by Minutoli (the neck and handle of which
are in the cabinet of Mr. Eichardson Aldjo, and the remainder
in the British Museum); likewise the Naples or Pompeii vase.
(See Plate 1.)
Fig. 7. Fragment of Mosaic Glass, which, as well as fig. 6
in the British Museum, is a beautiful exemplification of the
art of making pictures of Glass, with variously-coloured threads
of Glass fused together, as described by Wincklemann and
others; by means of which, elegant arabesque designs were
executed by the ancients.
Fig. 8. Specimen of Chinese Glass, in the possession of
the author. The constituent of the yellow colour is unknown.
The Glass is supposed to be chiefly composed of felspar; the
heads are impressed by metal dies. The foot is of wood.

VIGNETTE IN TITLE PAGE.

T H E Portland, Alexandrian, Naples, and Aldjo Vases.

INDEX.
ACCIDENTS in Glass-houses, 80.
Achromatic Flint-Glass, difficulty of
obtaining, 44, 45.
Aggry Beads of Ashantee, 10,11, 135
Alexandria, Glass-houses of, 5.
Aldjo Vase, 142.
Alkali, excess of in Glass, 72, 137.
American'Pressed Glass, 121.
Amethyst, or Purple, Glass, Constituents of, 34.
Annealing arches described, 64.
Annealing, curiosities of, 69.
Annealing, principle of, 62.
Azure Blue Glass, Constituents of, 34.
Barrows, Glass vessels found in, 9.
Battledore, use of the, 82.
Blowing Iron, the, 82.
Blowing and Making Glass by hand, 84.
Blown-off and Blown-over, explained,
96.
Blue Transparent Glass, Constituents
of, 34.
Bohemia, Glass-works in, 25.
Bohemian Glass-making, 22.
Bottle Moulds, various, 103, 104.
Boys' Earnings in Glass-making, 89
—129.
Breakage in Lears, 72.
Britain, Glass-making in, 8.
British (early) Glass in the Ashmolean
Museum, 14.
British Museum, ancient Glass in, 5,
7, 17, 18, 19, 111, 122, 139, 142.
Browne, Sir Thomas, on Venice Glass,
24.

Bugles made at Venice, 25.
Cameo Incrustation described, 119.
Cameos and Intaglios, Italian Glass,26.
Cane and T u b e D r a w i n g explained,
106.
Cased Glass, 114, 115.
Casing and Welding Flint Glass, 74.
Chair, Glass-maker's, 83.
" Chairs" in Glass-making, described,
88, 89.
Chatteris, curious Glass Vase found
at, 9.
Chest Knife, use of the, 101.
Chinese Glass-making, Ancient, 15.
Chinese Specimens described, 141,142.
Cinerary and Osorian Glass Urns in
the British Museum, 19, 140.
Clay, to knead, for Pot-making, 53.
Cobalt for colouring Glass, 74.
Coffins, Glass, used by the Egyptians, 3.
Coloured Glass, Ancient and Modern,
74.
Coloured Glass, varieties of, 73.
Compound Glasses, Constituents of, 33.
Constituents and Manufacture of Glass,
33, 137, 138.
Copper for colouring Glass, 74.
Crystallo-Ceramie, the Patent, 29.
Crystallo Engraving described, 118.
Cutting Glass operations, 124.
Discovery of Glass, said to have been
accidental, 1.
Devitrification, phenomena of, 69, 70;
Diamond etching on Glass, 127.
Drinking Glass, Roman, 138.

144

IND EX.

Drop Pinching, operation of, 122.
I Glass, Crown, Plate, and Bottle, Constituents of, 33.
" Druid Holy Snakes" found in Wales, 9.
Glass cutting, or grinding, operation
of, 123.
Earnings of Glass-makers, 90, 91.
Edward the Confessor's Tomb, Mosaic Glass-engraving described, 125.
Glass-house Pots, English and French,
Glass on, 6.
47,48.
Egypt, Ancient, Glass-working practised in, 2.
Glass-houses, improvement of, 128.
Egyptian Glass-making processes, 4,5. Glass Stoppering operations, 127.
Egyptian specimen, Plate 2, 133.
" Glory Hole," the, described, 65.
Goblet, or Ale-glass, in Two Pieces,
Elasticity of Flint-Glass, 38.
how made, 86.
Emerald Green Glass, Constituents
Gold for colouring Glass, 74.
of, 34.
Gold Topaz Glass, Constituents of, 34.
English Glass, superiority of, 27.
English Glass-houses, the first, 27.
Grecian Specimens described, 140.
Engraved Bohemian Alexandrian
Handled Jug, to make, 97.
Glass Vase, beautiful, 22.
Engraving on Glass, operation of, 125. Hebrews, Glass known to the, 4.
Engraving on Glass invented by the Herculaneum, Glass discovered at, 6.
Howel's " Familiar Letters," Glass
Venetians, 24.
mentioned in, 22, 23, 24.
Etching on Glass, 127.
Ethiopian Statuette, fragment of, 134.
Excise regulations and Annealing, 67. Incrustation, antiquity of, 28.
Excise regulations prej udicial to Glass- Inscription Plate, in crusted Glass, 31.
Tntaglio engraved Vase, fine, 22.
making, 52.
Iron for colouring Glass, 74.
Faraday's, Dr., Examination of Ro- Isis Idol, fragment of, 134.
man Glass, 137.
Faraday's, Dr., Optic Flint Plate Ex- Johnson, Dr., his philosophical reflections upon Glass-making, 130.
periments, 44.
Ju stone, artificial, 16.
" Flashing," importance of, 61, 87.
Flint Glass-blower, art of the, 128.
Kew Conservatory, Glass in the, 76.
Flint Glass, Constituents of, 34, 35.
Klaproth's Analyses of Coloured
Flint Glass Works described, 45, 46.
Glasses, 76.
Flues and fire-places of Furnace, 57.
French and English Glass-houses compared, 46, 47.
Labour, Division of, in Glass-making,
Fuel, consumption of by Furnaces, 60.
87.
Furnaces described, 56.
Lamp-Glass, Cylindrical, to make, 94.
Furnace, state of, on commencing Lamp-Shade, French, to make, 99.
Leakage in Pots, to stop, 55,
•work, 79.
Fusing and Blowing, in Glass-making, Lear, or tier, the, described, 64.
Lightness of Ancient Glass, cause of, 7 8,
49.
137, 138
Gathering Glass, how effected, 79.
Glass-manufacture, beauty of, 130.
| Malleable Glass, 6.

INDEX.
Management of a Furnace, 59.
Manager of a Glass-house, 92.
Manganese in Flint Glass, 70.
Manipulations of Glass-making, 80.
Manipulatory Conditions of Glassmaking, 40.
Manipulatory Processes described, 84.
Marver, the, work of, 82.
Melting P o t s , Manufacture of, 50, 5 1 ,
52, 53.
" Metal," Varieties of, 91.
Metals for tinting Glass, 76.
Millefiore Glass of Venice, 25.
, how made, 110.
Minutoli's
Analyses of Coloured
Glasses, 77.
Mosaic Glass, ancient, 17.
Mosaic Glass in the British Museum,
18.
Mosaic Glass, Roman and Venetian, 26.
Mosaic Specimens described, 143.
Mosaic W o r k , how managed, 110.
Mosaic and Millefiore Glass, 141, 142.
Moulded Bottles, to make, 102.
Moulded Roman Pillars, to make, 104.
" Moves" in Glass making, 90.
Museum of Economic Geology, curious
Glass in, 16.
New application of Glass wares, 32.
Naples Vase described, Plate 1, 131.
" O m n i b u s e s " used in Annealing, 66.
Opaque H a r d White Enamel, constituents of, 34.
Opaque Soft White Enamel, constituents of, 34.
Optical Glass, Constituents of, 37.
Experiments, by Guinand, Frauenhofer, Bontemps, & c ,
4 1 , 42, 43.
Orange Glass, Common, Constituents
of, 34.
Outline forms of Glass, new, 128.
Payment, Mode of Glass-making, 87.

145

Phoenicians stated to have discovered
Glass-making, 2.
Pictures of Mosaic Glass, 25.
Pillar-moulding improvement, 105—
106.
Pliny, his account of the discovery of
Glass-making, 2.
Pompeii, Glass discovered at, 2, 6.
Pompeii, Glass Vase found at, 18.
Ponty, or Pontil, use of, 82.
Portland Vase, the, described, 19, 20,
132.
Potash in Glass-making, 36.
Pot, to set in the furnace, 53.
Pots for various Glasses, 50—51—52
—53.
Pressed Glass invented in America,
31.
Pressing Glass, operation of, 121.
Pucellas, use of the, 8 1 .
Red Lead in Glass-making, 37.
Retort, to make, 95.
Ringed Decanter, to make, 101.
Roman and Early British Glass found
in Suffolk, 12.
Roman Fragments described, 136.
Roman Glass found in London, 10,
13.
Roman Glass in the days of Nero, 7.
Roman Glass in the British Museum,
8.
Roman Glass-cutting, 15.
Rosettes, Welded, for Windows, 117.
Ruby Red Glass, constituents of, 34.
Saltpetre in Glass-making, 37.
Sands for Glass-making, 35.
Sardonyx, Crude, Artificial, described,
142.
Saxon Glass found at Cuddesden,
Oxon, 13.
Schools desirable in Glass-houses, 129
Scolloping or Cutting, 96.
Separation by Contraction in Glass,
40.

146

IN:

Servitor, or Footmaker, the, 83.
Shapes, new in Glass-making, 128.
Shearing Glass, 81.
Sidon, Glass said to have been invented at, 2.
Simple Glasses, Constituents of, 33.
Skylights, moulded Flint Glass, 32.
Steadiness of nerve important in Glassmaking, 129.
Superstitions respecting Venice Gls • *
24.
Tact requisite for excellence in Glassmaking, 129
Test, Flint Glass, a fine one, 39.
Thebes Fragments described, 133.
Tiseur, or stoker, in Glass-making, 48
—49.
Tools used in Glass-making, few and
simple, 61.
Tools for Manipulation, 81.
Tumbler, to make by hand, 93.
Unannealed Glass, frangibility of, 63,
Uranium, use of, in colouring Glass, 73.
Venetian Ball, how made, 109.
Venetian Diamond-moulded, to make,
112.
Venetian Filigree Glass, how made,
108.
Venetian Frosted Glass, to imitate, 116.

Venetian Glass, 24.
Venetian Glass, Ancient, described,
139, 141.
Venetian Glass, Devitrification of, 71.
Venetian Vitro di Trino, to make, 113.
Venice, ancient, Glass-making in, 21,
22.
Venice Glass, properties of, 28.
Venice Glass, superstitions respecting,
24.
Violet Glass in greenhouses, 75.
Vitro di Trino of Venice, 25—26.
Waste of Glass, 92.
Wedgwood, Mr., and the Portland
Vase, 21.
Welded coloured Glass, 117.
Welding by contact, 40.
Wilkinson, Sir J. G., on Egyptian
Glass-making, 2.
Winckelmann on Egyptian Glassmaking, 3.
Window-Glass used by the Romans, 6.
Wine-glass in Three Pieces, how
made, 84.
in Two Pieces, 86.
Working Crisis, in fusing Flint Glass.
37.
Workmen, great proportion of, in
Glass-making, 130.
Yeschm, artificial and real, 16.

Savill & Edwards, Printers, 4, Chandos-street, Covent-garden.