ť:
ș.§ ° ）
į . . ſ ,
-*|+ →
{*
!
# -- - - --~~~~--~--~--~--~~~~ ~~~~ - - - ---~ ~ ~ ~ -- - - - ----- - ----- - - - ~~------ --~~~~- - ----
?ĒĻĻĽĮŁĘTIȚIIIIIIIIIIIIIIIIIIIII7IIIIIIIIIIIIŲJĮĮĶĶĹĹĻĻĽĮĮĶĶĹĹĻĻĽĽŁ
=№:：：：：：：：：:：:：：：：：：TSJºſe§@₪∞, ∞; ∞, ∞， ∞; ∞ √≠ ≤ ∞ sº se ae → ← → • • • • • • • • • • • • •=.*= *= *F ،
ĒĒŅŠ§ff-##\,
t.• · ， ！*• •！~`NNNNNNN$（~~S∞ √∞ √º 7ſº «i =
- …»| №w ·· * �· *· · · · |-： § 9 •'.º s -##*
i »• •* |-· •„Sſā
|-）Ë
#ºļķ}ē
|}jįį
& \ + …ſ'
， *||¿| };Ë
·----º|ſ:| 5
ºſſ.{
8ºſ;#
ø{ º aeſ ）,::=}
5.ſ ≡
*ae º|ſ:#
·{Mºiſ| E
ë.}Ō#
}* |#----
!. |#|
}*§ .º aeº,© : •2} }！\ \ſºſ;3 ，，。ſā
||£35，2%ſ'，ſ@%őſiſſſſſſſ|IIIIIIIIIII###
| } ,■■■■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■، ، ، ، ، ، ، ، ، ، ،%， 8，Byº：ſº |-
\，·ĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪĪİIſfiſſiſſiſſiſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſſ!!Ì
±% :{！ -
\
3
{
#**,
{
*Źri ;-aº ºº.
ų * T *. \* …-º t * * * · * *ș* ,*
º.*ş， iş， ſº v ·.*;; ， , ， ，
！ !!€.~y &
*** 4. **.«»
*ų. {w
{ *----
į|-·’ . »- - • • • •
！ *! *};- » g ſºº• ~ … ? wºš:
|--«;-… „ . . . …, s.º. ſººſ ºs º| - -*|- - ， , ，''，''）:.**






QC
%5
F73
| 3 |5
~~~ºººººº ！！！！！！！
ſz
ſaetº?！?！?zazaeº，

RESEARCHES
AIBOUT
ATMOSPHERIC PHAENOMENA.
&"
THOMAS FORSTER, F.L.S.
SECOND EDITION,
CORRECTED AND ENLARGED;
With a Series of Engravings illustrative of the Modifications
of the Clouds, &c.
EXTIN. AN&Portoix. ANEMO.N. OTE. IIAEIXTA,
XPHXIX. EXTIN. A.” O’Y PANIQ.N. Y'AATſ, N.
OMBPION. IIAIAQ.N. NRq EAAX.
LONDON :
PRINTEn rom BALDWIN, CRADoCK, Ann Joy,
47, Paternoster-row;
THOMAS UNDERwooD, 32, FLEET-STREET; AND will IAM
BLACKWOOD, EDINBURGH.
* * * * * ~ * * * *
1815, ***** * * * * * ****
C. Baldwin, Frinter,
New Bridge-street, London.
Q
& ,
fº-º-º-º-º-, -
! ~ 3 - st g
* c 1 > (
PREFACE
TO
THE SECOND EDITION.
AMONG the many erroneous views which
people take of the origin of the sciences,
no one appears more common than that of
supposing that they have all been originally
undertaken and pursued with some particular
aim to public or individual utility; as if the
investigation of nature was not valuable; nor
natural phaenomena capable of exciting us to
the pursuit of their causes, on account of the
pleasure they produced in engaging the ener-
gies of our different intellectual faculties, in-
dependently of any further purpose to which
they might be made subservient. Some ima-
gined object of utility, for the attainment of
which people consider the different sciences
as valuable, has generally been supposed to be
the cause which has impelled mankind to fol-
low them, as if from feeling certain exigen-
cies arising from time to time out of the pro-
a 2
iv PREFACE.
gressive civilization of society, men had been -
taught to love the pursuit of knowledge and
the exercise of reflection, by the imperious
calls of newly created wants. This is a very
old opinion. People too, having confounded the
causes of excitement existing around us in the
world with the various faculties of the mind
to be excited, have even supposed that our
propensities, sentiments, and our intellectual
and reflecting powers have been derived
from education; and that from the contin-
gent circumstances of different individuals
have arisen the varieties of the human cha-
racter; without reflecting on the infinite va-
riety of organization observable in individuals.
throughout the creation, and without ever,
perceiving that unless there were conditions
in ourselves of the different manifestations
of the mind, the objects around us could
never excite, nor education ever improve OUlt
several faculties. I have always believed that
there were differences in the native structure
of persons which independently of, though
perhaps modified by, early habits and associa-
tions, have inclined them naturally to the pur-
suit of different branches of science. And, I
think, the recent investigations of modern
physiologists will verify this opinion, and will
PREFACE. w
demonstrate the material conditions necessary
to the multiform manifestations of the mind.
People having the idea that every thing is
valuable for some secondary object; this ob-
ject to which an imaginary value is attached
varies in the minds of different persons, ac-
cording to their own particular conformation of
mind and to their education. In many, the ag-
grandizement of property being the prevailing
passion, scarcely any thing is considered use-
ful, except that which contributes to public
or private wealth. In others, the degree in
which any science or art can contribute to
common convenience, or abridge labour, be-
comes the measure of their estimation of it.
Judging of others by themselves, people have
supposed that the sciences have always been
cultivated for such secondary reasons, and that
in the early stages of society, they arose out
of the numerous artificial wants which advanc-
ing civilization was continually producing. But
though it has generally been the case with
the multitude who have followed up the
discoveries of the ingenious, that availing
themselves of the intellect of their superiors,
they have erected a trade on their inven-
tions, or have converted them to purposes
of social improvement; yet many of those phi-
\
1.
wi PREFACE.
losophers, to whom society has been indebted,
for the most important improvements in the
sciences, have cultivated them originally for
the sole pleasure which the pursuit itself af.
forded. There have been in all ages, persons
who have taken delight in observing and com-
paring natural facts, and for whose philosophic
minds the infinite variety exhibited by all na-
tural objects, and the investigation of the
respective causes of different phaenomena, are
of themselves sufficient to engage them in the
pursuit of science, and the knowledge obtained
thereby an adequate reward for their labours.
In the earliest ages, as far back as history ena-
bles us to trace the operation of the human intel-
lect, we find mankind interested aboutmeteorolo-
gical phaenomena. A circumstance by no means
astonishing, when we consider the vast impor-
tance of this science to the shepherd and agri-
culturist, and the interest the study of it
engaged, as a means of enabling men by anti-
cipating the event of terrible atmospheric com-
motions, to provide in some measure against
their effects. The beauty, also, of many atmo-
speric phaenomena, and the interesting variety
of scenery which they produce for the specta-
tor; together with the natural curiosity excited
about their causes, which man is organized to
PREFACE. wii
feel, have contributed probably in a great mea-
sure to interest people in this science.
Meteorology considered as a subject of
amusement seems to have some advantages
over many other pursuits; inasmuch as it may
be studied and will afford interest in places un-
favourable to the cultivation of other sciences.
The botanist, who delights in the diversifica-
tion of nature exhibited in the endless variety
of the forms and colour of flowers; or the na-
turalist, who finds amusement in contemplating
the habits of animals, and the adaptation of the
structure of each to its mode of life, cannot in-
dulge their inclination except in habitable coun-
tries, or where vegetation and life abound.
But on the barren mountain’s rugged vertex,
in the uniform gloom of the desert, or on the
trackless surface of the ocean, we may view
the interesting electrical operations which are
going on above, manifested in the formation
and changes of the clouds, which bear water
in huge masses from place to place, or throw
it down in torrents on the earth and waters;
occasionally creating whirlwinds and water-
spouts; or producing the brilliant phaenomena
of meteors and of lightning; and constantly
ornamenting the sky with the picturesque
imagery of coloured clouds and golden haze.
viii PRERACE.
The atmosphere and its phagnomena are every
where, and thunder Rolls, and rainbows glitter
in all conceivable situations, and we may view
them whether it may be our lot to dwell in
the frozen countries of polar ice, in the mild
climates of the temperate zone, or in the
parched regions which lay more immediately
under the path of the Sun,
Among the ancient nations of oriental shep-
herds, the cultivation of this science must
have been particularly useful; chemistry and
promotion of a more cultivated condition of
society, for the improvement of the arts, and
manufactures of civil life, were of less utility
among tribes, whose chief employment consisted
in watching their flocks, and procuring the
fruit and other vegetable productions on which
they subsisted.
Constantly abroad in a serene atmosphere,
and endowed with strong faculties for ob-
servation and analogy, the eastern tribes of
old, in Aegypt and Syria, observed accurately
the phaenomena of the heavens, and collect-
ed, compared, and recorded, facts that laid
the foundation of astronomy, and meteoro-
logy, which the Grecian and Roman philoso-
phers continued to cultivate, and which have
PREFAÉE. ix
bega, brought nearer to perfection in later
timeå, * * . . . . r g
Meteorology, regarded as a science distinct
flora astronomy and astrology, appears to have
been first systematically treated of by Aristotle,
who seems by his works to have been con-
stantly employed in observing and comparing
natural objects. He described with accuracy
many atmospheric phaenomena, and employed
himself in investigating their causes. He as-
signed the cause of the rainbow, and of the
halo, and appears to have given a more minute
detail of the various appearances of clouds, rain,
hail, snow, dew, meteors, and other phaenomena
which occur in our air than any preceding
or cotemporary writer. Shortly after him
Theophrastus, who had been his pupil, collected
all the popular prognosticks of the weather,
under four heads; 1, IIsp, a nuovov vstau; 2, IIsaº
a nº.2 raw &v=pov; 3, II; anº.2 row x+...ovov, and 4,
IIept ºnwarov ivºſov : these prognosticks Aratus
soon embodied in his Diosemea, which was a
sort of appendix to his astronomical poem the
Phaenomena, translated into Latin verse by Ci-
cero, by Germanicus, and by Festus Avienus.
We find meteorological observations inter-
spersed in the writings of the Greek historians;
and the frequent allusion to atmospheric phae-
X. PREFACE.
momena by their poets shows the attention
which was generally paid to such subjects.
The simplicity and correctness of narration
adopted by the Greeks was probably the result
of the prevailing perfection of their physical
organization which is one of the principal
conditions of intellectual excellence, and in
which their philosophers excelled most of
those of more modern times. The heads of the
ancient Greek philosophers are of a remark-
ably fine form for intelligence.*, The Romans
who wrote on meteorology of any note were
Pliny, who in his Natural History, lib. xviii.
* The heads of many of the Roman philosophers, and in-
deed of those of all countries, ancient and modern, did certain-
ly, as well as those of the Greeks, refute Juvenal’s saty-
rical assertion fronti nulla fides, if he ever really in-
tended such as a serious observation; but the configuration
of the heads of those celebrated ancient nations, who gave
birth to the sciences from the native energies of their intel-
lectual faculties, is more particularly calculated to illustrate
and confirm the motions of modern physiologists respecting
the intimate connection between the physical strength of the
organs of the brain and the intellectual and moral character
of the individual. A subject which has been ably treated
of by the celebrated anatomists, Gall and Spurzheim, who
by their elegant dissections of the brain, and their compa-
rison of the brains of different animals with the proper habits
of each, seem to have roused comparative anatomy into some-
thing like a systematick science. Dr. Spurzheim has just
published a large work on this important science, The
Anatomy and Physiology of the Brain.
6
PREFACE. xi
cap. 35, wherein he treats of the prognosticks
of the weather, confounded his observations
with abundance of fabulous and absurd narra-
tions; Virgil, who in his Georgics imitated
the prognosticks of Aratus; Lucretius, who
endeavoured to assign physical causes for most
of the popular phaenomena of the heavens; and,
lastly, Seneca, with whose superfluous tautology
in his Natural Questions, every one who has read
them must have been heartily tired. In the
works too of many of their other-writers we
find traces of their meteorological knowledge.
It is a pity we know so little of the collateral
history of this as well as of the sciences among
the Chinese and Arabians; and among other
eastern tribes of the present day.
Little account of the state of our science can
be traced from the time of the ancient Romans
to the revival of letters in Europe; and it was
not till the middle of the last century that any
advancement was made in meteorology. Dur-
ing the dark ages which elapsed between the
decay of the Roman Empire and the revival
of literature; when the works of art and
science again fell a prey to superstition and bar-
barity, and when the enlightened philosophers
of Greece and of Rome resigned their pre-
eminence in the republick of letters, and gave
#if PREFACE.-
way to a loathsome band of crafty and over.
ruling zealots, who being themselves the sport
at onee of pride, of craft, and of superstition,
exerted the full force of their assumed power
to enslave the minds of the already degenerate
race of the people, and to banish from them all
vestiges of literature and of philosophy; at this
disgraceful period which is a blot in the natu-
ral history of the human species, meteorology
like every other science perished, and all the
observations and records of former observers
were forgotten. But the stream of time is a
fluctuating torrent, and intellectual excel-
lence seems to flourish at alternate periods.
Shortly after learning again began to flourish,
and the energies of the human mind again
exerted themselves according to the particu-
lar genius of individuals, there appeared
persons who delighted in aérial phaenomena,
and Saussure De Luc, Bertholon, and others at
length roused the attention of mankind to the
production of our atmosphere. The attention
of philosophers since their writings seems more
particularly to have been directed to these sub-
jects, which can only be brought towards per-
fection by the repeated observations of people
in different places. To add what few I have
made myself, and to engage the attention of
PREFACE. xià
more; able; and industrious meteorologists, to
some facts in the ‘science at , present little
known, is, the reason of the present publication,
ºr. In conclusion of this rude sketch of the
science from its earliest records to the present
day, we' are naturally, led to reflect on the
melancholy, picture of the revolution of human
society; which the history of almost any science
or 'art, will always. excite. Science seems to
have illumined, first the banks of the Nile,
and to have dawned on the early tribes of
Aegypt; travelling down from Thebes to
Memphis and Cairo, it took a westerly
course to Athens, to Rome, and to the
many illustrious states which afterwards distin-
guished modern Europe. But in tracing her
progress we find nothing left in her course, but
the skeleton of former greatness. The ruins
of stupendous cities once the ornament of
the east ; the numerous fortifications, walls,
temples, aqueducts, and other works of art, now
nothing but the desolated habitations of wild
animals, and the traces left of sciences which,
like fruitless flowers, bloomed in the spring of
time only to decay, are monuments of human
fatality which must impress reflecting persons
with gloomy notions of the instability of society,
and incline us to fear that, in spite of all the
xiv a PREFACE.
efforts of genius and of art of modern times,
the lightofknowledge which rose in the east, and
civilized the oriental nations, will set on the
western parts of the world, and leave us ere
long a monument to future ages of the fluctuat-
ing nature of human perfection, unless by a
strict attention to the improvement of the
physical organization of our species, conjoined
with the adoption of some general plan of edu-
cation superior to any hitherto enforced, we
should permanently improve the moral and
intellectual character of future generations;
without which all the scientific records imagi-
nable would be to them only as cyphers
scrawled on the barrenness of intellect.
$
3.
º
CONTENTS.
CHAPTER I.
Pag
Of Mr. Howard's Theory of the Origin and Mo- €
difications of Clouds. . . . . . . . . . . . . . . . . . . . . . . . 1
CHAPTER II.
Further Observations about the Peculiarities of the
Clouds e e º e e e e o e º e s e e e o e e • e o e º C C C C C C C C C & C 42
CHAPTER III.
Of certain Accensions which appear to take place
spontaneously in the Atmosphere, called Falling
Stars, Meteors, etc. . . . . . . . . . . . . . . . . . . . . . . . . 114
CHAPTER IV,
Of Indications of future Changes of Weather. .... 129
CHAPTER V.
of the Influence of Peculiarities of Weather on the
Functions of organized Bodies . . . . . . . . . . . . . . . 165
CHAPTER VI.
Some Particulars concerning Winds ............ 188
CHAPTER VII.
Of Electricity. . . . . . . . .
e e o 'º e tº e º O C C tº e º O O C C C C C e 186
xvi CONTENTS.
CHAPTER VIII.
. Page
Further Investigation of the Pºuliſiº of Weather, 212
. . . . . .” - º 3r
. . . . . . . . .3
CHAPTER IX.
Some miscellaneous Observations on Atmospheric
Temperature and Pressure . . . . . . . . . . . . . . . . . . 224
. . CHAPTER X.
Of several superstitious Notions which appear to
have had their Origin in an Observance of certain
Meteorological Phagnomema. . . . . . . . . . . . . . . . . 231
t
* , •
Appendix, containing Observations on Diet as con-
* f
nected with the Influence of Atmospheric Diseases
—Quotations from Authors on Meteorology, &c. 251
I
t
' ' ', * * , , , ; # - . 3
Explanation of Plates ... . . . . . . . . . . . . . . . . . . . . . 2
; * , {
7
&
$ 2
*
t t Jº * & --
t * .# º * * # * g t $. w
Qf the Publishers of this Work may behad, by the same Author,
1. APATor AIozHMEIA, Arati Diosemea, Notis ex Collatione
Scriptorum illustravit Thomas Forster, &c.
2. Observatrons on the BRUMAL RETREAir or THE Swaſhow, &c."
3d edition, enlarged.
3. PHYSIOLogical REFLECTIONS, &c.
§
y # sº
* * * **, “A * c - ºr ^3 * -
$* ty # * g
* *** g
^. * *-
* ł 2 {} + +f *
f
Jº 3 *
4 & *
Q Aº
#
*s 2 * *
CHAPTER I.
OF MR. HOWARD’S THEORY OF THE ORIGIN AND
MODIFICATIONS OF CLOUDS.
gr **.
A cloud is a visible aggregate of minute
particles of water suspended in the atmo-
sphere. In the more extensive signification
of the word, smoke, and all the visible
effluvia of volatile substances, may be con-
sidered as clouds: meteorologists have, how-
ever, confined this term to aqueous par-
ticles.* -* -*.
* Our English word cloud is derived of the Anglo-
Saxon verb hliban or Lehliban, tegere, to cover; from
the same verb came glade, blot, lot, and lid. In like
manner, the Latin nules, and its diminutive nebula,
came from the Latin verb nullere; and from the same
verb is derived nupta. So the Greek vspo; and vstºn
from vspecy. It need hardly be observed here, that all
# B *.
2
OF CLOUDS. CHAP. 1.
Before I speak of the origin, suspension,
and varieties of clouds, and of their destruc-
tion by rain, some preliminary observations
will be necessary. Aqueous particles, and
other volatile substances, may be either dif-
fused in the air, or may be dissolved in it.
But diffusion and solution are things quite
different from chemical combination.
A cloud may either be so diffused as to
cease to be visible as an aggregate, or it may
be taken into solution by the air: in the
former case, a hazy turbidness; in the latter,
an additional clearness of the sky; would
probably be the consequence.*
that words can do, is to express some of the qualities of
the thing they represent; they serve merely as hints for
the production of ideas.—See TookE’s Ewicz II’regosºro,
4to. vol. ii. 196.
* A cloud may be the consequence of vapour, upraised
into the air, and afterward more condensed into visible
particles, by an alteration either in the temperature or
pressure, whereby the air cannot hold so much vapor
in solution as before. Some recent discoveries have,
however, led to a supposition that, under particular cir-
cumstances, the air itself may be decomposed so as to
deposit water, which may again be taken up by the air.
Thus we come back again to the old opinion of Aristotle:
E! ºn Yiveral vºwſ & aspo; hai &ng så Öaro; a two wor' attláyou
ruyiratz vºn wara toy & Torov, &c.—Meteor. lib. i. cap.3.
CHAP.1. OF CLOUDS. $
I speak first of clouds, because in the
observance of the yarying countenance of
the sky, as Mr. Howard terms it, and of its
connexion with atmospheric changes, con-
sisted the popular meteorology of the ancient
agriculturists, who were chiefly concerned to
inquire
Quo signo caderent austri, quid saepe videntes
Agricolae proprius stabulis armenta tenerent.
And the accuracy of their observations,
with respect to prognostics of the change of
weather, have been verified by those of more
modern meteorologists. It is obvious, how-
ever, that the ancients wanted definite terms
whereby to express the peculiarities observ-
able in clouds and other atmospheric phae-
nomena; a deficiency which has been in
some degree supplied by the moderns, and
particularly by Mr. Howard, whose theory
of the formation and destruction of clouds
appears, as far as I am capable of judging,
to be extremely accurate in most particulars.
As it will be necessary for me to have perpe-
tual reference to this theory, and as I shall
always use the terms which he has adopted,
it will be proper to present the reader with
R 2
4. of CLOUDS. Chap. 1. $1.
the substance of it, as nearly as I can recol-
lect it, with such additional observations as
I have been enabled to make since, together
with references to those passages in the
writings of the ancients which appear to
bear upon the subject. *
I shall not pretend, however, to give ex-
actly Mr. Howard's observations, but only
an abstract of the principal facts, as far as
they immediately relate to the origin and
appearances of the clouds; for further par-
ticulars, I refer the reader to the original
paper printed in the Philosophical Maga-
zine. $.
SECTION I.
Of the artificial Distinction of Clouds.
CLouds are distinguished by seven mo-
difications, the peculiarities of which seem to
be caused by the agency of electricity: for
example, three primary modifications, the
CIRRUs, the CUMULUS, and the STRATUS:
two, which may be considered as inter-
mediate in their nature, the CIRRocu-
MULUs, and CIRRoSTRATUS; one, which
CHAP. 1. $2. OF CLOUDS. 5
appears to be a compound, the CUMULo-
STRATUs; and, lastly, the CUMULOCIRRo-
STRATUS, or NIMBUs, a state which imme-
diately precedes the resolution of clouds
into rain. y
SECTION II.
Of the Cirrus. Pl. I. Fig. 1.
CIRRVS. Def. NVBEs crºRATA TENVISSIMA QVAE
WNDIQVE CRESCAT.
THE cirrus is a cloud which appears to
have the least density, and generally the
most elevation, and which has the greatest
variety of extent and direction. It may truly
be called the Proteus of the skies; for, in
some kinds of weather, its figure is so rapidly
and so continually changed, that after turn-
ing the eye away from it for a few minutes,
it will frequently be found so completely al-
tered as scarcely to be identified as the same
cloud. This, however, is not always the case;
it is sometimes visible for many hours and
even days together, without much changing
its appearance. I shall briefly mention some
of its most common varieties, together with
,6 § OF CLOUDS. CHAP. 1. § 2,
the circumstances under which they generally
appear.
After a continuance of clear weather, the
cirrus is frequently the first cloud which is
seen. In this case it often looks like a fine
whitish thread pencilled, as Mr. Howard
expresses it, on the clear blue sky: to this
other faint lines of the same kind are added
laterally; they increase in size and length,
and often serve as stems from which nume-
rous branches proceed, and become other
cirri of the same kind. These linear cirri
will generally be found to be very high
in the air, the lines frequently extend
quite across the welkin, while their ends,
being lost in either horizon, appear, from a
well known optical deception, to converge
into one point. They do not always extend
in parallel lines; they frequently diverge, or
increase obliquely downwards. Sometimes
transverse lines are formed, which intersect-
ing the others at right angles, give to the sky
the appearance of being covered with a
beautiful network. Of late, by way of dis-
tinction, I have used certain specific names
for the various forms of each modification,
I have called this netlike feature the reticu-
Chap. 1. $2. OF CLOUDS. 7
lar cirrus. Those which are local and de-
tached, and which ramify in many direc-
tions, giving the idea of a distended lock of -
hair, may be denominated comoid cirri.
Sometimes numerous little filaments appear
like bundles of thread, which I have
called filiform cirri. In fair, dry weather,
with light gales, obliquely descending bands
of fibrous texture are often seen, and fre-
quently move slowly along from the leeward
in a supervening current. I by no means in-
tend, by the above account, to infer that the
appearances of the different kinds of cirri, or
indeed of any cloud, are ever quite uniform;
on the contrary, scarcely two occur exactly
alike; and there are many features so vari-
Öus and so mixed, that a particular descrip-
tion of each can scarcely be attempted. In
some kinds of weather, the numberless and
ever changing figures which this cloud is
continually presenting to the eye, baffle all
attempt at description. Practical observa-
tion affords the only means of 'becoming
acquainted with them.
The observations of Mr. Howard, as well
as those which I have made since the pe-
rusal of his meteorological papers, have in-
duced me to believe, that, under whatever
8 of CLOUDS. CHAP. 1. § 2.
form the cirrus may appear, it must always
be regarded as a conductor of the electric
fluid. Its very texture seems indicative of its
particular office. The long parallel and
elevated lines are probably equalizing the
electricity of masses of air very remote from
each other. The detached comoid cirri
equalizing their own electricity with that of
the surrounding air, while oblique or de-
pending tufts appear to be conducting from
an upper to a lower stratum. The cirrus too
is sometimes interposed and conducting
between two other clouds at some distance
from each other. All the phenomena which
I have witnessed, since my attention was
directed to nepheology, are reconcileable
with this supposition; and it is probable that
a cirrus ceasing to conduct, ceases to be a
cirrus, and that it éither evaporates or passes
to some of the other modifications: in doing
which, it may often be seen in an intermediate
state, partaking more or less of the modifica-
tion into which it may be changing, and ex-
hibiting, in the progress of its metamorphosis,
very various and very beautiful appearances.
I have elsewhere had occasion to notice
the long continued appearance, and the mul-
tiform and everchanging configurations of
CHAP. 1. $3. OF CLOUDS. 9
this and the other modifications, unat-
tended by rain, and accompanied by dry,
variable, and generally easterly winds; the
abundance of nocturnal meteors, and the
intermitted actions of De Luc's aérial elec-
troscope, as indicative of a very peculiar
state of the electric atmosphere; and, I
believe, not a very healthy one.
\
SECTION III.
Of the Cumulus. Pl. I. Fig. 3.
CVMVLVS. , Def. NVBEs CVMVLATA DEN'sA svksyM
* * CRESCENS,
THE cumulus is a convex aggregate of
watery particles increasing upwards from a
horizontal base. It is commonly of a dense
structure, formed in the lower atmosphere,
and moving along in the current of wind
which is next to the earth. Its first appear-
ance is generally a small irregular spot, which
becomes the nucleus on, which it forms,
This increases in size, preserves a flat hori-
zontal base, and assumes more or less of a
conical figure. Cumuli vary in shape and
10 OF CILOUDS. CHAP.1.58.
dimensions, according to peculiarities in the
operation of the causes which produce them.
Sometimes they are pretty well defined
hemispherical masses; at others, they rise
into mountains, ranged in one plane, their
silvery summits presenting a beautiful ap-
pearance. In particular kinds of weather
I have seen cumuli of a sort of tuberculated
structure. Before rain, they increase very
rapidly, descend lower in the atmosphere,
and become fleecy and irregular in their
appearance, with their surfaces full of pro-
tuberances. In changeable weather, they
partake of the vicissitudes of the atmosphere,
and evaporate almost as soon as formed,
or quickly change into other modifications:
but, in fair and settled weather, they keep
paee in some measure with the diurnal tem-
perature, they form soon after Sunrise, arrive
at their maximum in the middle of the day,
and become very convenient skreens to inter-
cept the rays of the sun; and they subside in
the evening. It was this circumstance which
probably led to a conjecture of the parti-
cular cause of their production, which ap-
pears as follows:—The sun's rays warming
first the surface of the earth, and their
CHAP. l. § 3. OF CIOUDS. II
radiation causing warmth to be propa-
gated upward, this warmth converts water
on the earth's surface into vapour, which
rises and exerts its elastic force on that which
the nocturnal decrease of temperature had
not decomposed, and which therefore re-
mained diffused. The latter, in passing
through the atmosphere to give place to that
from below, changes its climate, arrives in a
colder air, and is thereby decomposed and
thrown into a state of visible cloud. The
simple attraction of aggeration may perhaps
cause the watery particles to collect in a
mass,” while their being similiarly electrified
may render them mutually repulsive, and
prevent their uniting to become rain. The
cumulus preserves its plane base, because it
floats on the vapour plane, or at that precise
elevation at which the air has as much water
in solution as from its quantum of heat and
pressure from above it is able to contain.
Whether the conical form of this cloud is to
be attributed to the attraction of aggregation
alone, or whether something particular in its
* This, however, is doubtful, as I mention in the aca
count of the stratus.
12 OF CLOUDS, CHAP. . $4.
electric state may also be concerned, has
never, I think, been determined. The varia-
tion of its figure, according to different states
of weather, seem to favour the latter suppo-
sition.
The cumulus, then, may either evaporate,
change into the other modifications, or, by
inosculating with any of them differently
electrified, may form the cumulostratus, and
ultimately the nimbus, hereafter to be de-
scribed.
SECTION IV.
Of the Stratus. Pl. II. Fig. 4.
STRATVS. NVREs STRATA Agvae MoDo ExPANSA,
DEORSWM CRESCENS,
THE stratus is the lowest of clouds; its
under surface usually rests on the earth or
on the water. It may properly be called
the cloud of night, as it frequently makes
its appearance about sunset, and disappears
soon after sunrise. When ascending in the
atmosphere, it often seems at a certain ele-
vation to take the irregular hemispherical
form and become a cumulus. It compre-
1
CHAP. 1. §4. . OF. CLOUDS. 13
hends what we usually call fogs and mists,
which in fine summer evenings are seen to
ascend in spreading sheets from vallies, lakes,
and fields. And which in autumn and
winter sometimes continue throughout the
day as dense fogs. It must be remembered,
however, that all fogs are not strati; some
appear to be of the modification of cirro-
stratus. . Of the latter kind are generally the
wet mists which moisten every thing on
which they come into contact.
In speaking of the cumulus, I have repre-
sented the manner in which elastic vapour
may rise into the air, on the accession of diur-
nal temperature. As the Sun sinks the heat
also is diminished, and the lower atmosphere
becomes cooler than that above. The air,
no longer capable of containing so much
vapour in solution as when it was warmer in
the day, may depositit in minute particles of
water, which may fall in the form of mist or
stratus. In the evening, too, the under at-
mosphere being as cold, or perhaps colder,
than the upper, the vapour plane is not
preserved, and cumuli by degrees may sink
down in dew. Under these circumstances,
14 OF CLOUDS. CHAP. i. §4.
they appear often to evaporate.* This
vespertine subsidence of the cumulus is
a circumstance which induces me to
believe that its diurnal existence, as an
aggregate, is not merely the result of the
attraction of aggeration. Its subsidence at
a time when the general dampness of the
air would afford a passage for its electricity
to the earth, seems to indicate the agency
of that fluid in keeping its particles collected
into the hemispherical mass in which it
usually appears during the day. f
There are peculiarities in the appearance
of the stratus, of the causes of which we are
utterly ignorant. The fine mists which creep,
as it were, along the vallies of a summer's
evening, are generally white, and, when seen
at a distance by moonlight, have a very
fanciful appearance. They are strikingly
contrasted to the yellow fogs of November. |
The stratus is found to be electrified posi-
* For further observations respecting the nocturnal
evaporation of clouds, the decomposition and recom-
position of the air, etc. I refer the reader to the next
Chapter.
Caar, 1.3% of CLOUDs. - 15
tively, and in general to be highly charged.
It is proposed to examine the air above, to
see whether there be found a negative coun-
ter charge.” -
SECTION V.
of the Cirrocumulus. Pl. III. Fig. 1.
CIRROCVMVLVS. Def. NvDEcVIAE DENSIOREs
swbRotvNDAE Ef QVASI IV AGMINE ADPoSITAE.
AFTER the cirrus has ceased to con-
duct the electric fluid, it probably either
disappears by dispersion or evaporation,
or it changes into the cirrocumulus or
cirrostratus. Its change to the cirrocumu-
lus is frequently marked by the following
circumstances: it looses its cirriform and
fibrous structure, descends lower in the
atmosphere, and assumes the form of a
number of well defined and roundish little
clouds, laying in close horizontal arrange-
ment: the change is more or less rapid on
different occasions, and sometimes takes
place in part of the cloud, while the other
part remains cirriform, or approaches to the
nature of cirrostratus. -
- * See Cyclopaedia, article Cloud.
, ºf
#6 ÖF CLOUDS. CHAP. 1. §5.
- When the cirrus ceases to conduct, it
probably becomes electrified either plus or
minus, and its conversion to cirrocumulus
seems to indicate that it has acquired a
strong positive charge. It is difficult, how-
ever, to imagine the reason why, under these
circumstances, the electrified particles should
not collect into a large body like the cumu- .
lus, instead of assuming the orbicular ar-
rangement, from which state the cirrocumu-
lus sometimes changes again to cirrus, but
more often evaporates by degrees, or passes
into the compound modifications. The cir-
rocumulus is not always uniform in its ap-
pearance, it varies in the size and rotundity
of its constituent nubeculae, and in their
closer or more distant arrangement. It is fre-
quent in summer, and often forms very beau-
tiful skies: at all times of the year it may
be seen, in the intervals of showers, and be-
fore an increase of temperature, of which
its prevalence is a pretty certain prognostic:*
* Extensive beds of cirrocumuli floating gently
along in different altitudes must have attracted almost
every body's notice; the beautiful appearance of these
clouds, with a moonlight evening, has been aptly de-
scribed by Bloomfield:
CHAP. l. § 5. OF CLOUDS. 17
#
The distinct formation of the cirrus is not
always a necessary precursor of the cirrocu-
mulus; the latter frequently forms primarily.
This may happen, perhaps, in consequence
of a supervening current of air, warmer than
the lower, and supersaturated with vapour,
which coming in contact with the colder
one below, is thrown into a state of aqueous
gas, which, from peculiarities in the electric
state of the air, may assume the cirrocumu-
lative form. The supposition that cirrocu-
mulus may be caused by an upper current,
warmer than that below, assists us to ac-
count for its being usually followed by in-
creased warmth. For many atmospheric
changes take place first aloft and proceed
downwards to the surface of our earth.
“Far yet above these wafted clouds are seen,
In a remoter sky, still more serene,
Others detached in ranges through the air,
-Spotless as snow, and countless as they’re fair;
Scattered immensely wide, from east to west,
The beauteous semblance of a flock at rest.”
The Farmer's Boy–Winter.
1s
SECTION VI.
Of the Cirrostratus. Pl. II. Fig. 2.
CIRROSTRATVS. NvDEs ExTENVATA svecocAvA ver,
vNDVLATA. NVBECVLAE HVIvs MoD1 ADPositAE.
I observed, when treating of the cirrus,
that that cloud frequently changed into some
other. Its change is generally into either
the cirrocumulus or cirrostratus: when it
passes to the latter, it descends lower in the
atmosphere, its fibres become denser and
in general more regularly horizontal, and it
usually appears subsiding, or altering its
form. The figure of the cirrostratus, like
that of the cirrus, is very various: sometimes
it consists in dense longitudinal streaks; at
others it looks like shoals of fish; sometimes
the whole sky is so mottled with it as to
give the idea of the back of the mackerel ;
this has been called the mackerelback sky;
frequently it appears like the grains of
polished wood, or is composed of fine fibres,
disposed after the manner of the fibres of
muscles, which often intersect each other.
2

CHAP. 1. $6. OF CLOUDS. 19
I have seen the cirrostratus assume the reti-
cular form, like the cirrus, from which it
can then only be distinguished by its greater
degree of density. This cloud is sometimes
spread out into a plane horizontal sheet,
more or less dense; this is the form in which
the halo generally appears. All clouds are
capable of becoming lighter or darker, ac-
cording to their relative position with respect
to the sun : the cirrostratus, however, is
remarkable for exhibiting a great variety of
beautiful colours, according to its variation
in density, to other peculiarities in its struc-
ture, or to its relative position. These ap-
pearances are best seen in the morning and
evening, when the sun is near to the hori-
zon. They have been well described by the
ancient poets,” who have likewise spoken
* VIRGIL, speaking of the prognostics of rain, alludes
to several appearances which must be ascribed to the
intervention of this cloud.
Sol quoque et exoriens et quum secondit in undas
Signa dabit, solem certissima signa sequuntur
Et quae mane refert et quae surgentibus astris,
Ille ubi nascentem maculis variaverit ortum
Conditus in nubem medioque refugerit orbe
Suspecti tibi sint imbres, namque urguet ab alto
C 2
20 * OF CLOUDS. CHAP, 1. §6.
of them as precursors of rain and tempestu-
ous weather: and modern meteorologists
have corroborated the speculative notions of
the ancients, and have observed the preva-
lence of the cirrostratus to be usually fol-
lowed by bad weather, as will be further
discussed when I come to speak of prognos-
tics of atmospheric changes.
Arboribusque satisque notus pecorique sinister,
Aut ubi sub lucem densa inter nubila sese
Diversi rumpent radii, aut ubi pallida surget
Tithoni croceum linquens Aurora cubile
Heu male tum mitis defendent pampinus uvas
Tam multa in tectis crepitans salit horrida grando.
Hoc etiam emenso quum jam decedat Olympo -
Profuerit meminisse magis, nam saepe videmus
Ipsius in voltu varios errare colores
Caeruleus pluviàm denunciat, igneus Euros
Sin maculae incipient rutilo inmiscerier igni
Omnia tum pariter vento nimbisque videbis
Fervere: non illa quisquam me nocte per altum
Ireneque a terra moneat convellere funem,
At si quum referetgue diem conditGue relatum.
Lucidus orbis erit, frustra terrebere nimbis
Et claro sylvas cernes aquilone moveri.
Wirg. Geor. lil. i. 460.
f
i
The radii diversi se erumpentes are probably the same
as the pºol, described by Aristotle, in his Meteorologica.
CHAP. 1. $7. OF CLOUDS. *1
SECTION VII.
Of the Cumaiostratus. Pl. III. Fig. 1.
CVMVLOSTRATVS. Def. NvDEs DENsA IRREgv- '
LAR is BASIN PLANAM VND190E SVPERCRESCENs.
THE change of the cumulus into the cu-
mułostratus is effected in the following man-
her: The cumulus, losing its hemispherical
figure, increases irregularly upward, grows
more dense, and overhangs its base in
uneven or rugged folds; a preexisting eirrus,
cirrocumulus, or cirrostratus, or one perhaps
immediately formed for the occasion, alights
on its summit, and inosculates. Many of
these cirrostrati are sometimes seen attached
to the cumulostratus, and sometimes to in-
tersect it. Cumulostrati frequently remain
in this state for a long time, and constitute
very picturesque skies. At other times the
processes are more rapid. The cirri or cirro-
strati are soon lost in the cumulostratus,
which increases in density, and soon be-
comes the nimbus described in the next
section. The distinct appearance of the
supersident cirri, or cirrostrati, is not neces-
3
22 OF CLOUDS. CHAP. 1. $ 7.
sary to the production of the cumulostratus;
on the contrary, the cumulus as often passes
to this cloud, and eventually to the nimbus,
without the visible precedence of any such
conjuncture and inosculation of different
modifications. But it is probable that the .
same kind of processes are going on unseen,
and that a similar change always takes place
in the electricity of the cumulus, previous
to its becoming the cumulostratus. The
change being often visibly effected by the
anastamosis of two strata of cloud, as above
described, and the two strata having been
found by experiment to be differently elec-
trified, we are led to conclude that the pro
cess of nimbification, of which cumulostra-
tus is one stage, consists in a neutralization
of the electricities of two or more clouds;
and that where cumulostratus or nimbus
appears, unpreceded by the aforedescribed
phenomena, the same kind of change has
taken place in the aqueous aggregates, from
causes which are invisible.*
The cumulostratus varies in appearance;
* See the experiments of Cavallo with the electrical
kite, &c.—Comp, Treat. Elect. 2d Ed. p. 370,
f
CHAP. i. 58. OF CLOUDS, 23
sometimes it overhangs a perpendicular
stem, and looks like a great mushroom;
frequently a long range of cumulostrati ap-
pear together, which have the appearance
of a chain of mountains with silvery tops.”
Before thunderstorms it seems frequently
reddish, which some people have imagined
to arise from its being highly charged with
the electric fluid. Of this, however, more in
another place.
SECTION VIII.
Of the Nimbus. Pl. V. Fig. 1.
NIMBWS. Def. NVBEs vBL NVBIVM congeBIEs
PLWWIAM EFFVN DENS,
CLouds of any one of the aforementioned
modifications, at the same degree of eleva-
* The simple cumulus sometimes has this appearance;
and as the change to cumulostratus is gradual, it is often
difficult to determine to which modification to ascribe it.
A continuity of base to several mountainous superstruc-
tures, and an increasing density of colour which by
degrees approximates to black, mark the progress of the
change to cumulostratus.
24 OF CLOUDS. Citat. 1.5 s.
tion, may increase so much as completely
to obscure the sky: two or more different
modifications may also do the same thing in
different elevations, and the effect of this
obscuration may be such as would induce
an inattentive observer to expect the speedy
fall of rain. It appears, however, from at-
tentive observation, that no cloud effuses
rain until it has previously undergone a
change sufficiently remarkable to constitute
it a distinct modification, to which the term
nimbus has properly been applied.* This
change seems to consist in the uniting of
particles of water differently electrified,
which, having a mutual attraction for each
other, closely unite, forming visible drops of
water, which therefore gravitate and descend
in rain. The nature of this process will,
perhaps, be better understood, if I advert to
* This application of the word nimbus corresponds
very well with the sense in which it was taken by some
of the old Roman writers, who considered it as a storm
cloud, and distinguished from imber or a shower of rain
actually falling. Thus Lucretius–
Copia nimborum, turba majore coacta,
Vrguens ex supero premit ac facit effluere imbris.
Lucr. de Rer. Nat. vi. 512.
CHAP. 1. § 8. Of CLOUDS. 25
what frequently happens in the rapid pro-
duction of showers. The cumulus, sailing
along in a lower region, appears retarded
in its progress, increases upwards, and inos-
culates with a cirrus or cirrostratus above;
then the whole changes into cumulostratus,
and spreads horizontally, forming a dense
sheet; a sort of crown of cirrose fibres
extends upward from the superior part,
while loose flocky cumuli, entering from
below, seem to nourish the growing nimbus,
which, increasing in density, at length des-
cends in rain, the drops or streams of which
appear, by inosculation in falling, to acquire
magnitude in their progress to the earth.
After the storm has spent itself, the mass is
again disunited, and formed into the different
modifications: the cirrus, cirrocumulus, and
cirrostratus, may again be seen in the higher
air, while the remaining part of the broken
nimbus flies along in a lower station, in the
form of that loose, flocky, and dark coloured
cumulus, which the sailors call scud. In
cases of more settled and continued rain,
these processes go on slower, and therefore
are less likely to be taken notice of. The
best time for viewing the progress of nimbi-
26 OF CLOUDS. CHAP. 1. §8.
fication is in stormy weather; cumuli may
then be seen rising into mountains and
becoming cumulostrati, while long strata of
cirrostratus permeate their summits; and
the whole phenomenon has the appearance
of a range of mountains, transfixed by the
mighty shafts of giants. After having exist-
ed some while in this form, they become
large and irregular, and they get darker by
intensity, till all seem concentrated in a
dense black mass, with a cirrose crown
extending from the top, and ragged cumuli
entering from below; and eventually the
whole resolves itself into rain.”
Having in this section given a sketch of
the modifications, and of the principal cir-
cumstances which relate to their formation
* Previous to the coming up of a storm, a dead calm,
which may have for some time existed, is followed by a
gale. The approach of a storm, thus ushered in by wind,
is admirably described by Virgil:
Qualis ubi ad terras abrupto sidere nimbus
It mare per medium; miseris heu praescia longe
Horrescunt corda-agricolis: dabit ille ruinas
Arboribus stragemque satis, ruet omnia late
Antevolent sonitumque ferunt ad littora venti.
Wirg. Aeneid. xii. 451.
Char, 1.59. OF CLOUDS. 27
and peculiarities, I proceed in the next to a
further examination of the same subject.
SECTION IX.
By what has been said above, it appears
that, according to Mr. Howard's theory,
the origin of clouds is from the surface of
the earth and waters. That the vapour up-
raised by the accession of the diurnal tem-
perature, in the manner described, is con-
densed into a visible cloud, either by cold,
or by the air, from other causes; losing its
power of holding so much water in solution
as before; or by the joint influence of these
causes. That cumuli are the immediate re-
sult of this process; and that in the evening,
when the heat is diminished, the air deposits
its vapour again in the form of dew, which
gravitates to the ground, becoming more
dense as it approaches the earth, because
the lower atmosphere is now the coolest;
and finally lodges on the surface of the
herbage, or of the ground, where it awaits
the reascending sun to be again evaporated.
Cumuli also are represented to be dispersed,
ſº * ÖF CLOUBS. CHAP. T., 35.
and their constituent particles to come to
the ground in the same manner:* Accord-
ing to the same theory, it appears that the
other modifications are also the consequence
of vapour carried up into the atmosphere,
while their peculiarities are more imme-
diately effected by the agency of the electric
fluid.
The conclusion of Mr. Howard's theory, as
it is given in Rees's Cyclopaedia, is so good,
that I shall adopt it as a termination to this
section. r
“We shall conclude with a brief review
of the modifications ascending from the
STRATUS, formed by the condensation of
vapour on its escape from the surface to the
CUMULUs, collecting its water in the second
stage of its ascent, both probably existing
by virtue of a positive electricity. From
these proceeding threugh the partially con-
ducting CUMULosTRATUs to the CIRRoSTRA-
Tus and CIRRocumulus; the latter positively
charged, and considerably retentive of its
* Although the reason of their sinking may be the
destruction of the vapour plane in the evening, yet some
other cause must exist for the cumulus to disperse and
fall in diffused mist, or dew : see the next Chapter.
CHAP. 1. § 10. OF CLOUDS. 29.
sº charge; the former less perfectly insulated,
and, perhaps, conducting horizontally: we
arrive thus at the region where the CIRRUs,
light and elevated, obeys every impulse or
invitation of that fluid, which, while it
finds a conductor, ever operates in silence;
but which embodied and insulated in a
denser collection of watery atoms, sooner or
later bursts its barrier, leaps down in light-
ning, and glides through the NIMBUs from
its elevated station to the earth.”
SECTION X.
Though the above theory appears very
plausible, and is certainly in many respects
accurately correct, yet there are other theo-
ries which are opposed to it in many parti-
culars, and which seem likewise to have
some pretensions to credit. I shall proceed
next to mention some of these, and compare
them with that of Mr. Howard. It is con-
tended by some that the dew does not fall,
but, on the contrary, rises: the earth, it is
said, retains the heat of the day longer than
the air immediately above it: that evapora-
50 OF CLOUDS. CHAP. 1. $ 10.
tion being greater, according to the propor-
tion of heat which the water bears to the
air into which it evaporates, there becomes
a considerable evaporation from the earth
and waters in the evening, which is con-
densed again in the cold air. I readily allow
that this may take place; but it does not
appear to me to militate against what has
been advanced in the preceding Section.
Evaporation may still be going on from
below, while there is a precipitation from
above; and thus we may account for the
stratus not always resting on the ground,
but frequently beginning at a small-distance
from it, or increasing in density for some
feet upwards, there being a sort of shallow
vapour plane preserved so long as the heat
continued to be slowly transmitted from the
earth.
M. De Luc asserts that clouds are not the
constant result of evaporation from the
earth. He accounts for them by supposing
that the air is decomposed by the sun's rays,
so as to deposit aqueous particles, which
become clouds. If this be admitted to take
place, it does not argue against the ascent
of vapour: and whether the watery parti-
CHAP. 1. § 10. OF CLOUDS. 31
cles arise immediately from the ground, or
are deposited by the air, they may equally
be supposed capable of becoming cloud,
when operated upon by the nubific principle
which is believed to be electrical: indeed,
these two processes may co-operate to the
production of clouds, so that, if this hypo-
thesis be advanced against Mr. Howard's
theory, it cannot be regarded as constituting
a valid objection.*
* The following extract will, perhaps, furnish to the
reader a more perfect idea of Mr. Howard's theory of the
origin of clouds:
“On the remote and universal origin of clouds there
can be but one opinion—that the water of which they
consist has been carried into the atmosphere by evapora-
tion. It is on the nature of this process, the state in
which the vapour subsists for a time, and the means by
which the water becomes again visible, that the greatest
diversity of opinion has prevailed.
“The chemical philosopher, seduced by analogy, and
accustomed more to the action of liquids on solids, natu-
rally regards evaporation as a solution of water in the
atmosphere, and the appearance of cloud as the first
indication of its precipitation; which becoming afterwards
(under favourable circumstances) more abundant, pro-
duces rain. The theory of Dr. Hutton goes a step
further, assumes a certain rate of solution differing from
that of the advance of temperature by which it is effected,
and deduces a general explanation of clouds and rain.
32 OF CLOUDS. CHAP. i. 310.
It is said again, that nimbi have been ... •
observed to take place without the pre-
from the precipitation which, according to his rule,
should result from every mixture of different portions of
saturated air. The fundamental principle of this theory
has been disproved in an essay heretofore presented to
the society,” and which was written under the opinion,
at present generally adopted by chemists, that evapora-
tion depends on a solvent power in the atmosphere, and
follows the general rules of chemical solution.
“The author has since espoused a theory of evapo-
ration which altogether excludes the abovementioned
opinion (and consequently Dr. Hutton's also,) and con-
siders himself in a considerable degree indebted to it for
the origin of the explanation he is about to offer. It will
be proper, therefore, to state the fundamental proposi-
tious of this theory, with such other parts as appear
immediately necessary, referring for mathemetical de-
monstrations and detail of experiments to the work
itself, which is entitled “Experimental Essays on the
Constitution of mixed Gases; on the Force of Steam or
Vapour from Water aud other Liquids in different Tem-
peratures, both in a Torricellian Vacuum and in Air;
- on Evaporation; and on the Expansion of Elastic Fluids
by Heat. By John Dalton.”—See Memoirs of the
Literary and Philosophical Society of Manchester, vol.
v. part 2.-The propositions are as follow:
* 1. When two elastic fluids, denoted by A and B,
are mixed together, there is no mutual repulsion amongst
their particles; that is, the particles of 4 do not repel
* See Phil. Mag, vol. xiv. p. 55.
CHAP. l. $ 10. OF CLOUDS. 33
currence of other modifications; but I have
seen it no where proved, that after their
those of B, as they do one another. Consequently, the
pressure or whole weight upon any one particle arises
solely from those of its own kind.
* 2. The force of stream from all liquids is the same
at equal distances above or below the several temperatures
at which they boil in the open air; and that force is the
same under any other pressure of another elastic fluid as
it is in vacuo. Thus the force of aqueous vapour of
212° is equal to 30 inchcs of mercury; at 30° below, or
182°, it is of half that force; and at 40° above, or 252°,
it is of double the force: so likewise the vapour from
sulphuric ether which boils at 102°, then supporting 30
inches of mercury, at 30° below that temperature it has
half the force, and at 40° above it, double the force :
and so on in other liquids. Moreover, the force of
aqueous vapour of 60° is nearly equal to half an inch
of mercury when admitted into a Torricellian vacuum;
and water of the same temperature, confined with per-
fectly dry air, increases the elasticity to just the same
amount. A
* 3. The quantity of any liquid evaporated in the
open air is directly as the force of stream from such
liquid as its temperature, all other circumstances being
the same.’
The following is part of the Essay on Evaporation:
“When a liquid is exposed to the air, it becomes gra-
dually dissipated in it; the process by which this effect is
produced we call evaporation.
“Many philosophers concur in the theory of chemi-
cal solution: atmospheric air, it is said, has an affinity
D
34 OF CLOUDS. CHAP. 1. $10.
formation rain has gone on without a cir-
rose crown on the upper part of the nimbus.
for water; it is a menstruum in which water is soluble
to a certain degree. It is allowed, notwithstanding, by
all, that each liquid is convertible into an elastic vapour
in vacuo, which can subsist independently in any tem-
perature: but as the utmost forces of these vapours are
inferior to the pressure of the atmosphere in ordinary
temperatures, they are supposed to be incapable of exist-
ing in it in the same way as they do in a Torricellian
vacuum: hence the notion of affinity is induced. Ac-
cording to this theory of evaporation, atmospheric air
(and every other species of air for aught that appears)
dissolves water, alcohol, ether, acids, and even metals.
Water below 212° is chemically combined with the
gases; above 212° it assumes a new form, and becomes
a distinct elastic fluid, called steam: whether water first
chemically combined with air, and then, heated above
212°, is detaehed from the air or remains with it, the
advocates of the theory have not determined. This
theory has always been considered as complex, and at-
tended with difficulties: so much that M. Pictet and
others have rejected it, and adopted that which admits
of distinct elastic vapours in the atmosphere at all tem-
peratures, uncombined with either of the principal con-
stituent gases, as being much more simple and easy of ex-
plication than the other; though they do not remove
the grand objection to it, arising from atmospheric
pressure.”
“On the Evaporation of Water below 212°.
“I have frequently tricd the evaporation at all the
1.
Chari. s.10, of CLOUDs. 35
I have noticed the spontaneous formation
of nimbí more than once. Of this I shall
temperatures below 212; it would be tedious to enter
into detail of all the experiments, but I shall give the
results at some remarkable points. In all the high tem-
peratures I used the vessel abovementioned,” keeping
a thermometer in it, by which I could secure a constant
heat, or at least keep it oscillated within narrow limits.
º “The evaporation from water of 180° was from 18
to 22 grains per minute, according to circumstances; or
about one-half of that at 212°.
“ At 164° it was about one-third of the quantity at
the boiling temperature, or from 10 to 16 grains per
“At 152°it was only one-fourth of that at boiling,
or from 8 to 12 grains, according to circumstances.
“The temperature of 144° affords one-fifth of the
effect at boiling; 188° gave one-sixth, &c. -
“Having previously to these experiments determined
the force of aqueous vapour at all the temperatures under
212°, I was naturally led to examine whether the quan-
tity of water evaporated in a given time bore any pro-
portion to the force of vapour of the same temperature,
and was agreeably surprised to find that they exactly cor-
responded in every part of the thermometric scale; thus
the forces of vapour at 212°, 180°, 164°, 152°, 144°,
and 138°, are equal to 30, 15, 10, 74, 6, and 5 inches
of mercury respectively; and the grains of water evapo-
rated per minute in those temperatures were 30, 15, 10,
* This refers to experiments on the evaporation of
water at 212° for which see the Essay. -
- D 2
36 OF CLOUDS. CHAP. 1. $10.
say more hereafter, when I shall attempt.
further to illustrate these subjects by a detail
7}, 6, and 5, also ; or numbers proportional to these.
Indeed it should be so from the established law of me-
chanics, that all effects are proportional to the causes
producing them. The atmosphere, it should seem, ob-
structs the diffusion of vapour, which would otherwise
be almost instantaneous, as in vacuo; but this obstruc-
tion is overcome in proportion to the force of the vapour.
The 6bstruction, however, cannot arise from the weight
of the atmosphere, as has till now been supposed; for
then it would effectually prevent any vapour from arising
under 212°: but it is caused by the vis inertiae of the
particles of air, and is similar to that which a stream of
water meets with in descending amongst pebbles.
“ The theory of evaporation being thus manifested
ſrom experiments in high temperatures, I found that if
it was to be verified by experiments in low temperatures
regard must be had to the force of vapour actually exist-
ing in the atmosphere at the time. For instance, if
water of 59° were the subject, the force of vapour of
that temperature is 1-60th of the force at 212°, and one
might expect the quantity of evaporation I-60th also:
but if it should happen, as it sometimes does in summer,
that an aqueous atmosphere to that amount does already
exist, the evaporation, instead of being 1-60th of that
from boiling water, would be nothing at all. On the
other hand, if the aqueous atmosphere were less than
that, suppose one half of it, corresponding to 39° of
heat, then theeffective evaporating force would be 1-120th
of that from boiling water: in short, the evaporating
force must be universally equal to that of the tem-
2.
Char. 1, §10. OF CLOUDS. 37
of some particular cases.—In the conclusion of
this chapter, I may observe, that if, agreeable
perature of the water, diminished by that already exist-
ing in the atmosphere. In order to find the force of
the aqueous atmosphere I usually take a tall cylindrical
glassjar, dry on the outside, and fill it with cold spring
water fresh from the well: if dew be immediately formed
on the outside, I pour the water out, let it stand a
while to increase in heat, dry the outside of the glass
well with a linen cloth, and then pour the water in
again: this operation is to be continued till dew ceases to
be formed, and then the temperature of the water must
be observed; and opposite to it in the table will be
found the force of vapour in the atmosphere. This
must be done in the open air, or at a window; because
the air within is generally more humid, than that with-
out. Spring water is generally about 50°, and will
mostly answer the purpose the three hottest months in
the year; in other seasons an artificial cold mixture is
required. The accuracy of the result obtained this way
I think scarcely needs to be insisted upon. Glass, and
all other hard, smooth substances I have tried, when
cooled to a degree below what the surrounding aqueous
vapour can support, cause it to be condensed on their
surfaces into water. The degree of cold is usually from
1 to 10 below the mean heat of the 24 hours; in summer
I have often observed the point as high as 58° or 59°,
corresponding to half an inch of mercury in force; and
once or twice have seen it at 62°; in changeable and
windy weather it is liable to considerable fluctuation; but
this is not the place to enlarge upon it.
“ For the purpose of observing the evaporation in
s8 OF CLOUDs,
* HAP. :1 , § ið,
to the experiments of modern chemists, the
conversion of fluids into elastic vapour is at-
atmospheric temperatures I got two light tin vessels, the
one six inches in diameter and half an inch deep, the
other eight inches diameter and three-fourths of an inch
deep, and made to be suspended from a balance. When
any experiment, designed as a test of the theory, was
made, a quantity of water was put into one of these
(generally the six-inch one, which I preferred,) the whole
was weighed to a grain; then it was placed in an open
window or other exposed situation for 10 or 15 minutes,
and again weighed to ascertain the loss by evaporation;
at the same time the temperature ofthewaterwas observed,
the force of the aqueous atmosphere ascertained as above,
and the strength of the current of air noticed. From a
great variety of experiments made both in the winter and
summer, and when the evaporating force was strong and
weak, I have found the results entirely conformable with
the above theory. The same quantity is evaporated with
the same evaporating force thus determined, whatever
be the temperature of the air, as near as can be judged;
but with the same evaporating force, a strong wind will
double the effect produced in a still atmosphere. Thus,
if the aqueous atmosphere be correspondent to 40° of
temperature and the air be 60°, the evaporation is the
same as if the aqueous atmosphere were at 60° of tem-
perature and the air 7 2°; and in a calm air the evapora-
tion from a vessel of six inches in diameter in such cir-
cumstances would be about 9 of a grain per minute, and
about 1.8 grains per minute in a very strong wind; the
different intermediate quantities being regulated solely by
the force of the wind.

CHAP. i. 610. OF CLOUDS. * 39
tended with a loss of heat; the vapour from
water, by rendering the upper atmosphere
“Having quoted so much of this essay as may suf-
fice to exhibit the principles on which we shall proceed,
it may be useful, before we do this, to recapitulate the
following circumstances respecting the atmosphere of
aqueous gas, or (for brevity) the aqueous atmosphere.
“ 1st. It is supplied by the process of evaporation,
which by this theory appears to be reduced to the imme-
diate union of water with caloric into a binary compound,
aqueous gas. t
“ 2dly. The supply of vapour (by which term, for the
purposes of meteorology, we may denote aqueous gas,)
is regulated by the following circumstances:–1. Tempe-
rature of the evaporating water, being greater as this is
higher, and vice versá. 2. Quantity of surface exposed.
Since it is from the surface only of the mass that the
vapour in common cases can escape, the supply is in
direct proportion thereto. 3. Quantity of vapour already
subsisting in the atmosphere: the evaporation being less
(with equal temperature and surface) in proportion as this
is greater, and vice versä. -
“ 3dly. The vapour thus thrown into the atmosphere
is diffusible therein by its own elasticity, which suffices
for its ascent to any height in a perfect calm. Yet,
as in this case the inertia of the particles of air con-
siderably resists its diffusion, so in the opposite one
of a brisk current, the vapour, by the same rule, must
in some measure be drawn along with the mass into
which it enters. . -
“4thly. The quantity of vapour which, under equal
pressure, can subsist in a given mass of air, will be
40 OF CLOUDS. Chap. 1. $10.
into which it ascends cooler than it was
before, also renders it less capable, agreeable
greater as the common temperature is higher, and vice
2)6?"Sø.
“Aqueous vapour is the only gas contained in the
atmosphere which is subject to very sensible variations in
quantity. These variations arise from its attraction for ,
caloric being inferior to that of all the others. Hence
when a cold body, such as the glass of water in the
experiment above quoted, is presented to the atmosphere,
the other gases, composing the latter, will only be cooled
by it (and that atall known temperatures;) but the vapour,
after being more or less cooled, will begin to be decom-
posed, its caloric entering the body while the water is
left on the surface. *
“ The formation of cloud is in all cases the remote
consequence of a decomposition thus effected, except that
the caloric escapes, not into a solid or liquid, but into the
surrounding gases.
“ Dew is the immediate result of this decomposition.
The particles of water constituting it are, singly, invi-
sible, on account of their extreme minuteness. The
approach of dew is, nevertheless, discoverable by a
dark hazy appearance, verging from purple to faint red,
extending from the horizon to a small distance upwards,
and most conspicuous over valleys and large pieces of
water.
“The theory of dew seems to be simply this:—during
the heat of the day a great quantity of vapour is thrown
into the atmosphere from the surface of the earth and
waters. When the evening returns, if the vapour has
not been carried off in part by currents, it will often
CHAP. 1. § 10. OF CLOUDS. 41
to Mr. Howard's theory, of containing so
much aqueous gas in solution, which thus
contributes to effect its own condensation
into clouds: by which process there is pro-
duced again an increase of heat; and by
this means the degree of temperature is in
Some measure restored."
happen that more remains diffused in the general atmo-
sphere than the temperature of the night will permit
to subsist under the full pressure of the aqueous atmo-
sphere. A decomposition of the latter then commences,
and is continued until the general temperature and
aqueous pressure arrive at an equilibrium, or until the
returning sun puts an end to the process. The caloric
of the decomposed vapour goes to maintain the general
temperature; while the water is separated in drops,
which, minute as they are, arrive successively at the
earth in the space of a few hours. That the ordinary
production of dew is by a real descent of water from the
atmosphere, and not by decomposition of vapour on
surfaces previously cooled (as in the experiment already
mentioned) any one may readily be convinced by ob-
serving in what abundance it is collected by substances
which are wholly unfit to carry off the requisite quantity
of caloric for the latter effect.”—Phil. Mag. Sep. 1803.
4? ' ' of CLOUDs, Chan 2.
CHAPTER II.
FURTHER OBSERVATIONS ABOUT THE PECULI.
ARITIES OF THE CLOUDS.
In the foregoing chapter I have given a
hasty and imperfect sketch of Mr. Howard's
theory of the origin, suspension, and de-
struction of clouds. I shall next proceed
to examine further the various appearances
which the different modifications present in
the progress of their formation, changes, and
destruction; the influence which they ap-
pear to have on each other, and the con-
nexion observable between their peculiarities
and other atmospheric phaenomena. The
reader will see how far these phaenomena
are reconcileable with what has been already
said in the above chapter. In investigating
the causes of these changes, I have selected
such few cases as appeared necessary to illus-
trate them, and for further particulars I refer
to the Appendix at the end of the volume,
and to my journal in the Philosophical Maga-
GHAP. 2. § 1. OF CLOUDS. 43
zine. In this journal, it may be said, I have
been too minute in the detail of appearances.
But where effects are intricate and complex,
an accurate detail of them appears the only
thing that can lead to a knowledge of their
particular causes.
SECTION I.
Of the Varieties of the Cirrus.
I HAVE already said that the cirrus was by
no means uniform in its appearance; but, on
the contrary, that it exhibited a very great
variety of figure, both while it remained a
determinate cirrus, and when passing to the
other modifications. That these varieties
are the effect of a variation in the cause of
the cloud, cannot be doubted; many of them
are attendant upon particular kinds of wea-
ther; and an accurate examination of them,
compared with other coexisting phaeno-
mena, seems likely to throw additional light
on the nature of the peculiar office which the
cirrus performs; namely, that of conducting
the electric fluid.
When the weather is dry, the cirrus has
44 OF CLOUDS. CHAP. 2. § 1.
more of a fibrous texture then when it is
damp; and whatever may be its figure,
whether comoid, linear, or filiform, its ex-
tremities are always fine evanescent points.
This is a fact very conformable to our pre-
sent idea of its nature. For when sur-
rounded by dry air, which is an electric,
there is not a free passage for communi-
cation; and the cirrus necessarily assumes
that form which is best calculated for con-
ducting, the evanescent terminations being
probably points for the transmission of the
fluid, and they are directed towards that
part of the sky with which the electric com-
munication is to take place. t
On the 30th of August, 1811, the air
being very dry, according to the hygrometer,
the cirri were spread about in a lofty region;
they were of a fibrous texture, one end ter-
minating in transmitting points, the other
frequently more massy; they passed on
gently with the wind, in succession; by the
evening none were to be seen. Cumuli also,
formed during the day in a lower atmo-
sphere, moved along in the lower current,
and likewise disappeared at night. The
dryness of the air might be the reason why
CHAP. 2.51. OF CLOUDS. 45
these two kinds of clouds did not affect each
- other, so as to produce cumulostratus and
nimbus, by their union. ..º.
In wet weather, when the air is damp, the
cirrus, which is seen in the intervals of the
rain, is ill defined, and often of a sort of
plumose figure; and it has less of the fibrous
structure: this may be attributed to its being
surrounded with moister air, which being a
conductor, though an imperfect one, there
is not the same necessity for the cirrus to be
drawn out into fine transmitting points; as
the fluid can fly off more generally from all
parts of it. Cirri of this kind are generally
of short duration, and have a great tendency
to change into the other modifications; there
is often a haziness in the atmosphere when
they appear, and they are frequently soon
followed by rain. They seldom appear in
fair dry weather; and if cirri, which have
been previously fibrous, put on the plumose
and indefinite character, a change to wet
weather may be expected. All these are
circumstances which corroborate the opinion,
that the humidity of the circumjacent air is
the cause of this kind of feature of the cir-
46 OF CLOUDS. CHAP, 2, § 1.
rus, and agree very well with the nature of
the office already assigned to it.
I have almost always found the fibrous
cirri to be accompanied by dry air. . But
there are rare exceptions to this rule. The
upper air may, however, be tolerably dry,
while the under air is moister, which may
account for the occasional appearance of
cirri of fibrous texture above, at a time
when the hygrometer indicates a humid
atmosphere below.
The plumose cirrus often appears when
the sky is deep blue, and the cirrus of fibrous
structure sometimes appears when it is pale
coloured. But the intensity of the blue of
the sky does not seem to depend on the
dryness of the air; nor the paleness, on its
moisture. In the intervals of showers the
intensity of the blue is often the greatest.*
While I am now writing, I observe out of
my window abundance of fibrous cirri in a
sky rather pale than otherwise. During the
abundance of cirri I have sometimes per-
* Sir Isaac Newton somewhere observes that the deepest
blue sky happens just at the change from a dry to a moist
atmosphere.
‘CHAP. 2. § 1. QF CLOUDS. 47
ceived the sky particularly pale; which, on
minute examination, have been found to be
caused by innumerable fine fibres of cirrus
laying very close together.
There is a variety of the cirrus, called in
£incolnshire the Sea Tree, which has some-
what of the plumose structure, and generally
precedes rain. Its figure gives a faint resem-
blance to that of a tree, whence it derives
its name, one end being a compact kind of
trunk, from which fibres diverge and ramify
into confused or plumose branches.*
The obliquely descending bands of cirrus,
before mentioned, which occur chiefly in fair
warm weather with light gales of wind, are
not always detached. I have seen them pro-
ceeding from other clouds, and sometimes
connecting two distant massesofcloud, which
in this case have always been undergoing a
change of appearance, reconcileable with the
idea of a change in their electric state.
The detached comoid cirri, called Mares'
Tails, are seldom very much elevated, par-
* By plumose, is meant a figure which gives the idea
of the folded ends of a plume of feathers. The sea tree
sometimes looks like many of these plumes diverging from
one stem.
48 OF CLOUDS. CHAP. 2, § 1.
ticularly those which ramify vertically. Their
presence is well known to be an indication
of wind; and when their transmitting ter-
minations have a decided direction, the sub-
sequent wind has been often found to blow
from the quarter to which they have pre-
viously pointed. This circumstance seems
difficult of explanation. For if we suppose
a current of air, differently electrified, to
precede the more violent and sensible wind
that is to follow, with which the cirrus com-
municates its electricity by means of these
pointing fibres; how comes the cirrus itself,
though apparently stationary, to be actually
moving on slowly in an opposite direction ?
which I have observed to be the case: and,
indeed, cirri in general move along with
their tails either foremost or aslant. If
these cirri, then, be moved along by the
current of air, it cannot be imagined that
there can be a current of differently elec-
trified air meeting them, which should
draw out their tails into transmitting points.
For if two currents meet, which ever was
strongest would counteract the other, and
would move the cirrus at the rate of the
difference of the two velocities. It is dif-
CHAP. 9, § 4. OF CLöUīj9. 49
ficult, too, to suppose that there can be a
tide of electricity moving against the wind;
but it is possible that the cirrus may not be
carried forward by the mechanical impulse
of wind. The same electric attraction, which
may draw out its cirriform tail for the pur-
pose of equalization, may be supposed, fur-
thermore, to move slowly the whole mass
in the same direction. I never could quite
satisfy myself on this point. Perhaps the
electric attraction, which draws out the cir-
rus into transmitting points, exercises its
power quite independent of the wind then
blowing; for these cirri sometimes move in
a direction very different from the direction
of their tails: besides, the cirrus has been
observed to continue moving on, in the same
direction, while the tails have veered round
toward another quarter.”
There is sometimes a kind of motion ob-
servable in the cirrus, which I have never
* Whether by the fleeces of wool, which Aratus, Vir-
gil, and Lucretius speak of, as being carried across the
welkin in rainy weather, were intended these comoid
cirri, cirrostrati, cirrocumuli, or large flocky scud, is
uncertain. They intended, however, to describe the pe-
culiar clouds which accompany variable weather,
E
50 OF CLOUDS. CHAP.2, $1.
noticed in any other cloud, which it is some-
what difficult to describe, and which, when-
ever I have seen it, has happened in a cirrus
of a particular kind; namely, in one which
has a sort of plumose extremity, with a long
fibrous body, and a fine transmitting pointed
tail.” The plumose head, which under these
circumstances is clearer and rather more
fibrous than usual, together with the body,
seem all in motion, as if every particle was
alive. This motion may be compared to
that of a piece of cheese full of mites, which
seems agitated in every point, without ever
materially changing its place. This was
remarkably conspicuous in some cirri, which
I saw from Farningham, in Kent, about 6
o'clock in the evening of the 16th of July,
1811. They pointed nearly to the East.
The weather which preceded them was varia-
ble, with some showers, and they were suc-
ceeded by several days of fair dry weather
with various clouds, at the end of which
time happened a hard thunderstorm about
three in the morning. Can this motion pos-
sibly be the effect of an effort on the part of
* Plate I. Fig. 2.
CHAP, 2, $1. of CLOUDs. *A. &l
the electrified particles of the cloud, to equa-
lize their own electricity with that of the
air?" or may there be some disturbance in
the electricity within the cloud, from other
causes Sometimes portions of the cloud
seem lightly agitated, as if by partial but
gentle draughts of wind. Can the motion
alluded to be caused by the evolution of any
air generated in the cloud
When the cirrus ceases to conduct, it
changes its form, and becomes some other
cloud, as has been said: thus, sometimes a
sky full of cirrous streaks, after a while
becomes overspread with a milky whiteness.
This is a sort of change to cirrostratus,
which often ends in rain.” The cirri how-
ever frequently change to the cirrocumulus;
and in the progress of the change the cirrous
fibres seem to shoot out laterally into trans-
.* The Abbé Bertholin probably alludes to the cirrus,
as well as to scudlike cumulus, and other transitory fea-
tures of the modifications, which appear in the intervals
of showers, when he speaks of the “Lambeaux et frag-
ments de nuages qui sont comme disseminés dans les
differentes regions de l’air, les uns somt plus hauts (cirri,
&c.) les autres plus bas (scud, &c.) et flottent au gre des
vents de divers cétés.” He speaks of them as vehicles of
the electric fluid, and as useful in conveying away the
E 2
52. OF, GIOUDS. CHAP, 2, § 2,
verseandintersectingstreaks; they first change
to cirrocumulus at their points of intersec-
tion, which thicken, approach to the orbieu-
lar form, and seem like centres from which
fibres eradiate; thus a sort of filiform cir-
rocumulus is effected, which either goes on
changing to a more perfect feature of that:
cloud, changes again to cirrus or to cirro-
stratus, or evaporates. It often happens that,
as the cloud is gently moving on, the spec-
tator has not an opportunity of watching it
throughout all its metamorphoses.
SECTION II.
Of the Varieties of the Cirrocumulus.
THE permanent features of any cloud.
should be distinguished from those which
are only transitory, or which the cloud ex-
hibits in the progress of its change from
matter of lightning, which would otherwise be oftener
embodied in large clouds, and strike the earth with ter-
rible violence. Thus he seems to have had some faint
notion of an office performed by clouds, which more
recent discoveries have ascribed to the cirrus. See Ber-
thol. De l’Elec. Met. t. II. p. 113.
CHAP.2. §2. GF CLOUDS. £3
one modification to another. I have beforé
noticed, that in the change from the cirrus
to the cirrocumulus, a number of appear-
ances present themselves, which cannot be
referred to either. They generally, however,
end in a determinable Imodification, which I
call its permanent form; and in which it
generally remains for some time, and then
evaporates, or changes again. The perma-
ment features of the cirroeumulus vary at
different times, and the varieties are con-
nected with particular states of the atmo-
sphere. In fine warm weather in summer,
particularly towards evening, the nubeculae
which compose this cloud are often large,
well defined, and separate from each other:
the whole sky is sometimes replete with
them. This feature is often the forerunner
of fine and wholesome, after a long con-
tinuation of wet and variable, weather: it
is strikingly contrasted to that variety of
cirrocumulus which is composed of very
diminutive nubeculae; by which the sky
seems sometimes peppered, if I may so
express myself, with innumerable little round
white specks, which are sometimes of so
54 OF CLOUDS. Char. 2, $2.
light a texture as to be almost transparent.
There is a sort of cloud of this latter sort,
which, though its nubeculae preserve some-
thing of the round shape of the cirrocumulus,
has the light and flimsy appearance, and
almost transparency of cirrostratus of one
kind, and it becomes very difficult to know
what name to give it. Refer to the tenth
Section of this Chapter.
In stormy weather, previous to thunder, a
cirrocumulus often appears, whose compo-
nent nubeculae are very dense and compact
round bodies in very close arrangement. The
prevalence of this feature, particularly when
accompanied by cumulostratus, is a sure
indication of an approaching storm.*
I have often had occasion to mention the
cirrocumulus, as being very generally a fore-
boder of warmth. In Germany these clouds
…”
* If the cirrocumulus, as Mr. Howard supposes, is a
cloud positively charged and very retentive of it, the
intensity and decided character of this feature indicates
the very high state of its charge; this notion agrees very
well with the circumstance of its accompanying thunder-
storms. Are not the densest cumulostrati formed from
its conjunction with the cumulus?
CHAP. 2.58. of CLOUDs. 55
are called little sheep: and Professor Heyne
has a note on them in his edition of Virgil.”
And our poet Bloomfield has likewise com-
pared them to a flock at rest, in a passage
already cited. In certain weather cirrocu-
mulus rapidly forms in different places in the
sky, and soon subsides again, asis mentioned
in another place.
SECTION III.
Of the Varieties of the Cirrostratus.
It would be impossible to convey to the
, reader a complete detail of all the varieties
of any cloud; for, as in every other natu-
ral production, no two appear exactly simi-
lar in all particulars of shape, size, situation,
&c. But as the clouds, countless and innu-
merable as their shapes and sizes are, have a
tendency, under certain circumstances at pre-
sent not precisely known, to break out into
some of the seven distinct modifications; so
each modification has certain particular varie-
* Heyne's Virgil, 4 vols. 8vo. Lips, 1803, ad Georg.i.
97, p. 314 of vol. i. - *
§6. -OF CLOUDS, CHAP, 2, § 3,
ties into which it forms itself on different
occasions, and the meteorological speculator
may be assisted, by having some of the prin-
cipal of these pointed out to him.
The varieties of the cirrostratus are nume-
rous; but throughout all of them this cloud
preserves its distinguishing characteristics;
namely, shallowness, and extent in propor-
tion to the quantity of its substance; gene-
rally a horizontal position, and a tendency to
alter its form and to subside. It is often
lower down than a cirrus in the same sky,
and a change from that cloud to cirrostratus
is usually attended with a diminution of its
altitude, a greater degree of density in its
fibres, and in a more regularly horizontal
position. The plane sheets of cirrostratus
are the most simple of its forms: when
these are not extensive, and are seen in the
distance, they often look like a dense streak
drawn along near to the horizon; but
distinguishable from streaks of cirrus.
There are some peculiar appearances of this
kind, which, swelling somewhat in the mid-
dle, and seen below a more thin and exten-
sive sheet of cloud, give the idea of the
back of a great dolphin rising out of the
CHAP, 2,53. , OF CLOUDS. : 57,
ocean, ; It is in the thin and extensive sheets.
of this cloud, covering the welkin before its
condensation into water, that the halo ap-
pears.” It is this cloud which, under some
unknown circumstances of atmospheric
change, first in a 'diffused form obscures
the sky, giving the sun, moon, or stars that
dim light, and those peculiar refractions,
spoken of in another place, and which often
eventually becomes nimbiform, and ends in
gentle and continued rain. The sun often
sets apparently shrouded in a dense feature
of this modification, and this is a sure indi-
cation of a wet morning. But let us turn to
more elegant varieties of cirrostratus, which
sometimes appear in longish irregular spots
or in bars in close horizontal position.f Fea-
tures of this kind are frequently of short dura-
tion, and move along very slowly in a high
atmosphere, and appear subsiding by degrees;
while perhaps other beds of it are forming
in other places: a feature much like this
appears in the intervals of showers. There
* See Chapter III. + Pl. II. Fig. 2.
f What is called the mackerelback sky often consists
of this feature spread over a large portion of the firma-
ment: but a sort of cirrocumulus, in like manner spread
aloft, likewise receives this whimsical appellation.
58 OF CLOUDS. Char. 2, $4.
also appears in variable weather, and before
storms, a feature of cirrostratus, like the
cyma of architecture.* I have seen cirro-
stratus which did not lie, as it usually does,
in a horizontal plane. A feature occurred
on the 5th of March, 1810, in the north
east, which was a long, tapering, inclined,
and curved column of dark lakecoloured
specks; above it were cirri scattered about
like loose hay. But to describe the cirro-
stratus in all its varieties of mottles, specks,
streaks, and lines, would swell too much this
chapter, and the meteorologist must observe
them for himself.
SECTION IV.
Of the Varieties of the Cumulus.
CUMULI vary in size and in the regularity
of their forms; they have all the tendency to
assume an irregular hemispherical figure:
those which attend fair settled weather, which
form soon after sunrise, become large, and
inosculate into extensive masses in the middle
* Pl. III, Fig. 2. ' -
CHAP. 2. §4. OF CLOUDS. 59
of the day, and subside in the evening, are
of the most regular shape. When they
increase rapidly, and become more irregular,
with fleecy bases, they will soon be cumu-
lostrati, and are to be considered as indicat-
ing variable or wet weather: in this case
they are lower down in the air, and of den-
ser appearance. In the intervals of, and
before showers, I have seen them very large,
and yet moving along in the wind, like
immense hemispheres of cloud, dense in the
middle, with silvery summits, and constantly
tending to become cumulostratus, and to
reproduce the showers; which, when they
last long, are nourished by dark flocky
cumuli, entering into the raining nimbus
from below. See Pl. W. Fig. 2.
Some of these little cumuli are not so fleecy
as the rest; they are more compact in form,
and, flying along rapidly between the
showers, are considered as a foreboding of
their return, and are called by the vulgar
water waggons. The cumuli before keen
March showers of snow, with North and East
winds,have that look of transparency, and that
definite though rugged edge, described in ano-
ther place as happening also to cumulostratus.
4.
50 OF CLOUDS. CHAP. 2. $4.
Cumuli have sometimes appeared as it were
tuberculated, and, though of their usual he-
mispherical sort of form, to be composed of
numerous eminences, or lobes of cloud. I
have not observed what peculiarities of wea-
ther these cumuli accompany,
It is curious to watch the formation of
cumuli in a morning, and trace them, when
it is possible, from the minute specks of
cloud which, here and there, seem to form
out of the atmosphere, to those large
masses which move majestically along in
the wind, and convey water from place to
place for the irrigation of the earth. In fair
weather, soon after sunrise, a small cloud
appears; this increases, others form near it,
and they fall into one another as if attracted:
a large mass is at length upraised, and then
all the smaller ones which form in its neigh-
bourhood are soon lost, while the large one
is augmented; and the spectator, though he
seldom sees it in actual congression, feels no
doubt that the disappearance of the smaller,
and augmentation of the larger cloud, is
owing to the larger mass having attracted
the smaller into itself. It becomes a ques-
tion however, why the small clouds are lost
3
CHAP, 2, §4. OF CEOUDS. ët
to appearance before they are quite drawn
into the larger one * Possibly when the small
cloud is very near, or most of its vapours
drawn away, the rest rush with velocity into
the larger; as a magnet, when it has ap-
proached a larger within a certain distance,
is forcibly and suddenly attracted to the
latter. When these ephemeral mountains
of electrified vapour have increased much,
as they do towards the middle of the day;
large ones, often inosculate, and form dense
and extensive irregular masses. Something
else besides this, however, seems necessary
to cause that density and continuity of a
base, common to several superstructures
which constitute cumulostratus.
On the dispersion of a stratus in the
morning, we often see cumuli forming at its
upper part; probably the same particles of
vapour, on the return of the vapour plane,
take the form of the cloud of day, and sub-
side in fog again in the evening. See Plate
II. Figs, 3, 4.
63 OF CLotDs. Chap.2, $5.
SECTION V.
of the W.arieties of the Stratus. - -
Though most meteorological philosophers
now concur in the general idea that dews
and fogs are the result of vapour precipi-
tated by the nocturnal decrease of tempera-
ture; yet the particular circumstances under
which dew is formed in greater or less
quantities, the time of night, and the kind of
weather when it is most precipitated, and
otherfacts relating to it, having been variously
observed by different persons, have occa-
sioned different views to be taken of their
various causes. In this section, however, I
shall confine myself to a few cursory obser-
vations on the varieties of appearance which
the stratus presents. ... •
Every body must have noticed the dif-
ference between the wet fogs (probably cir-
rostrati) which happen at all times of day,
but often in a morning,” and the white
* In Cornwall they amount to fine rain almost; they
call them the pride of the morning. Fine days frequently
follow them. - i
car. 2.55. of CLOUDs. 63
mists which wet nothing, but only leave
dew in drops on the herbage, which veil
the meadows and valleys through a summer
night, and ascend in the morning. As the
temperature decreases in autumn, the stratus
becomes thicker; the rays of the sun seem
hardly able to overcome it, and it sometimes
lasts throughout whole days; thus it gave
rise in the minds of the antients, whose
organization led them to express physical
facts metaphorically, to the fable of Phoebus
and Python.*
In the neighbourhood of great cities these
fogs, impregnated with numerous effluvia
and smoke, have a yellow appearance which
is explainable; but even in country places
the yellow fogs of November extend over
large tracts of land. *.
Dense fogs also happen sometimes, and
*Thus Phoebus, or the sun, issolicited by Cupid, or love,
the vernal influence, to court Daphne, and effect the fruits
of love in summer's productions. He boasts to the little
god of his recent victory over Python, or the fog spread-
ing his pestiferous body over the meadows.
“Quimodo pestifero tot jugera ventre prementem
Stravimus innumeris tumidum Pythona sagittis.”
. Ovid Met. II. 10.
64s of cf.ouds. CHAP. 2. $6.
appear suddenly, in different places; while
at other times fogs continue for weeks toge-
ther; such as that very thick and long fog,
though one that did not extend very high
up, which in December, 1813, ushered in the
long frost, which continued through January
and February of the present year. This fog
seems by its topological history to have tra-
velled from the West, Eastward and North-
ward over our island. See some curious
remarks about fogs, and particularly the
extraordinary fog in France of 1783, in Ber-
tholin, De l'Electricité des Meteors, Tom. II.
Chap. 4, where the observations of different
persons on this phaenomenon are duly no-
ticed.
SECTION VI.
Of Cumulostratus.
WHETHER this cloud is formed with visi-
ble conjuction of different modifications,
whether cumuli spontaneously assume its .
form, or whether it appears of itself pre-
viously, we must regard it as a stage
towards nimbus. The very dense and black
CHAP.2, $7. of CLOUDs. * §5
appearance of this cloud coming up with
the wind, and just ripening into a storm, must
be familiar to every body. Where the rain
has actually begun to fall, the blackness is
changed for a more obscure and grey colour.
This may be only the effect of the inter-
posed water of the falling rain; but if not,
and if the nimbus is effected by an intense
union of the watery particles, as I at present
believe, the intense blackness of the pre-
vious cumulostratus' must depend on some
other principle. The mountains of this
cloud, and its different appearances are men-
tioned in another place. * *
-º-
SECTION VII.
Of Nimbi which result from the visible Coales-
* * cence of distinct Clouds.
AN artificial division may be made of
nimbi into three kinds. Firstly; those which
result from the visible coalescence of distinct
clouds. Secondly; those which follow the
interfusion of moisture between distinct
clouds: and, thirdly; those which appear
F
66 of CLOUDs. CHAP. 2. $ 7.
to form spontaneously in the air, without
the precurrence of either of the above phae-
nomena. All these may, I think, be ex-
plained on the principle of the union of the
differently electrified particles of which the
clouds are composed.
If a cirrus, after it has ceased to conduct
electricity, should receive from either mass
of air, between which it may have been
conducting, an electric charge, agreeably to
the present theory it would lose its cirri-
form figure, and take on some other, perhaps
a cirrocumulus, and by degress would sink
down towards the earth. Under such cir-
cumstances, it may come into actual contact
with a cumulus rising from below by the
upward propagation of diurnal temperature.
Such a phaenomenon I have several times
witnessed; and the result has been, the
sudden commixture of both clouds into a
denser mass, or nimbus, which has resolved
itself into a gentle shower, and all has dis-
appeared; the union of the two clouds thus
apparently effecting the destruction of both.
Such showers, by visible inosculation, are
of short duration: the process is soon finish-
ed; because the nimbus, thus formed, is
CHAP. 2, $8. OF CLOUDS. 67
circumscribed by dry air, and has no source
of supply: and clearness returns, because
the superfluous aqueous particles, or such as
cannot be retaken into composition by the
air, have come to the ground in rain. When
the circumjacent atmosphere had been moist,
the process has been different, as described
in the next section.
SECTION VIII.
Qf Nimbi apparently caused by the interfusion
of Moisture between distinct Clouds.
A cumulus arising in the lower atmo-
sphere may be electrified differently from
a cirrus, or any other cloud occupying a
higher region; and these may both subside;
the upper one, perhaps, by evaporation; and
the lower by the usual vespertine descent,
without uniting and forming the compound
modifications. This appears to be frequent-
ly the case in very dry weather, when cirri
may be observed in the higher air, changing
their forms, passing to cirrocumulus and
cirrostratus, and eventually subsiding, while
F 2 ^.
63 OF CLOUDS, CHAP. 2. § 8.
cumuli sail leisurely along below. And
these appearances continue, for many days
together, without producing cumulostratus;
which, nevertheless, occasionally happens,
from the cumulus rising up and meeting with
some other cloud descending. This will
sometimes produce a nimbus, as I described
above. At other times, however, the cumu-
lostratus thus formed proceeds no further,
and even reassumes the character of simple
cumulus, and subsides in the wonted way.
These are circumstances which I have
observed to attend a dry state of the air, by
the hygrometer, etc.
Previous to rain, very different appear-
ances frequently present themselves. The
cumulus in the lower atmosphere changes
its appearance, becomes denser, irregular in
shape, and rocklike in its superstructure,
with fleecy protuberances about its base;
and, by degrees, is a complete cumulostra-
tus. While this process is going on, cirri,
cirrostrati, or cirrocumuli, which have pre-
wiously appeared above, are lost, to all ap-
pearance, as if they had suddenly evaporated.
The air will now be found damper, and
there is frequently a visible mistiness above;
3
CHAP.2, $8. OF CLOUDS. 69
and the explanation which I have to offer
for this phaenomenon is, that the humidity
of the air between the clouds affords a
means of communication between their dif-
ferent electricities; and that the cumulus,
being the largest body, draws down the
cirrus above, and is aggrandized, its previous
electric state destroyed, and its structure
altered by the change. The surrounding air
being damp, the process goes on, affecting
clouds more distant, and the result is nimbus
and rain.
A free passage for the electric fluid being
afforded by the humidity of the air, it may
readily be imagined, that the cumulus below,
and the cirrus above, differently electrified,
would mutually attract each other; and that
the cumulus, being the larger body, would
draw down the particles of the cirrus, while
it appears to be drawn upward in a pro-
portionate degree, and rises into mountains.
The sudden loss of the cirriform cloud above,
instead of a visible descent, is not at all sur-
prising; for its electric state being destroyed,
and its particles being more powerfully at-
tracted by the greater aggregate, they cease
to be held together in a body. This sug-
70 OF CLOUDS. CHAP. 2, § 8,
gests another reason for thinking that it is
not the simple attraction of aggregation
alone which keeps the particles of clouds
together in a mass. -
When the cirrus above has been very large,
I have observed the process to vary, in a
manner quite conformable to my notions of
the principles of action of the two clouds
on each other. A sort of haziness having
appeared between the two clouds, the cirrus
loses its cirriform and fibrous figure, in-
creases in density, and swells downward, to
meet the cumulus rising from below and also
changing its structure, till they have both
united and formed a nimbus. The two
clouds in this case being more nearly of a
size when the communication of their elec-
tricities took place, neither of them drew
the other into itself, while both, losing
their electric state, went on to become sepa-
rate nimbi, and united merely upon the
principle of attraction by which a nimbus is
held compact.
CHAP. 2. $9. OF CLOUDS. 7i.
SECTION IX.
of what has been called Spontaneous Nimbi-
fication.
By what has been said above, it appears
that the cause of such a union between two
differently electrified strata of cloud, is the
humidity of the interjacent atmosphere: and
this humidity, it seems, may take place either'
in consequence of the dispersion of some
cloud from a cessation of the electric actions
which kept it together in a mass, or by a
more general deposition of haze from the
oversaturated air. Either of these causes,
by affording a communication of electricity
between the differently electrified clouds,
might cause their union, and the production
of nimbus. I think this will explain the
cause of the nimbus unpreceded by other
clouds. For if the air, from unknown causes,
can so deposit watery particles, which may
be diffused through a large mass of air, if
the said large tract of air, before dry, and
consequently an electric, should have a plus
and minus state, the watery particles diffused
72 OF CLOUDS. CHAP. 2. § 9.
in it would also receive such a division of
electricity: but these electricities having now,
by the general humidity, a communication
almost as soon as formed, they might unite,
so as to form rain. This is a process which
would be comparatively slow and progres-
sive: and thus we may account for what
has been called, by some, the spontaneous
formation of nimbi; *... and, by others the
gradual condensation of the air into rain, f
which lasts whole days, and affords an
example of the more slow and gentle ope-
ration of the same causes, which, when
effected rapidly by the sudden union of
clouds, produce the more temporary and
violent phaenomena of showers and thun-
derstorms.
* M. I. A. De Luc mentions having observed this
spontaneous nimbification, unpreceded by cirri, when
he was at the top of high mountains. See some curious
observations in his “Idees sur la Meteorologie,” 2 vol.
8vo. London, 1786.
† In nimbum cogitur ačr. * --
Chap. 2.; 10. OF CLOUDS. 73
SECTION X.
Of certain Effects of the different Modifica-
tions on each other, by Approa'imation, or with
Coalescence.
It has been already stated, that the effect.
of the coalescence of two different modifica-
tions, as, for example, of cumulus with
cirrus, has been the production of the cumu-
lostratus, and finally nimbus; and also that
nimbus has appeared to result from the vi-
cinity of two different modifications, par-,
ticularly when the interfused air has been
damp. I proceed now to speak of more
transitory effects produced on clouds by the
approximation of others of a different modi-
fication. The most remarkable of these is
the conversion of cirrus or cirrostratus into
cirrocumulus, on the approach of cumulus,
or cumulostratus. On the 12th June, 1811,
the weather being showery, with clear inter-
vals, while looking out of window at Plais-
tow, in company with Mr. Howard, I ob-
served a cirrus scattered about in the East.
Cumuli were at the same time flying along
7%, OF CLOUDS. CHAP. 2. § 10.
in a lower current of air: presently, a large
cumulus passed apparently under the afore-
said cirrus, which now seemed affected by
the approach of the cumulus, and rapidly
took on the form of a sort of stellated cirro-
cumulus: the cumulus, at the same time,
increased in density, and approached more to
the nature of cumulostratus. I have several
times since seen this phaenomenon effected in
the same manner. On the 16th June, 1811,
a large mass of cumulostratus passing under
long streaks of cirrostratus, the latter gra-
dually, as the former approached, changed
into cirrocumulus. For particulais relative
to the kind of weather, state of meteoro-
logical instruments, &c. see Journal for the
above two days in Phil. Mag. Analogy
leads us to refer these phaenomena to the
operation of the different electricities of the
two clouds on each other. The effect of
large masses of cumulus on smaller ones in
their vicinity has been otherwise noticed.
The approximation of clouds toward each
other is always attended with some alteration
of their appearance. And clouds are al-
ways operating on one another and altering
each others' forms,
CHAP. 3, § 11. OF CIOUDS,
73
SECTION XI.
of Thunderstorms.
The paper of M. B. P. Van Mons, reprinted
in Nicholson's Phil. Jour. Sept. 1809, induced
me to observe accurately the two different
kinds of lightning therein mentioned. I
will not venture to speculate on their causes,
referring for them to his paper, but shall pro-
ceed to state the difference, One kind is a
vivid flash, shortly afterwards followed by a
loud clap of thunder, resembling the sound
of the discharge of a mortar or cannon:
This is found to be the mischievous kind,
and is attributed to the discharge of the
fluid analogous to the flying off of the electric
spark. The other kind, ascribed by M. Van
Mons to the combustion of the gases of water,
is not so vivid, but has more latitude of light
and is followed by rolling thunder:* These
two sorts often alternate in the same storm.
But it is often the case in other storms that
* Two kinds of Hightning are mentioned by several
ancient writers. Consult Seneca, Nat. Quaes. lib. ii.
ec. 16. 20.
76 OF CLOUDS. CHAP. 2. § 12.
Y
none but the rolling thunder is distinguished.
The vespertine fulgurations, called summer
lightning, are not followed by any thunder
at all.
By a collation of journals, it appears that
the occurrence of thunderstorms is often.
nearly simultaneous in very distant parts of
the country, which indicates a disposition to
their formation taking place in large tracts
of atmosphere at once. But at other times
they are very local and detached. For more
particulars relative to the electric phaenomena
of thunderstorms and nimbi in general,
refer to the chapter on Electricity.
SECTION XII,
Of Masses of Cloud not to be referred to any of
the Modifications. or
MASSEs of cloud frequently appear, not re-
ferable for a time to any of the modifications:
but even these, if they last long enough,
generally break out into some modifica-
tion ultimately: when they do not, they must
be described in journals as well as they can ;
CHAP.2. § 12. OF CLOUDS. 77
but I have seldom seen any, which, if
watched long enough, did not show suffi-
ciently the character of some one of the mo-
difications, to be registered under its name.
As I have before observed, it is not always
an easy matter to an unexperienced meteo-
rologist to determine to which modification
every cloud he sees is to be referred. There
are intermediate varieties of cirrus, cirro-
stratus, and cirrocumulus, which approach
so much to the nature of each other that the
assignation of a name becomes very difficult.
A tendency to the orbicular arrangement
is the distinguishing character of cirrocu-
mulus; but sometimes features appear which
have somewhat of this kind of arrangement.
but are yet so light in their texture as to
appear almost to be of the modification of
cirrostratus. In my journals, I have called
these the cirrocumulative features of cirro-
stratus. There are many varieties of these
indeterminable features: a flimsy cloud of
this kind is often seen in the clearer intervals
of rainy weather, which gives the idea of the
flowers of the cauliflower. The innume-
rable little round spots of cloud which
sometimes cover a great extent of sky at an
7s. OF CLOUDS. CHAP. 2. § 12.
elevated station are sometimes of this flimsy
and almost transparent structure, while at
other times they are denser, and therefore
more decidedly cirrocumuli. In some kinds
of weather, often with easterly wind and
during cold unwholesome air, a cloud is
seen covering great part of the sky, which
has the thin and transparent texture of cir-
rostratus; but the component nubeculae have
the large and rounded form of cirrocumulus;
it seems to differ from the latter cloud in
being shallow and flimsy, and from the
former in having a rounded circumscription.
Among the sportive and amusing features
which are exhibited under other circumstances
of atmospheric pcculiarities, we have some-
times long tapering columns, horizontal or
inclined, of a cloud composed sometimes
of little cirrocumulous nubeculae, and some-
times of those of a sort of cirrostratus like
little freckles; or like bundles of small streaks,
arranged in rows. Mostly these little bunches
of cloud are in a plane; but I have thought,
though it might be an optical deception,
that they have been sometimes in a roundish
column, giving a faint resemblance to the
tail of an armadillo.
3
CHAP.2. § 12, OF CLOUDS. #9
I once saw a column of this sort inclined,
curved, apparently pendant from a sort of
cirrus, and coloured purple and lake by the
setting sun one afternoon in keen March
weather.” The cloud which gives what is
called the makerelback sky is composed of
the long waving cirrostrative nubeculae, but
these sometimes acquire the apparent sub-
stance and solid look of cirrocumulus.
In the large and long beds of nubeculae,
which frequently float gently over in
summer, there is often cirrostratus and cirro-
cumulus in the same bed: these change
from one to another by degrees; and there
are intermediate and also confused or plain
features in the same flotilla of travelling
WaterS. --- J.
Thus we see that though there be
intermediate and mixed features, they have
a constant resernblance more or less to one
or other of them, and a tendency to assume
sooner or later some regular form; a cir-
cumstance which shows the distinct nature
of the modifications, and persuades us that
the names have not been imposed at hap-
* Described under the account of the cirrostratus.
Bö) OF CLOUDS. CHAP.2, 5 13.
hazard or on artificial or imaginary dis-
tinctions; but that they represent distinct
and obvious genera of clouds, of which more
attentive observation points out numerous
species or subdivisions, z
SECTION XIII.
Of the apparent Fragments of Nimbi called Scud.
We may observe after showers, when the
nimbus appears to have spent itself, and the
separate modifications reappear in their
different stations, that there are loose dark
flocky detachments of clouds flying along in
the wind, and generally rather low down:
these seem like broken fragments of the
nimbus; the sailors call them Scud; they often
fly along in a lower current of wind, at a
time when large mountainous cumulostrati
and cumuli appear more stationary somewhat
higher up, and when flimsy features of
cirrostratus, cirrocumulus, and cirrus are
visible in a region still more elevated.
When this scud is abundant we may be
sure the imbriferous quality of the atmo-
cii. 2 #4 of clotps: 81
sphere rémains, and we may expect a return
of the showers. These fragments differ in
general from the flocky and nascent cumuli
which feed nimbi from below during rain,
iii being of a darker and more himbiform,
consistency. I have been at the top of the
Mountain Cader Idris when they have passed
below me through the valleys. They then
appeared like a dark purplish mist. But
sometimes whitish fleecy cumuli of similar
form sail along, and at others more compact
cumuli; there being almost all conceivable
varieties. These detached clouds are called
sometimes by the common people Water-
waggons, from being observed to supply
showers or to indicate their fall.
SECTION XIV.
Of the Mitture of the Modifications.
In shôwery and variable weather, when
thère is much cloud in the sky, we observe
," - ? * . . . . . . . . . . . ~ :- *
6ften such a mixture of different modifica-
• Ho - y . . . ) {
tions as must puzzle us to commemorate.
rºr, . . . . . . . . . * * i e
Here and there the semiformed shapes of
G
$2 OF CLOUDS. CHAP. 2. § 14.
cirrostratus appear in the general mass: in
another place irregular cirrus or cirrocumulus;
flat sheets seem to drop down into little de-
tached clouds of freckled appearance like cir-
rocumuli; cumuli are seen under, and milklike
whiteness spread aloft in other places. In
time the dense continuity of cumulostratus
prevails, and the confusion of nimbus and the
fall of rain again take place. To be acquaint-
ed with all these different appearances and
the different look of different skies, the mete-
orologist must watch them himself con-
tinually and attentively.
I am desirous of knowing whether in the
equatorial and polar climates any great dif-
ference in the modifications prevails from
those which happen here; from what I can
collect from travellers and from drawings,
there are few differences. The clouds of
England and Wales are I am persuaded much
the same as those of other parts of Europe.
I must mention that during my stay in
Wales I did not see any deeided cirrocumu-
lus; but this must have been accident; that
cloud is found no doubt in all parts of Europe
and in all parts probably of the world.
Indeed I feel little doubt but that, with some
CHAP. 2. § 15. OF CLOUDS. 83
few variations, all our clouds prevail every-
where. Accurate journals of them kept in
different parts of the world and commu-
nicated in the periodical journals would be
very interesting. \,
}
SECTION XV.
Of Rain, Snow, and Hail.
I have little to say of these three modes
of the resolution of the nimbus, which has
not been already treated of by meteorolo-
gists,” nor of their compound, commonly
called sleet.
The peculiarities of rain seem principally
to consist in the size, and close or distant
arrangement of its streams. I have observed,
that the large and distant streams of some
summer showers have often a strong positive
electricity. Rain has been found sometimes
positively, and at others negatively, electri-
fied; and sometimes nonelectric. ,
* Vid. Seneca Nat. Quaest.—Aristot. Meteor.—
Des Cartes Treat. Meteor. et caet.
G 2 "
84 COLOURS OF CLOUDS. CHAP. 2. § 16.
The peculiarities of snow seem to consist,
for the most part, in the size and shape of
the flakes. Sometimes they are of a sort of
stelliform figure. Hailstones vary in size
and shape. Such large ones sometimes fall,
as break windows, and do other mischief.
Of this a memorable instance happened some
years ago at Bruxelles. I think I remember
to have found some round and transparent
hailstones which contained opaque concentric
globes in the inside. Hail and snow have
generally been found electrified.* { * -
SECTION XVI.
of the Colours exhibitedly clouds.
It is an unfortuñate circumstance, that
there are no words in common use for
colours, in any known language, which are .
sufficiently explanatory. This circumstance
* Consult the experiments of Cavallo, Comp. Treat.
Elect.—Bertholon. Elec. Met. &c. See Chapter on
Electricity of Clouds.
CHAP.2. § 16. COLOURS OF CLOUDS. 85
arises probably from the great variety of
shades and combinations of colours which
flowers and other natural and artificial pro-
ductions every where display.
Clouds, as is well known, refraet and re-
flect a great variety of beautiful tints, the
shades of which vary according to their re-
lative position with respect to the sun; but
the colour seems also to depend on the kind
of cloud, and the degree of its density. The
cirrostratus shows the most beautiful and
varied colours. Different shades of purple,
crimson, lake, and Scarlet, are the most
common. The haze, with a horizontal Sun,
refracts different colours at different times;
yellow, orange, more or less of a golden hue,
red, and lake, are the most common; some-
times I have seen the haze refract a brown-
ish colour. The colour varies upwards;
sometimes I have seen several colours in the
haze. Particulars of which may be found
in my journal in Philos. Magaz. The colour
of clouds should always be noted down in
meteorological journals, as also the particular
modification in which the colours appear.
I have noticed that cirri, cirrocumuli, etc.
at different times show different colours,
\
86 COLOURS OF CLOUDS. CHAP. 2. § 16.
though in nearly the same situation with
respect to the sun.”
I have often seen the nubeculae of cirro-
cumulus forming in beds here and there,
about the time of sunset; highly tinged with
crimson, or with vermillion; colours which
more often affect the cirrostratus and not
unfrequently the cirrus.
There is one curious circumstance worthy
of notice with respect to the refraction of
colour in clouds. We often notice the light
clouds, cirrostrati for example, which show
fine colours just above the set sun and near
to the horizon at a time when they either do
not appear at all over head, or do not there
refract any colours. If it were only from
one place that these clouds were seen near
the western horizon, we might suppose that
they were local, but as all over large tracts
of country the same appearances would be
seen probably at the same time, we must
-:
A systematic arrangement of colours might be
made as well as of scents, by reference to flowers, and
other standard substances. It would be well if we had a
nomenclature for colours, which expressed them by refe-
rence to the proportion of the primitive tints of which
they may be compounds.
CHAP. 2. § 16. COLOURS OF CLOUDS. 87
conclude that the modification of cloud is
existing every where about, but that a par-
ticular angle with respect to the sun is neces-
sary to its being visible, or appearing as a
coloured cloud. *
We observe that clouds of the same vari-
ety, having the same local or angular position
with respect to the sun, sometimes appear
richly coloured, and at other times scarcely
coloured at all; a circumstance which ren-
ders it questionable, whether the colour is
from the cloud itself, or whether the cloud
only reflects the light which is coloured in
passing through the haze of the atmosphere
in the evening? The former is however
probably the case; for different clouds in
nearly the same angular position with re-
spect to the sun show different colours at
the same time. But the colours refracted
by the haze are very various. Sometimes
the tints in the twilight haze come on so
suddenly and are so circumscribed as to
induce a belief that very sudden and partial
changes take place in the atmosphere at
eventide; which may perhaps be somehow
connected with the formation of dew. It
is doubtless the falling dew which refracts
the colours in general, which are varied by
as CoLogBS QF groups. Char. 2.516.
the position of the parts in which they are
º a > , " , . . . . . # * -> - i ; -, A $º
seen. There is frequently a deep golden
orange close to the horizºn, 3. grimson
, , , ~ ; ºr: - T. * ... :: * if: " ; : * 'tºº ºr
blush above it fading into purple and
the dark blue, about it on each side 3.
T - - § { {}{* .
whitish transparent appearance, or a lively
greenish blue; or perhaps the true light
prismatic blue; and all these yary as the
sun gets lower beneath the horizon T pese
and numerous other beautiful appearances ºf
diverging streaks, bars, and spots may often
be seen with a horizontal sun; we notice them
chiefly in an evening, because we seldom
rise soon enough in the morning; but they
may be observed to display nearly the same
degree of beauty, though with some variety.
of appearance, when they usher forth the
gay Aurora, rising from the bed of the sable
Tithonus, as when they throw their painted
canopy over the declining gar of Phoebus,
and mark the place where he has sunk
beneath the ocean, till they fade away by
degrees, and are lost in the uniform gloom
of Night.
Chap.2. 517. ELEVATION OF CLOUDS. 89
SECTION XVII.
Of the Elevation of Clouds.
The mean or average degree of elevation
of the different modifications is different.
Aggarding to Mr. Howard, the cirrus is the
highest; the cirrocumulus next; and the cir-
rostratus, cumulus, and stratus, successively
lower than each other. The cumulostratus,
which is a compound cloud, is of vast ver-
tical dimensions: when it forms on a cumu-
Jus. the top of it appears to rise higher, and
the base generally lower, than that of the
cumulus. The nimbus, which is the reso-
lution of clouds into rain, may be considered
as having its base on the earth, and its
summit at the end of the fibres of its cirrose
crown.
The modifications have different degrees
of elevation at different times; and some-
& S ºr tº lº &
times the order of them is inverted: many
instanges of which may be found by con-
ulting journals. I have seen the cirrus in
. . . ; t (
twº mºving along rapidly in the wind,
below, Giºrogumulus, and even cumulus, in
so ELEVATION OF CLOUDS. Chap. 2. $ 17.
a higher region. Towards evening on Sun-
day, April 12, 1812, I observed from Clapton
a small fibrous cirrus moving rapidly along
in the wind, lower than fleecy cirrocumulus
which appeared in a comparatively calm re-
gion above. There were, however, other
cirri more elevated in the sky at the same
time. The following spring, on Sunday, the
21st March, 1813, at Cambridge, about 11 a.m.,
I remarked a long cirrus moving rapidly
along in a north wind, not lengthways, but
abreast. At one end of it fibres pointed
backward to the north, while at the other
they pointed to the east. Higher up, light
cumuli passed over from the south; and
higher still were flimsy ill defined masses of
cirrocumulative cirrostratus in an air compa-
ratively calm, but they were found to be
passing over gently from north west. Many
other cases of inverted order might be
noticed. Sometimes cirrocumulus may be
seen under a spreading sheet of cirrus of a
milky appearance, which look like a bas
relief. I have once or twice noticed the
nubeculae of a bed of cirrocumuli lower
down to be smaller than those of one more
elevated. This was noticed among the
CHAP. 2. § 17. ELEVATION OF CLOUDS. 91
abundance of cirrocumulus, cirrus, and other
clouds, which appeared on 21st Oct. 1811:
the night succeeding was cloudy, with a gale
from south and distant lightning. The long
lines of cirrus extending across the sky
have been found to be very high, by geo-
metrical observation. By the same mode of
mensuration, I found that I was frequently
much deceived in my opinion as to the
height of clouds at first view of them.
Saussure writes of the very great height
of clouds, which from the description
must be a kind of cirrostratus in mottled
beds, and Dalton mentions, that the clouds
of the mackerelback sky, as he calls it,
have appeared almost as distant from the
top of high mountains, as from the ground.”
That clouds are sometimes very high, there
can be no doubt: and their height may be
easily taken with quadrants at different
stations. Aéronauts have generally ascended
much beyond the cumuli; but I question if
there are not clouds much higher up than
any balloons have ever ascended. Mr. Sad-
ler mentioned to me, that large cumuli seen
* Dalton's Meteorological Essays.
s2 ELEVATION OF CLOUDS. Char. 2, #17.
by him, when at a much greater elevation
in a balloon, appeared like small silvery
specks on the ground; his distance from
them being so great, that they appeared to
rest on the earth's surface; but I have found
no accurate accounts of aeronauts having
ascended so far as the lighter modifications
sometimes appear to be elevated. *
Those who have been on the tops of high
hills and mountains, have frequently spoken
of clouds having passed below them; but
being unacquainted with the peculiarities of
clouds, and having been inattentive in their
observations, their accounts have been of
little value for ascertaining the general height
of the modifications; when I was at the
top of Cader Idris, on Sunday evening,
August 14, last, the weather being cleared
up after a showery morning, I noticed that
the scud passed above and below the tops of
the mountains, but the bases of most of the
cumuli were above them ; a long bed of
cirrus with fine fibrous edges was much
higher, so that my ascent up the mountain
hardly seemed to bring me nearer to it; but
the most exalted clouds of all were the flimsy
cirrocumulative forms of cirrostratus, Indeed
4.
Čitar. 2.; 17. EtßVATION OF Cf.OUDS. 93
it may often be observed that these transient
features of cirrostrătuş, which appear in the
intérvals of storms, are elevated much abové
the tops of cumulostratus, or cumulus,
which may be seen lower down. Future
observations by means of trigonometrical
measurement may, when the differences of
clouds become more generally known, lead
to a more accurate estimate of the heigth
of the different varieties. In general, the
regular ephemeral cumuli have much the
same elevation, which somewhat increases
during the day from the rising of the vapour
plane whereon they float. I have made
observations with a view to determine
whether cumuli were not usually higher
over some soils than over others, but I
cannot perceive much difference in this re-
spect; they certainly have appeared some-
what lower when over the sea, than when
they have come over the land; I noticed
this at Hastings, in August and September
ôf the present year. Before rain they de-
scend lower, increase irregularly in size, and
are condensed into cumulostratus. I have
noticed that when cumuli, which were flying
along in the wind, have by any accidental
tº STRUCTURE OF CLOUDS. Char. 2.51s.
inosculation of the clouds, or from any other
cause, changed to cumulostratus: the change
has been uniformly attended with a retar-
dation of the motion of the cloud. This
probably arises from its having been increased
in density in proportion to the surface pre-
sented to the wind.
SECTION XVIII.
of the Structure of Clouds.
THE first step towards a perfect know-
ledge of any science, is to have an accurate
and well arranged detail of particular ap-
pearances. From effects thus laid out in
order, we proceed to examine what may
have been their causes. It may be proper
now to examine, whether the particles of
clouds remain afloat in the air, or only gra-
vitate very slowly to the ground In other
words, on what peculiarity of structure does
their comparative levity depend ? Experience
being deficient, conjecture supplies its place,
and supposes an adequate cause.
M. de Luc, and M. de Saussure, have
I
Char. 2, § 1s. STRUCTURE OF CLOUDS. 9s
supposed that they may be composed of hol-
low vesicles;* and, in this case, if the com- .
ponent vesicles should contain an aériform
fluid, lighter than common air, they would
become buoyant, and float in the atmo-
sphere. It is not probable that they contain
hydrogen gas. For, if they do, what can
be the structure and component parts of the
vesicular bag itself? It cannot be water.
For, if electricity should preserve it in the
vesicular form, it could not prevent the
escape of its hydrogen from within. Could
the bag itself be water, it would never be
oxygen and hydrogen in a state of combi-
nation. The oxygen would not affect or
act upon the hydrogen in the bag, because
it had already combined with its due pro-
portion of hydrogen, and become water.
Nothing, then, but an accession of more
oxygen could convert the contents of these
vesicles into water. When the electricity
is equalized, the water which composes the
bag or vesicle comes down in rain; and the
hydrogen, mixing with common air, may be
exploded by the electric spark, or, meeting
* Idées sur la Meteorologie, par I. A. de Luc, vol. ii.
p. 160.
96 STRUCTURE OF CLOUDS. CHAE.g. $18.
with oxygen, may explode spontaneously,
and produce one kind of lightning and thun-
der. This is, however, only vague conjec-
ture: nothing is certainly known about the
structure of clouds. It would make a very
pretty theory, with the solution of the fol-
Iowing questions. 1st. What are the cir-
cumstances under which hydrogen could be
contained in a vesicle of water; And, 2dly.
What can occasion such a separation of the
gasses on a condensation of vapour into
cloud: In short the opinions contained about
vesicular vapour seem in general to have
been vague and illfounded. That the struc-
ture of different clouds is very different, is
manifest from their different refracting and
reflecting powers, producing the various ap-
pearances of the halo, corona, parhélion, etc.
on different occasions, as well as from the
very different appearance of the clouds them-
selves. e
But there is, in fact, no proof that the
particles of water have any specific levity in
the air; they may, perhaps, only gravitäté
very slowly to the earth, from their mińuté-
ness, as soon as from any cause the elastic
vapour is condensed into a visible cloud.
The manner in which such aggregates may
•, CHAP. 2. § 19. OF THE HALO, CORONA, etc. 97
constitute a visible and floating cloud, which
preserves or increases its elevation, has been
explained by Mr. Howard in his account of
the vapour plane, and the cause of the
cumulus.*
SECTION XIX.
Of certain Luminous Appearances which result
from the Reflection or Refraction of Light by
Clouds, and which are commonly called Halos,
Rainbows, Parhelia, etc.
Every one who is conversant in meteoro-
logy must be well acquainted with such lu-
minous appearances, occasionally seen about
the sun, moon, and planets, and caused by
the refraction of their light through a cloud
of peculiar structure, as are usually called
halos, coronae, burrs, glories, &c. But these
phaenomena have hitherto received no defi-
nite names whereby they may be distin-
guished from each other, though they differ
considerably in appearance. Meteorologists
have spoken of halos and crowns of light indis-
* Howard on Clouds, in Phil. Mag.
H
ps OF THE HALO, CORONA, Char. 2.; 19.
criminately, without distinguishing between
the corona or luminous disk, and the halo or
luminous ring. *
The ancient writers, too, spoke indiffer-
ently of halones, circuli, coronae, halyses,
parhelia, and other the like phaenomena, as
appears by the works of Aristotle,” Pliny, f
Seneca, and others. Aristotle appears to
have written with the most perspicuity of
all of them. -
With a view to obviate the inconvenience
and misunderstanding which might arise
from the confusion or promiscuous use of
terms not sufficiently definite, I subjoin the
following classification, which, though im-
perfect, may serve, till a better shall be
found, to enable meteorologists, in their
journals, to express, with tolerable preci-
sion, the kind of appearance which they
wish to commemorate.
I endeavour to classify them (for want of
a better criterion) according to the various
shapes or figures which they present. It
* Aristot. Meteor. lib. iii. cc. 2, 3.
+ Plin. Hist. Nat, lib. ii. cc. 29, 30, 31, 32. lib.
xviii. 35. -
# Senec. Nat. Quaest, lib. i. cc, 2, 3, 4, 5, 6, 7,
Chap. 2, § 19. RAINBOW, PARHELION, etc. 99
must be remembered, that their various
figures are the result of the particular con-
struction of the cloud which refracts their
light: a correct attention, therefore, to these
appearances, may lead to a more perfect
knowledge of the structure of the refracting
medium.
HALo.” Pl. VI. Fig. 1. Circulus vel Annu-
lus lucidus aream includens, in cujus
centro Sol aut Luna apparet.
By a halo I understand an extensive lumi-
nous ring, including a circular area, in the
centre of which the sun or moon appears;
whose light, passing through the intervening
cloud, gives rise to the phenomenon. Ha-
lones are called Lunar or Solar, according
as they appear round the moon or sun.
Those about the moon are the most com—
mon. They are generally pretty correct
circles: I once, however, saw a halo of a
somewhat oval figure. Halones are some-
* The word halo, or halos, is evidently derived from
the Greek &w or 3A05, signifying an area. The Latin
writers appear to have spoken indifferently of halones,
halyses, coronae, circuli, &c. without sufficiently distin-
guishing between the corona and the halo.
H 2
100 OF THE HALO, CORONA, CHAP. 2. § 19.
times coloured with the tints of the rain-
bow.”
HALo DVPLEX. Pl. VI. Fig. 2. Duo An-
muli, in quorum centro communi Sol aut
Luna videatur. *
A double halo is not a very common
occurrence. I have observed, that simple
halones are generally about 45° in diameter:
in case of double halo, it might be worth
while to take the diameters of each of the
concentric circles. * --
HALO TRIPLEX. Tres Annuli, in quorum
centro communi Sol aut Luna appareaf.
Triple halones are extremely rare occur-
Fen CeS.
HALo Discoides. Pl, WI. Fig. 3. Annulus
aream reliquá nubis parte lucidiorem
continens, in cujus centro Luna aut
Sol visus est. bº
A discoid halo may be said to be a
halo constituting the boundary of a large
corona: it is generally of less diameter than
usual, and often coloured with the tints of
* The coloured halo is generally seen in a denser kind
of cirrostratus.
CHAP. 2. § 19. RAINBOW, PARHELION, etc. 101
the Iris. A beautiful one appeared on the
22d of December, 1809, about midnight,
during the passage of a cirrostratus before
the moon.
CoRoNA. Pl. VI. Fig. 4. Discus lucidus,
vel portio circularis nubis reliqud luci-
dior, in cujus centro Sol aut Luna
widetur.
When the sun or moon is seen through a
thin cloud, a portion of the cloud, more
immediately round the sun or moon, appears
much lighter than the rest of it: this lumi-
nous disk, if I may be allowed the expres-
sion, I call a corona.
Coronae are of various sizes, according to
the peculiarities of the intervening vapour:
but they seldom exceed 10° in diameter:
they are generally faintly coloured at their
edges.
Frequently, when there is a halo encir-
cling the moon, there is a small corona more
immediately round it. Coronae, as well as
halones, have been always observed to prog-
nosticate rain, hail, or snow. As far as I
can observe, they are generally seen in the
cirrostratus cloud.
CoRoNA DVPLEX. Discus lucidus, alium
I02 OF THE HALO, CORONA, CHAP. 2. § 19.
discum paulo lucidiorem ac minorem in-
cludens, in quorum centro communi Sol
vel Luna videfur.
A double corona is very common : some-
times they are triple or quadruple.
PARHELION. Pl. VI. Fig. 5. Imago Solis
falsa, vel plures imagines ejusdem ge-
meris circa Solem circulatim dispositae,
et magis minisve halonibus aliisque luci-
dis vittis commitatae.
Parhelia vary considerably in general
appearance: sometimes the sun is encir-
cled by a large halo, in the circumference
of which the mock Suns usually appear:
these have often small halones round them :
they have usually a horizontal band of
white light of a pyramidal figure extend-
ing from them : sometimes a large semi-
circular band of light, like an inverted arch,
seems to rest upon the halo which encircles
the sun : but these phaenomena vary too
much to be particularly described here:
their peculiarities ought to be minutely ob-
served and noted down in a Meteorological
Journal.
PARASELENE. Lunae imago falsa, vel
plures imagines hujus generis, circa
CHAP. 2. § 19. RAINBOW, PARHELION, etc. 103
Lunam dispositae, et magis minisve
halonibus aliisque lucidis wittis commi-
tatae. *
The paraselene, the parhelion, and the
several kinds of halo and corona, all appear
to result from the intervention of cloud
between the spectator and the sun or moon,
through which the light passes: but there
is another well known phaenomenon, which
always appears in a cloud opposite to the
Sun or moon; namely, the
IRIs. Circulus marimus coloratus in
nube Soli opposità visus, et cujus
centrum centro Solis opponitur, qui,
quod portio ejus tantùm videtur, arcus
adparet.
The rainbow is an appearance too familiar
to every one to need any particular descrip-
tion. As the halo and corona appear gene-
rally in the cirrostratus cloud; so the Iris
appears always in the nimbus. Lunar rain-
bows are rare OCCurrenCeS.
IRIs ovelEx. Duo Circuli colororati,
quorum centrum commune Solis centro
opponitur, qui quðd eorum portiones
tantum videantur Arcus adpareant.
Double rainbows are not unfrequent. The
104 OF THE HALO, CORONA, etc. CHAP, 2, § 19.
order of colours in the outer one is reversed.”
They are mentioned by Aratus.t
IRIS wVIcolor. Circulus maximus colorum
eacors, in nube visus, et cujus centrum
centro Solis vel Lunae opponitur ; qui
quod portio ejus tantum videatur Arcus
adpareat.
The Iris unicolor is more properly a co-
lourless rainbow, and appears in the mist,
Such a one appeared on 20th November,
1812, in the vicinity of London. The after-
noon of the same day there was a shower
in which the rainbow showed the usual
colours. ^
RABDI DIVERGENTEs. Radii Solis radiantes
ob quandam specialis generis interpo-
sitam nubem.
The remarkable appearance of the sun's
rays, in a cloud before rain, has been
alluded to by Aristotle, § Virgil, || and
others.
RABDvs PYRAMIDALIS. Portio pyramidalis
lucis in nube visa, quasi ea. Sole proce-
* Arist. Meteor. lib. iii. cap. 5, + Arat. Dios. 208.
f Annals of Philosoph, by Dr. Thomson, p. 80.
§ Arist. Meteor. lib. iii. cap. 2.
| Virgil Georg. lib. i., v. 445.
CHAP.2. §20. CAUSE OF THE HALO, etc. 105
dens, cujus vertea diametro Solis hori-
zontali perpendicularis est.
Not uncommon in haze of a peculiar kind,
perhaps cirrostratus. Sometimes small por-
tions of the rainbow's colours appear in dif-
ferent places. I observed this between seven
and eight o'clock, 21st August, 1812, while
riding between Ticehurst and Wadhurst, in
the neighbourhood of Tunbridge Wells.
SECTION XX.
Of the Causes of the abovedescribed Phaenomena.
IN examining what may be the causes of
the various phaenomena above described,
I make a division of them into—1st, those
which result from the intervention of cloud
between the spectator and the luminous
body. And, 2dly, those which appear in a
cloud opposite to the rays of the sun or moon.
Of the 1st sort are all the different kinds of
halo, corona, and parhelion. Of the 2d sort
are the different varieties of the Iris. With
regard to the first kind of these, caused by
intervention of clouds, many attempts have
106 CAUSE OF THE HALO, &c. CHAP. 2. $20.
been made by different philosophers to ex-
plain them; but they have been generally
founded more on vague conjecture than fact.
All that can be said about them is, that they
probably depend upon some peculiarity in
the refractive or reflective powers of the
intervening cloud, by which certain of the
rays are thrown off at a particular angle.
I may, in the first place, observe, that all
the rays from the sun or moon must fall
nearly parallel on the surface of the cloud.
This will be evident, if we consider the
great distance of those bodies, when com—
pared with the diameter of the largest halo.
The rays which constitute the luminous
ring of the halo, must be reflected at an
angle equal to the angle of the semidiameter
of its area; or, in other words, to the angle
subtended by the distance from the sun or
moon's centre to the ring. To illustrate this,
I subjoin the following problem and figure.
CHAP. 2, § 20. CAUSE OF THE HALO, etc. 107
3/ -
º *
e ºf
A M B
• * * * * e e s e o 'o e tº tº @ Q @ e º O tº e
$
º sº 4.
•
tº * > & e
wº * > © *
º * sº
o © O Aº
* tº sº
ſº dº
o Çe
$º & a
* >
e tº *
Ǻ tº sº wº
cº Ye
fº © * >
º ( ) sº
* > * sº
* 4- gº
* > º *
&
* > ©
tº * tº
« » & : c
* te sº
HD gº tº e º 'º Q & Q º O © tº E e & e i e º O & © & Cº. º & C
The distance of the sun or moon from
the cloud bears so great a proportion to the
diameter of the halo, that the rays may be
said to fall physically parallel on all parts
of it; that is, if of two rays coming from
the sun's centre, one should impinge on A,
and the other on B, these rays might be
considered as parallel. Let A B be the dia-
meter of the halo, M the centre or place
where the moon appears: if a ray, a y, pro-
ceeding from the moon in the direction a y,
and impinging on A, should pass through
the cloud in a straight line, that is, perpen-
dicular to A B, it would appear to a spec-
108 CAUSE OF THE HALO, etc. CHAP.2, $20.
tator at D. But it appears to a spectator
at E.; therefore it diverges from the straight
line A D in the line A E, making with it
an angle D A E ; join MA and M E, and E
D, making A D E M a parallelogram, and
A E its diagonal. Then (Euc. i. 29.) the
angle D A E, or angle of the aberration of
the ray, is equal to the alternate angle A E
M, or angle under which the semi-diameter
A M of the halo A B appears.
From the above, it appears then, that
a halo of 48° diameter may be ascribed to a
property in the cloud of refracting certain
of the rays at an angle of 24°. A double
halo, the exterior ring whereof includes an
area of 48°, and the interior ring whereof
includes one of 10°, must be attributed to a
property in the cloud of refracting certain
of the rays at an angle of 24”, and certain
other rays at an angle of 5", and so on of
triple ones.
A corona of 10° diameter appears to be
the consequence of a property in the cloud
to refract certain of the rays at every angle,
from the smallest, say an angle of 1" to 5°,
beyond which the rays are refracted in the
cloud, in the usual manner. A double corona
the inner one of which is 5° diameter, and
CHAP.2, $20. CAUSE OE THE HALO, etc. 109
the outer 10°, is referrible to a property in
the cloud of refracting certain of the rays
at every angle, from 1" to 2° 30', and
certain other rays, from 2° 30' to 5°, and
so on of triple ones.”
For further particulars relative to these
phaenomena, I refer the reader to the works
of Aristotle, Newton, Huygens, Des
Cartes,S M. Helvetius," and to several
papers in the Philosophical Transactions.”
and Manchester's Memoirs.fi For expla-
nation of the phaenomena of the rainbow,
consult Newton's Opticks.
By the problem above it appears, that no
two persons standing at any distance from
each other, and looking at a halo, see the
* Even the breadth of the ring of a halo itself must
be caused by a number of rays, refracted at somewhat
different angles; otherwise the breadth of the ring would
equal only the breadth of one ray.
+ Aristot. Meteor. lib. iii. cc. 3, 4, 5, 6.
f Newton, Optic. 1st edit. 2d book, pp. 48, 134.
|| Huygens's Post. Works, pp. 293.
§ Des Cartes. Treatise of Meteors.
*| M. Helvetius. End of Mercurius in Sole.
** Phil. Trans. vol. v. 1065. xxii. 535. xxxi. 212.
xxxix. 218. xlvi. 196. lii. 3.
++ Manchest. Mem. vol. iii,
110 of EvaPORATION. CHAP, 2,321.
same light: but as the halo is seen for a
great extent around by persons in different
places, al disposition to such reflexion or
refraction of the rays is inferred as existing
in large and extensive masses of the same
cloud. It may be a fit subject of inquiry-
At what distances is halo seen at the same
time Sometimes the cloud seems very par-
tial, but at others very extensive. When a
halo appears in a cloud, the extremities of
which can be seen, it may serve to mark
that cloud as a subject of geometrical obser-
vation at several distant stations, whereby
its distance and magnitude may be nearly
ascertained. . . . .
In some parts of America halos are said
to be still more common than in England.
SECTION XXI.
Evaporation. -
According to the most recent theory,
the following will be the process of evapo-
ration. The accession of diurnal tempera-
ture communicating to the water the power
of calorific repulsion, the production of
Chap. 2. $21. OF EVAPORATION. 11 I
elastic vapour, or gas, is the consequence;
which, exerting its elastic force by the
repulsive power of its particles, rises into
the atmosphere; but when a fluid becomes
an elastic body, there is a loss of heat of
temperature by expansion : and the vapour,
therefore, becomes cooler than the water
from which it evaporated, and also cools as
it expands on its progress, causing the upper
air to be cooler into which it ascends; for
it has changed its heat of temperature for
heat of capacity;” so that the actual tem-
perature of the air is diminished upwards:
while the said gas, possessing heat of capa-
city, is thus enabled to remain an expanded
elastic fluid ; and it is only by an actual loss
of heat, from the nocturnal interception of
the sun's rays, that the whole mass of
atmosphere, being cooler, is then again con-
densed into aqueous particles, and falls in
dew; by which process the heat of capacity
is again changed for the heat of temperature;
and the reformation of water in the form
of mist or cloud, actually increases the
* I adopt the mode of expression of Sir H. Davy.
See him in his Elem. of Chem. Phi.. vol. i. part i. v. 1,
2, 3, &c.
3.
112 OF EVAPORATION. Chap. 2. $21,
thermometric warmth, in falling; and thus
contributes to equalize the vespertine with
the diurnal temperature, and to make the
change more gradual. The formation of
clouds may be regarded as dependent on
circumstances which attend this process;
for the rising of the elastic vapour impels
that above into an atmosphere already too
cold for its solution, which, therefore be-
comes cloud, as explained before.
As the particles of a cloud, for example
a cumulus, are not believed to be kept sepa-
rate by the same power of repulsion as those
of elastic vapour, and as clouds are electri-
fied, so we ascribe the mutual repulsion of
their corporeal particles to that of similarly
electrified bodies: now, according to New-
ton, where repulsion ends, there attraction
begins; and if by the joint influence of
these two powers, the cumulus is kept toge-
ther as an aggregate, while its particles do
not unite, so as to form water, we must
suppose that the same principle holds good
with respect to electrical attraction and re-
pulsion. After all, these are merely theo-
ries, against which there appear as many
reasons as there are for them. The inqui-
2
CHAP. 2. § 21. OF EVAPORATION. ' 113
sitive mind of man is always seeking for
causes, and making systems, by which even
the most incredulous are liable to be misled,
and to mistake imagination for truth; while
the only resource of the philosopher is to
arm himself with their mutual contra-
dictions and common want of evidence,
and, retracing the steps of his wandering,
to sneak back into the plain regions of sim-
ple observation, and content himself to be-
hold the variety and order of phaenomena.”
* Dew is vapour condensed into visible drops. Under
whatever circumstances of diminished barometrical pres-
sure or decreased heat the air cannot hold so much water
in solution as before, the result must be a deposition of it
in aqueous particles; during day and under some other
circumstances of electricity, definite and floating clouds .
are the result, and the processes of rain often commence;
but in fine weather, in the evening, the vapour plane
being destroyed and the nubific principle ceasing to act,
the vapour so deposited comes down in dew. The dew is
not the result always of the stratus, and it differs from the
wet mist of the cirrostrativeness of the lower atmosphere.
The circumstances under which dew is most plentifully
formed being treated of by Dr. Wells in his Essay on
Dew, Irefer the reader to that publication, and also to
Bertholon's Elect. Met. !
*~
114 OF METEORS. Char.g.
CHAPTER III.
OF CERTAIN ACCENSIONS WHICH APPEAR TO
TAKE PLACE SPONTANEOUSLY IN THE ATMO-
SPHERE, CALLED FALLING STARS, METEORS,
ETC.
THE igneous meteors which occasionally
take place in the atmosphere, have been
noticed by most of the ancient writers on
natural philosophy with which we are ac-
quainted, as may be found, by the works
of Aristotle.” Pliny, Virgil, Lucretius,
Seneca,S and others. But the peculiarities
remarkable in the different kinds of them
do not appear to have been duly noticed.
The most minute differences between them
ought to be commemorated, together with
their relation to other coexisting phaeno-
mena: for in investigating the causes of
* Arist. Meteor. lib. i. c. 4.
† Plin. H. N. lib. ii. cc. 4, 25, 36.
f Virg. Georg. lib. i., 365.
| Lucret. de Rer. Nat, lib. ii. 206. lib. v. 1190.
§ Senec. Nat. Quaest. lib. i. c. 14.
CHAP. 8. OF METEOR3. il 8
these luminous accensions, we shall probably
be assisted by observing and noting down
accurately peculiarities remarkable in the
different kinds of meteors which from time
to time appear. The very large sort, which
occasionally are seen; such, for example,
as that memorable meteor which happened
on the 18th of August, 1783, that which
took place in November, 1803, or the large
one recently observed at Geneva,” are not
numerous enough to admit of being arranged
under any general description; besides which,
there are peculiarities in all of the larger
sort, whereby each differs from every other.
But the smaller kind, which appear in
common, seem to me to be referrible to
three principal varieties, which appear to
derive their particular character from the
kind of weather in which they happen.
* See Nicholson's Journal 1811.
The falling stars have generally been regarded as fore-
boders of wind: so Seneca in Hippolyto:
* Ocyor cursum rapiente flamma
Stella curh ventis agitata longós
Porrigit ighes,
I have flotieed this indication of wind particularly
from the caudate ifièteers still to be deseribed,
I 2
116 OF METEORS. Char.s.
The most common sort are those very
small meteors which are prevalent in clear
frosty winter nights, and in summer also,
when there are dry easterly winds with a
clear sky. They have very much of the
appearance of the real stars, and have pro-
bably, from this circumstance, derived their
vulgar name: they leave little or no train
behind them, and shoot along in straight
lines, generally obliquely downward, but
sometimes horizontally.” ---
The second kind are larger and more bril-
liant, and generally appear in warm summer
evenings, particularly when cirrocumulus,
cirrostratus, and thunder clouds abound:
some of them are very beautiful, and give
much light: they vary somewhat in colour
and size. They have sometimes a curvilinear
motion.
The third sort are strikingly different
from the two above mentioned: they are
generally small, and of a beautiful bluish-
white colour; but their peculiar characte-
* I think I have observed that in summer time, when
any kind of falling stars appear, some feature of cirro-
stratus, however small, may generally be seen about.
But this does not appear to be always the case in winter.
1
CHAP. 3. OF METEORS. 117
*
ristic is that of leaving long white trains
behind them, which remain visible for some
seconds in the tract in which the meteors
have gone. These tails which I have endea-
voured to represent in Plate VI. Fig. 6.
seem to be lost by dispersion; they appear
to fly off from all points, increasing in
breadth as they become fainter, till at last
they cease to be distinguishable. They are
generally seen in the intervals of showery
weather, and are most prevalent before the
occurrence of high wind: of which they
have been considered by Aratus, Virgil, and
other writers as a certain prognostic.”
* Kai 3.3. wa. usXavoy &r’ &eps; diagogi
Toppéx Tot 3° 3710sy pugol Wroxevkawaytal
Agiºſal zeivot; ovrºv obov špxop.svolo
IIysvgoro;, &c, Arat. Dios. 107.
Saepe etiam stellas vento impendente videbis
Praecipites coelo labi, noctisque per umbram
Flammarum longos a tergo albescere tractus.
Georgic. lib. i. 365.
Pliny also remarks, “Si volitare plures stellae wide-
buntur quo feruntur albescentes, ventos ex his partibus
nunciabunt.” Plin. Hist. Nat. xviii. 35.
Compare also Lucretius de Rer. Nat. ii. 208. Theo-
phrastus observed of old: “O0sy %y areps; barrogi Toxxon
awsgow Eyrvºs, say 3: Tayloxoffey opolwg, Toxx, Tysvgolx onwarvovoi.
w Theoph. de Sign. Went.
118 OF METEORS. CHAP. 3.
These kind of meteors abounded, on the night
of 10th August, 1811, after a showery day,
I have thought that their tails were the re-
suit rather of some gas set on fire by the
meteor in its passage, than of any of the
luminous substance of the meteor left be-
hind it, I may also remark, that if the
larger kind of meteors happen at the same
time that these caudate meteors are preva-
lent, they also leave this beautiful white
and slowly evanescent tail behind them.*
* The train of light which the common meteors, or
falling stars, appear to leave behind, and which lasts
scarcely a moment, seems frequently to be an hallucination
of vision, like the ACXinooxtow eyxog sung by Homer, and
quoted by Dr. Darwin, Zoom. sect. iii. v. 3.−to which,
as well as to his paper, De Oculorum Spectris, I refer the
reader. Mr. Aubert observed a train of reddish fire
left behind the bright meteor seen at London, Oct. 4,
1783, which lasted above a minute after the meteor was
extinguished. See Phil. Trans, vol. lxxiv. 115,
The great meteor of 18th Aug. 1783, left corruscations
behind it, and moved in an irregular tract. See Phil.
Trans. lxxiv. 114,
There are some reasons for thinking that the explo-
sion and loud report of some meteors, and particularly
of the great one of 1783, happen at the alteration of
their regular course, as if interruption by explosion of
hydrogen, which the meteor might meet with in its pas-
£HAR, 3. $1. QF METEORS, 1.1%
SECTION I.
Of the Causes of the Igneous Meteor, described
above.
WARHous have been the conjectures of
different philosophers about the causes of
igneous meteors: their precise cause has,
however, never been ascertained. M. De
Luc ascribes them to certain phospho-
rific exhalations, which ascend from the
earth, and take fire or become phospha-
sage, or from any other cause, caused the report, and
division of the luminous substance of the meteor.”
There is one remarkable thing about the explosion
of meteors. The great meteor of 1718 was, according
to Halley, above sixty miles from the earth's surface;
and yet at that elevated station the air was capable of
communicating sound, as appears clear by the report
of the meteor: a circumstance noticed by Arbuthnot,
and by the Abbé Bertholon in his “De L'electricité des
Meteors. 8vo. Lyons, 1787, vol. ii. p. 25. Where are
some curious observations on the Feux St. Elme, Feux
Follets, and other meteors.
* Phil. Trans, lxxiv. 20.
190 OF METEORS. CHAP. 8. § 1.” -
rescent in the air.” We shall see how this
hypothesis will agree with their kind of
motion, their peculiarities, and the kind of
weather which precedes, accompanies, or
follows them. *
On the above supposition, we must re-
gard them as taking place in the following
manner. The exhalation from the earth
must be a circumscribed column of some
kind of wolatile matter, which, when it
arrives at a certain elevation, takes fire:
this might easily be supposed to happen to
phosphorific matter. There are several other
appearances which incline one to think, that
there are combustible gaseous exhalations
from the earth, which afterwards ignite.
The next question is, if they are only phos-
phorific, as M. de Luc calls them, what is
the principle of their ignition They may,
perhaps, be ignited, by getting up into a
dryer atmosphere. This supposition is
agreeable to the known properties of phos-
phorus, which is preserved in water, but
burns if left to dry. It may perhaps be
* Nicholson's Journal of Nat. Phil, etc. 1812.
CHAP. 8. § 1. OF METEORS, 121
conceived that phosphorous gasses may be
preserved while passing through a humid
atmosphere ; but which, when they arrive
at a more dry air, spontaneously take fire.
The ignition being thus began, it would pro-
bably extend down the column of phospho-
rific vapour, and give the appearance of a
descending luminous ball, just such as we
see to be the case: and it might go out
when it had descended again so low as to
be in an air too humid for combustion. Or
its extinction may, in other cases, be caused
by the column of vapour being interrupted
by wind, or any other cause of dispersion.
Upon the above supposition, the motion
of the falling star would be exactly retro-
grade to that of the ascending column of
posphorific matter. This is agreeable to the
popular notion, that many of these meteors
shoot towards the quarter from which wind
will subsequently blow. Because if, as I
have shown, the wind often changes first
above, its current may give an inclination
to the ascending column of phosphorific
matter; and the burning star, moving back
in an opposite direction, would point to the
coming wind. This may often be the case;
122 OF METEORS, CHAP.3.3.1,
but I have observed that these stars fre-
quently shoot along in different directions:
a circumstance which may be supposed to
arise from their previous columns of phos-
phorific matter being inclined differently by
different currents, which, by experiments
with air balloons, I have found to exist
often in the atmosphere at the same time,
If these columns of phosphorific matter
ascend from the earth when there are dif. ,
ferent currents of air in the atmosphere, it
may be questioned, how it happens that the
motion of the falling meteor is so straight,
and why, on the contrary, it is not bent at
angles, as its motion is retrograde to that of
an ascending column of gas, which may
have passed through, and received an incli-
nation from, several currents of air? Possi-
bly, it may be replied, between the currents
there may be a deposition of water, or some
other circumstance, which may extinguish
burning phosphorus; and then an alteration
of the current may be one circumstance that
sets a boundary to its combustion, which in
other cases may be continued lower. I can
conceive that the change of current might
interrupt the continuity of the ascending
3
CHAP. 3. § 1. OF METEORS. 123
column; and thus the star might go out
when it arrived at the interception of the
combustible gas. But it is hard to assign a
reason why these columns of gas, if such
exist, should not be dispersed entirely by
the wind which they must meet with in the
progress of their ascent; since they some-
times are seen when the wind is blowing
very strongly below. This alone would
induce one to believe, that they do not
really ascend from the earth; but still they
may be formed in the air, perhaps at the
junction of two currents. It is moreover
difficult to conceive why exhalations from
the earth should arise in such narrow co-
lumns, as they must do, if this explanation
of the phaenomena be true.”
If the meteors in question be caused by
* A meteor, moving in a very unusual manner, was
seen at Hackney, on the night of the 7th of November,
1811, about five minutes bêfore nine o'clock, in the
North: it moved in a direction to the West: its motion
was not regular in a straight line, nor in a uniform
curve; but it leaped forward by suecessive jerks, describ-
ing a sort of undulated track; and it was of considerable
magnitude: after being visible for some seconds, it appa-
rently entered a cloud, and disappeared. The circum-
stance of its peculiar motionis, I think, worthy of record,
124; OF METEORS. CHAP. 8. § 1.
the ignition of combustible exhalations, it
may be easily supposed that they would
vary in appearance, according to the pecu-
liarities of the exhaled gas. Neither is it
more difficult to suppose varieties in these
exhalations, than to suppose their existence
at all. The columns of gas might vary in
size at different times, and so give place to
meteors of divers magnitudes. The greater
the quantity of the exhaled gas, the less
likely would it be to be wholly dispersed
by the wind: it might, therefore, be carried
along horizontally for miles; and, at length
taking fire by dryness of the air, by electri-
city, or by other causes, might give place to
such large, irregular, and horizontally moving
meteors, which appear at uncertain intervals,
and travel over vast tracts of country. But
this seems to be rather an ingenious hypo-
thesis of M. De Luc, than a theory founded
on facts.
There are two circumstances about me-
teors, which seem to favour an opinion which
I once entertained, that they are somehow
connected with the combustion of hydrogen.
They sometimes end with a loud report.
And one kind of them is most frequent after
CHAP. 3. § 1. OF METEORS. 125
* rain, and in stormy weather. The separa-
tion of the gasses of water has been men-
tioned by M. B. P. Van Mons, in a paper
given to the Batavian Society. If hydrogen
be thus separated, and partly mixed, as it
must be, with common air, and should be
ignited, we may conceive a meteor pro-
duced: but this is not sufficient to account
for their long course which is generally in a
slanting downward direction. The occa-
sional report of the meteor at its termina-
tion may be supposed, however, to be
caused by its meeting with hydrogen gas in
its descent, and setting it on fire. This
explosion, too, may interrupt the column of
combustible gas, and thus put an end to the
meteOr.
In attributing igneous meteors to the com-
bustion of gasses, which ascend from earth,
we assume what cannot be proved : for no
one has, I believe, seen such columns of
combustible gas.” There are, however, some
circumstances which would induce a belief
* The opinion of Aristotle about the cause of meteors
seems to agree in some measure with that of M. De Luc.
Consult Arist. Meteor, lib. i. cc. 2–4.
126 of METEORs cast 8.31.
of their existence.* The well known me-
teor, called Ignis Fatuus, which appears over
marshy grounds, and the electric light seen
about plants hereafter to be described, which
one would naturally attribute to the com-
bustion of terrestrial exhalation, lead us to
ascribe more elevated accensions to a similar
Call SC,
* On Sunday evening, Aug. 11, 1805, I observed a
very unusual exhalation from an elm tree at Clapton, in
the parish of Hackney; the particulars of which are as
follow. Between 6 and 7 p.m. the sky being clear, and
the weather warm and dry, and wind, South East, a
column of darkish vapour appeared to arise from the top
of an elm tree at some distance: it looked about two or
three feet high : after it had continued a few seconds, it
disappeared; and, after a few seconds more, reappeared;
and continued in this manner, on and off, for nearly half
an hour, when it became too dark to distinguish it any
longer. More particulars may be found in the Günt.
Mag. for 1805, p. 816.
Char, 8. § 2. OF AEROLITES. 127
SECTION II.
Of Aérolites.
THE large masses of substance which oc-
casionally fall from the air vulgarly called
Lunar Stones, Meteoric Stones, Aérolites, etc.
of which accurate analyses have now been
published, seem to be made up of ingre-
dients composed in proportions different
from those of any known terestrial com-
pound; and are probably formed in our
atmosphere; at least such is my opinion, the
result of an examination of all the evidence
I have been able to collect on the subject.
These terrific thunderbolts of Jupiter seem
in general to have come down to the earth
accompanied by such loud explosions, blazes,
and other circumstances as in a less degree
attend the larger sort of fiery meteors. In-
deed all these meteors may be owing to
some common principle of chemical action
going on in the higher regions of the atmos-
phere; which, when more gentle and slow,
may only cause the blazing meteors; but
which, when more intense, may go on to
128 OF AEROLITES. CHAP. 3, § 2.
&
consolidate large masses of newly composed
substance, and may manifest itself by the
fall of ačrolites. I see no necessity for sup-
posing with Aristotle and M. De Luc that
the gasses, to form the meteors, should ascend
from the earth, nor any proof of their
ascent; but it may be by means of gasses
somewhere formed aloft and taking fire that
the meteoric stones are formed. The way
in which electricity may be concerned in
their processes is at present unknown; and
the number of accounts of the fall of these
stones, and of hypotheses about their causes,
are too numerous to render a detail of them
here of any utility. I merely wish to call
the attention of meteorologists to the appa-
rent similiarity of principle of those blazing
meteors which are, and of those which are
not, visibly attended with the fall of aerolites.*
* For analyses of aerolites, see Thomson's System
of Chemistry, Phil. Mag, etc. For further particulars .
see also the Chap. on Electricity.
Chap. 4, OF PROGNOSTICKs. 129
# CHAPTER IV.
of INDICATIONS OF FUTURE CHANGES OF
WEATHER.
ONE of the principal uses of meteorology
is, that it enables us to predict, in some
measure, the ensuing changes of the wea-
ther. To do this accurately, a familiar ac-
quaintance with the modifieations of the
clouds, and indeed with all the operations
which are going on above, appears neces-
sary. I hardly need lay down the following
rule for predicting atmospheric changes,
That when two or more contrary indications
appear, the result must be deduced from
those which ultimately prevail; and that
when several agreeable signs appear, the
event may be considered as predicted with
additional certainty.” Prognosticks of wea-
* A rule laid down of old and sung by Aratus, who
says of Prognosticks, *
*Tºy wºw hoſloxy)ad woºow, 3’etri Gºſport, Gººg
Xuanliaº, Psaxov be ºvdiv, eig ladlow ſovrov
Extaph reasºol" 1plité 3s sº £apongelo.g.
K
Arat, Dios, 412.
130 OF PROGNOSTICKS. CHAP.4.
ther may be divided into those which result
from the observance of the sky, and of
meteorological instruments; and those which
are deducible from the motions and habits of
particular animals, plants, etc. • ,
The popular prognosticks of rain, wind,
and other changes of weather, which with
little variety are common in most countries,
seem to have been known and observed with
accuracy of old. Indeed their being familiar
to almost every age and country affords the
strongest confirmation of their correctness, to
those who have not had constant experience
of them. Although we find familiar mention
of the signs of the weather among almost
all the oriental writings, yet Theophrastus,
the Grecian naturalist, seems to have been
the first who cultivated this branch of meteo-
rological science, and collected together
the proverbial rules of judging of the wea-
ther; which were shortly afterwards put into
verse by Aratus the poet in his Aloanwela,
above two thousand one hundred years ago,
and are imitated by Virgil, Lucan, Pliny,
Seneca, and others. With little variation,
the same rules are found scattered among
numerous works of natural history and
Chap. 4, § 1. OF PROGNOSTICKs. 131
and science. And they are popular among
the lower classes of modern Europe. Such
of them as I have collected by occasional
conversation with persons who spend their
lives chiefly out of doors, and who are
attentive in noticing their prognosticks, or
what I have noticed myself, I have here
collated with the written accounts of the
ancients.
SECTION I.
Of Prognosticks of A tmospheric Changes, dedu-
cible from the Motions of Animals.
IT was long ago observed by the ancients
that, from the peculiar motions and habits of
many animals, the consequence, probably, of
their sensations of pain or of pleasure, a very
accurate judgment might be formed of the
approaching changes of the weather; neither
has this entirely escaped the notice of more
modern meteorologists. But I think they
have not bestowed that share of attention to
this subject which it certainly deserves. It
is difficult, perhaps, to conceive the manner
in which animals become sensible of the
approach of particular kinds of weather. We
K 2
132 OF PROGNOSTICKS. CHAP:4:51.
cannot suppose that they are forewarned of
it by the appearances of the sky, at least in
many cases; for some animals express signs
of uneasiness previous to an alteration of the
weather, long before there are any visible
signs of change, and often when they have
no opportunity of observing what is going
on abroad. Dogs, for instance, closely con-
fined in a room, frequently become very
drowsy and stupid before rain. They often
sleep all day before the fire, and are almost
incapable of being roused.* The same, in
a less degree, is observable in cats. And a
leech, confined in a glass of water, has been
found, by its rapid motions, or its quiescence,
to indicate wet or fair weather. From an
examination of the structures of the brain of
animals, they do not appear organized to
have any notions of causation; but they
observe that two things are together, or
follow one another; thus from one they anti-
cipate and prepare against another. Their
prognostication, however, of weather seems
to result rather from some impressions on
* On such occasions, I have sometimes found their
ears considerably inflamed, a common symptom of ill-
health in many animals.
ſº
Chap. 4. §1. OF PROGNOSTICKS. 133
their feelings, than from any observation of
what is going on in the sky.” Peculiarities
in the electric state of the atmosphere may,
I think, be supposed to affect the constitu-
tions of animals in the same manner as they
appear to do ours, and may thereby excite
pleasurable or uneasy sensations.#
Rain may be expected, when the swallow
flies low, and skims backward and forward
over the surface of the earth and waters,
frequently dipping the tips of its wings into
the latter.j.
* It is a pity that among all our works of comparative
anatomy, we have actually no accounts of the structure
and organs of the brain of different animals. The disco-
veries of Galland. Spurzheim seem likely to throw some
light on this most interesting part of natural history.
+ “Haud equidem credo quia sit divinitus illis.
Ingenium, aut rerum fato prudentia major;
Verum ubi tempestas et coeli mobilis humor
Mutavére vias, et Jupiter uvidus austris
Denset erant quae rara modo, et quae densa relaxat,
Vertuntur species animorum, et pectora motus
Nunc alios, alios dum nubila ventus agebat,
Concipiunt; hinc ille avium concentus in agris
Et laetae pecudes-et ovantes gutture corvi.”
Wirgil. Georg. lib. i.
# Among the signs of rain, Pliny enumerates Hi-
rundo Éam, justa aquam voktans ut penna saepe percutiat.
See also Obser. Brum. Retr. Swal. 38. Edit, London;
1813. *
134 OF PROGNOSTICKS. CHAr. 4: $1.
When bees do not go out as usual, but
keep in or near to their hives,” or when
ducks, geese, and other water fowl, are un-
usually clamorous, we may also expect wet.
Before rain, swine, as well as poultry,
appear very uneasy, and rub in the dust.
Before and during rain, ducks, geese, and
other fowls wash and dive in the waters
more than usual. Pidgeons also wash before
rain; and cats wash their faces; they have
been observed also to scratch the bark off
trees. In autumn, flies sting and become
unusally troublesome.
Dogs, and other domestic animals, like-
wise express signs of uneasiness, and are
very sleepy and dull before rain and snow.
Dogs are said to dig great holes in the
ground in rainy weather. We had a dog
always busy in digging deep cayerns in
* “ Nec vero a stabulis, pluvia impendente recedunt
Longius, aut credunt coelo adventantibus Euris
Sed circum tutae sub moenibus urbis aquantur,
Excursusque breves tentant.”
Virg. Geor. lib. iv. 194.
"H Aluyºy region&a zeabove; &la awaii.
Tarpi rviflovoz &vrog slavuevoy Joãg.
Arat. Dios.
Theophrastus observes as a sign of rain x=xidows; tº yarp,
wnlovo, tag Aluvas. Linnaeus also notices this prognos-
tick shaking of hirundo rustica. r
CHAP.4. § 1. OF PROGNOSTICKS. 185
the earth which he laid in during particular
kinds of weather. This dog was a cross
breed between a pug and terrier, remarkable
for his sagacity. f
If abroad, after long continued dry
weather, when the sky is thickening, and
rain approaching, we may frequently ob-
serve the cattle stretching out their necks,
and snuffing in the air with distended nostrils;
and often, before storms, assembled in
a corner of the field, with their heads to
the leeward.”
The loud and continued croaking of frogs
heard from the pool; the squalling of the
pintadot and the peacock, and the appearance
of spiders crawling on the walls more than or-
dinary, and the coming forth of worms, have
also been considered as signs of rain. Most of
these have been noticed by Virgil, who has
likewise added several more, which have
never fallen under my notice,; but which
* Boves coelum olfactantes seque lambentes contra
pilum. Plin. Hist. Nat. xviii. 35.
+ This bird is called the comeback in Norfolk, and
regarded as the invoker of rain. It often continues
clamorous throughout the whole of rainy days.
f — “ Numquam imprudentibus imber
Obfuit, aut illum surgentem vallibus imis
Aeriae fugere grues, aut bucula coelum
* *
^.
136 OF PROGNOSTICKs. Car.. $1.
*
have been mentioned by many writers, both
ancient and modern:* When cocks crow at
uncommon hours, and clap their wings a
great deal, it is said to be a sign of rain ; as is
the appearance of the redbreast near houses.
Suspiciens patulis captavit naribus auras
Aut arguta lacus circumvolitawit hirundo
Et veterem in limo ranae cecinere querelam.
Saepius et tectis penetralibus extulit ova
Augustum formica terens iter, et bibitingens
Arcus, et e pastu decedens agmine magno
Corvorum increpuit densis exercitus alis.
Jam varias pelagi volucres et quae Asia circum
Dulcibus in stagnis rimantur prata Caystri
Certatin largos humerisinfundere rores
Nunc caput objectare fretis nunc currere in undas
Et studio incassum videas gestire lavandi,
Tum cornix plena pluviam vocat improba voce
Et sola in sicca secum spatiatur arena
Nec nocturna quidem carpentes pensa puellae
Nescivere hyemem testa quum ardente viderent
Scintillare oleum et putres concrescere fungos.
Wirg. Geor. lib. I. 392.
Cornicum ut saecla vetusta
Corvorumque greges ubi aquam dicuntur et imbres
Proscere et interdum yentos aurasque vocare.
Luctet. de Rer. Nat. v. 1085.
Et quum terrestres volucres contra aquam clangores
dabunt, perfundentessese, sed maxime cornix.
Plin. xviii. 35.
Rava fulix itidem fugiense gurgite ponti
Clamans nunciat horribles instare procellas
Haud modicos tremulo fundens ex gutture cantus
3&
CHAP. 4. § 1. OF PROGNOSTICKS. 137
Sparrows chirp particularly loud during
rain, and often begin before it falls, affording.
thereby for some time previously a prog-
nostick of its coming.
If toads come from their holes in great
numbers; if moles throw up the earth
more than usual ; if bats squeak or enter
the houses; if asses shake their ears and bray
much; if hogs shake and destroy the corn-
stalks; if oxen lick their forefeet, or lay on
their right side; or if mice contend together
or squeak much, according to many authors
we may expect rain. Sheep and other cattle
gamboling or running about and appearing
very uneasy also portend rain.
Sometimes previous to rain sheep and goats
seem more desirous to graze, and quit with
reluctance their pastures.
Saepe etiam pertriste canit de pectore carmen
Et matutinis acredula vocibus instat
Vocibus instat et adsiduas jacit ore querelas
Quum primum gelidos rores Aurora remittit
Fuscaque nonnumquam cursans per littora cornix
Demersit caput et fluctum cervice recepit.
Cicero eac Arat. de Div. lib. 1.
HTs wou xxxipvºo, waff hiów weekson
Xsporos apxop.svg xépo'º wrewºg nopavn.
Arat. Dios. 217.
see also Aelian de Anim. viii. 7.
H38 OF PROGNOSTICKS. Char. 4. $ 1.
Among other things the activity of ants
in carrying about their eggs,” the voice
of the solitary crow,t and the frequent
immersion of many water fowl have
been considered as indications of rain.
The garrulity of crows, ravens, rooks,
and other birds of this sort, is indeed well
known; “corvus aquat" is a proverb cited by
Erasmus. But we must distinguish be-
tween the voice of the raven before rain,
perched solitary on a tree and uttering a
harsh cry, from his deep and peculiarly mo-
dulated voice when sailing round and round
high up in the air before and during serene
weather.|| The raven as well as other birds
often soars at an elevation much beyond
what we are apt to imagine. When at the
top of Cader Idris near Dolgelly I observed
these birds flying considerably above the
summit of that mountain on which I sat.
The hooting and screeching of owls often
* Formicae concursantes autova progerentes.—Plin.
f Horat. Carm. lib. iii. Od. 17. l. 13.−Od. 27. l. 9.
—Claudian. xv. 493.−Lucan. v. 555.
f Plin, lib. xviii. 35.-Arat. Dios. 210.-Homer. Il.
8.461.-Varr. Frag. Catelect.
| For numerous collateral passages about this and,
other prognosticks I must refer to my edition of the
Diosemeia of Aratus.
Chap. 4. § 1. OF PROGNOSTICKS. 139
*
indicates a change of weather. They hoot in
fact during variable weather: when fair is
about to be changed for wet, or wet for
fair, a similar disturbance of their feelings
from atmospherical causes probably makes
them hoot. Refer to Virgil's observation in
Georg. lib. 1. and Professor Heyné's note on
them. Authors have added, the snapping
of the flame of a candle or lamp, men-
tioned by Aratus and Virgil, as a sign of
Wet.
Hesiod mentions the singing of a bird,
which he calls xv, xvá, as foreboding three
days' rain; and a Leipzick editor renders the
word cuculus; on what authority I know
not.* ~,
The missile thrush, turdus viscivorus, fre-
quently sings particularly loud and long be-
fore rain. I have known this bird sing
throughout a severe storm. - It is from this
circumstance called the storm fowl.
Mariners at sea expect a storm when the
procellariae pelagicae, or stormy petrels,
* Hºo: www3 wounvće 3ovos ey reráºolai
To wedlov, Teers, re 8pots; it’srsipovo, Yaſaw,
Thwo; Zev; 'vo, Terra mººr, whº aroxyou. -
Hesiod, Op. et Dies. 488.
140 OF PROGNOSTICKS. CHAP.4. §h.
shelter themselves in numbers under the
wake of the vessel.” -
Pennant observes that on the Island of
St. Kilda the procellaria glacialis is very
useful in foreboding the direction of the wind.
When these birds return to the land in num-
bers there will be no west wind for a long
time; when, on the contrary, they return to
the ocean a west wind is expected. Seve-
ral prognosticks of storms are mentioned by
the old Greek writers which are not observed
on our shores, neither do we know exactly .
what birds they alluded to. I have observed
that previous to windy weather pigs seem
very uneasy and running about throwing
up their heads and squeaking,
Magpies before and during wind fly about
in small companies, and make a fluttering
noise. *
When the seagulls come in numbers to
shore, and make a noise about the coast;
or when, at sea, they alight on ships, the
sailors consider it a sure foreboding of a
storm. These circumstances were known
of old. Before storms, too, the porpus,
* Bewick’s Birds, 2nd vol. of Waterfowl. 24.
+ Pennant's Arctic Zool.
# Virg, Geor, lib. 1–Plin, lib, xviii, c. 35.
CHAP.4. $2. OF PROGNOSTICKs. 141
dolphin, and grampus, come to the shore in
large bodies.
When dolphins play about the surface of
a calm sea, Pliny observes wind may be
expected from that quarter from which they
have come.* Authors have added tame
swans, flying against the wind, as a sign of
Tºlºſ?.
SECTION II.
Qf Prognosticks of Weather taken from the
Observance of Plants and Flowers, etc.
IN the oeconomy of nature we find that
plants, like animals, adapt their motions
to their wants: some expand their flowers to
the Sun, and close them at eventide; others
expand their flowers in the evening, open
before rain, or perform various other func-
tions, the result of their particular natures,
and to which the varying states of the atmo-
sphere are specific stimuli. From an accurate
and constant observance of these many prog-
nosticks of the ensuing weather have been
deduced; of which I insert the following,
* Plin. Hist. Nat, lib, xviii. 35.
142 OF PROGNOSTICKS. CHAP.4. §2.
rather on account of their popularity, than
because I have noticed many of them
myself.
Chickweed has been said to be an excel-
lent weatherguide: when the flower expands
freely, no rain will fall for many hours; if it
so continues open, no rain for a long time
need be feared. In showery days the flower
appears half concealed, and this state may
be regarded as indicative of showery wea-
ther; when it is entirely shut we may expect
a rainy day.
If the flowers of the Siberian sowthistle
remain open all night, we may expect rain
next day.
Before showers the trefoil contracts its
leaves,” as does the convolvulus and many
other plants. *
Lord Bacon observes that the trefoil has
its stalk more erect against rain.
There are many plants whose flowers
are opened at particular periods of the day,
as the tragopogon porrifolium and pratense;
which open their flowers earlier or later,
according to the state of the weather.
Lord Bacon mentions a small red flower,
growing in stubble fields, called by the
* Plin. Hist, Nat. xviii. 35.
CHAP.4. 53. OF PROGNOSTICKS. 143
country people wincopipe, which if it opens
in the morning ensures us a fine day.
To these, the closing of the flowers of the
pimpernel, and numerous other prognosticks,
might be added, but it would swell this
section beyond its limits.” g
SECTION III.
Of the Prognosticks of JWeather from the Ap-
pearances of the Sky.
After clear weather the appearance of
light streaks of cirrus in the sky is often the
first sign of a change. These increase, des-
cend, become cirrostrati, cumuli form under-
neath and inosculate, and nimbus and rain
are the event of the process begun by fine
filaments of the cirrus.
When the cirrus is seen in detached tufts,
called Mares' Tails, it may be regarded as a
sign of wind, which follows often blow-
ing from the quarter to which the fibrous
tails have previously pointed. The change
from cirrus to cirrostratus, and indeed
* The reader may consult Lord Bacon's Sylva Sylva-
rum, cent, ix. cap. 823–830.
A.
&#
144 OF PROGNOSTICKS. Char.4.5 s.
the great prevalence of the latter cloud at
any time must be regarded as an indication
of an impending fall. The most formidable
features of cirrostratus are the large spread-
ing and dense sheets of it which veil the sky
before rain, and in which the sun often sets
shrouded against a rainy day.
The prevalence of clouds of the modi-
fication of cirrostratus at eventide had been
noticed as a sign of rain long before the
specific nature of the different clouds was
attended to; and the vivid colours of red
and crimson seen in this cloud when the sun
is near the horizon, give rise to many pro-
verbs about the red evening, and its favour-
able omen to the traveller; a remark quite
as trite among country people, as the grey
morning before a fair day. This, as well as
the redness of the morning, as indicative of
a fair day, is noticed by St. Matthew, in
chap. xvi. 2. Dappled grey mornings, or
those marked by the lofty confluent nube-
culae of cirrocumulus, often usher in a
fair warm day.” Indeed the appearance of
* An old proverb reminds us,
An evening red, and a morning grey,
Are sure signs of a fine day;
But an evening grey, and a morning red,
Put on your hat, or you’ll wet your head.
CHAP. 4. § 3. OF PROGNOSTICKS: 145
cirrocumulus in general indicates an increase
of temperature. Heyne, in his edition of
Virgil, speaks of them as being called
oviculae or little sheep, from their appear-
ance, and as indicating fair weather.”
The denser features of cirrocumulus, or
those whose nubeculae are dense, compact,
round, aggregate, are generally indicative of
a Storm.
Before storms too a feature of cirrostratus
appears, of a cymoid figure, like some archi-
tectural ornaments. Pl. IV. Fig. 1.
It is generally in variable weather that a
line of cirrostratus breaks out into transverse
bars, as in Pl. II. Fig. 2. •
The irregular increase of cumuli, particu-
larly toward evening; and in general their
not subsiding in the evening, may be regard-
ed as a forewarning of wet.
The Italians have:
Sera rosa e nigro matino
Allegra il Pelegrino.
* Among the many rules, such as are contained in our
old almanacks, we find *
If woolly fleeces strew the heavenly way,
Be sure no rain disturb the summer day.
Virgil and Aratus, however, made the vellera lange
rainy signs, and meant, do doubt, cirrus or cirrostratus.
T.
146 .*
ÖF PROGNOSTICKS. Char.4. $6.
When cumuli sailing along have their
fleecy protuberances curling inward, variable
weather may be expected, such cumuli often
rapidly anastomose with cirri or cirrostratus
above them, and produce showers.
When a dense and uniform veil of cloud
covers the sky, as is often the case before
rain, with a still air, musick and noises are
heard a great way off, which has caused the
far propagation of sounds to be regarded as
a prognostick of rain. The sound of distant
church bells in the country often serves this
prognosticative purpose.
In Wales the common people say, that
when the mountains have their nightcaps
ôn, the rain will soon fall.
While I was in Wales during a showery
time, the peaks of the mountains were gene-
rally capped with clouds of the low and
nimbiform kind. The clearness of the tops
of mountains is, on the contrary, a sign of
the fairness of the weather. Long cirrostrati
and other elevated clouds often alight on the
summit of real mountains, as they do on
mountainlike cumulostrati, and are equally
indicative of wet weather. 4
When the rapid formation and disappear-
CHAP. 4. § 3. OF PROGNOSTICKS, 14?
ance again of clouds take place in fine days,
as is often the case, we may suspect the sere-
nity we enjoy, and look forward to a change.
I have seen little cumuli form and disappear
in the space of a few minutes; and cirrus
form, change its figure to spots of cirrocu-
mulus, and disappear at the same time at a
more elevated station. *
Luminous phaenomena about the sun by
day, or the moon by night, being generally
produced by the intervention of cirrostratus,
indicate the fall of rain, snow, or hail, ac-
cording to circumstances; indeed, many of
the signs of rain are likewise under other
circumstances of time of year, &c. prognos-
tieks of snow. The halo is one of the most
certain signs of rain we have; though I have
even known this failin its accustomed indica-
tion. The parhelion and other peculiar re-
fractions also forebode rainy weather:*
The simple corona often occurs in many
kinds of thin clouds, and frequently without
any rain following; but we may generally
expect wet when it is coloured, double, or
$ Consult Arist. Meteor. lib. iv.cc, 3–6; the Dios. of
Aratus; the Natural History of Pliny; the Natural Quest.
of Seneca, etc.
L 2
148 OF PROGNOSTICKS. CHAP. 4. $3.
with any remarkable peculiarities. We do
not know at present under what peculiar cir-
cumstances halones and coronae are coloured;
but it must be done by something particular
in the structure of the cloud which produces
them.
The halo appears at times in a sky where
there is little or no visible obscuration, the
interstitial space between the rings seems
quite blue, like the sky in general. Some
very fine diffused haziness, perhaps cirro-
stratus, however produces by refraction the
white ring of the phaenomenon. We often
find on such occasions the light of the stars
dim, and a more complete obscuration, and
eventually rain to follow. Pliny has noticed
this obscuration of the light of the Sun by day,
and of the stars by night, without any definite
cloud, to forebode rain, as had been before
mentioned by the more ancient writers.”
The rainbow, which is only an effect
* See Plin. Hist. Nat. lib. xviii. c. 35. The rain which
falls under such circumstances is gentle and of long con-
tinuance, and often extends a great way. The vulgar
prejudice, however, about the extent of rain in general
is quite unfounded. H. Culhwe Mabinogion, in allusion
to this:—Ti à gefiy cyvarws a moto dy ben à th davawd,
hyd y syc gwynt, hyd y gwlyc, gwlaw hyd y treigl haul
a hyd yz amgyfred mór. *
Chap. 4. $4. OF PROGNOSTICKS. 149
of nimbus, has been regarded as a sign of
rain; which it may rightly be, for it often
appears in the nimbus before that cloud,
weeping in his sable shrowd, has reached the
spot where we stand. Bibit ingens arcus,
says the Mantuan bard, who took most of
his prognosticks from the Diosemea of
Aratus.*
Of the particular indications of the haze in
the atmosphere we may notice, that the
mere hazy or pale colour of the moon often
forebodes rain, while she is more brazen,
red, or copper coloured before wind. This
corresponds with the red in the clouds, be-
fore noticed as a sign of wind.
SECTION IV.
Of several other Prognosticks of Rain, and of
the Return of fair Weather.
Many indications of atmospheric changes
have been noticed by different authors, which
* Hºupºn iºs Six utyay Supavoy ipl;
Huai trou rig gawa Peñalvop syny, sus, arnº.
Arat. Dios. 210.
See also Virgil, Geor. i. 380. Platus Curcul. Statius
Thebaid, ix. 405.
#50 OF PROGNOSTICKS. Char, 4.54.
I have not determined by my own observa.
tion to be correct, such, for example, as the
smell of drains and suspools; the excrescence
of fungi about the wicks of lamps and can-
dles; the flaring and snapping of the flame;
the soot taking fire in sparks round the
smoky outside surface of a pot on the fire;
the wicks of candles not being easily lighted,
and many others of this sort. Wind has been
indicated by candles burning unequally, or by
coals casting off more ashes than usual.
Pain felt in limbs formerly broken, or in
other injured parts of the body, oftenforebode
rain. In the summer of 1818, the extensor
tendon of my forefinger was divided by
accident, and though by means of a new
substance interposed between the divided
ends of the tendon, its functions were restor-
ed, and the wound completely healed, yet I
always feel an uneasy sensation in it before
rainy weather, very similar to that which I
experience after having much exerted it.
The cumulostratus being a state of the clouds going on
to become nimbus, has been regarded as one of the rainy
signs, and given rise to the following adage:
“When clouds appear like rocks and towers,
The earth's refreshed by frequent showers,”
1.
CHAP. 4, §5, QF PROGNOSTIGKS, 151
SECTION W.
Qf Indications of the Return of Fair Weather.
THE absence of those circumstances which
forebode or accompany foul weather may
generally be considered as indicating a return
of fair. So Virgil mentions the clear and
bright appearance of the moon and stars,
after they have long been hazy and confused,
to indicate approaching serenity.” Every
one is acquainted with the additional clear-
* Nec minus ex imbri soles et aperta serena
Prospicere et certis poteris cognoscere signis
Nam neque tum stellis acies obtusa videtur
Nec fratris radiis obnoxia surgere luna
Tenuia mec lanae per coelum wellera ferri
Non tepidum ad solem pennas in littore pandunt
Delectae Theydi halcyones, non ore solutos
Inmundi meminere sues jactare maniplos.
At nebulae magis imapetunt, campoque recumbunt;
Solis et occasum servans de Gulmine summo
Nequidquam seros exercet noctua cantus.
- Virg. Geor. i. 403.
-Tum liquidas corvi, pressoter gutture voces
Aut quater ingeminant, et saepe cubilibus altis
Nescio qua praeter solitum dulcedine laeti
Inter se foliis strepitantjuvatimbribus actis
Progeniem parvam dulgesque revisere nidos.
Wirg. Geor, i, 414.
152 OF PROGNOSTICKS. CHAP. 4, § 5.
ness of a night intervening between wet and
clear frosty weather. By the general dis-
position of the clouds, we may, in general,
prognosticate fair or rainy weather. In the
most settled weather, only diurnal, cumuli
appear; they are well defined, increase to-
wards the middle of the day, and decrease at
night. Of this enough has been already said
in the chapter on the clouds. The bright-
ness and heat of the fire in winter often
indicate frosty and clear weather, as does the
lodgment of the moisture on the windows;
for it demonstrates a cold and frosty atmo-
sphere abroad.* To the above signs of at-
mospheric changes, many others might be
added; but to enumerate all which different
authors have mentioned, would swell too
much this chapter, and I must refer the reader,
for further information on this subject, to
the chapter on superstitions originating in
meteorological phaenomena, wherein I have
collected and inserted more of these trite
* See the Shepherd of Banbury's Calendar, London,
1748. t
Lord Bacon has adduced many conjectures why herons
flying high forebode wind, and kites doing the same, fair
weather.
Char, 4.56. OF PROGNOSTICKs. 153
and ancient sayings about the prognosticks
of the weather.
SECTION WI.
Of the Prognosticks of Seasons.
THE constant desire to know what is
about to happen, which our natural curiosity
and the interest we take in future events oc-
casion, added to the use which agriculturists
and farmers may make of some knowledge
of the approaching weather, have always
rendered men very attentive to the signs of
the seasons; and made them watch atten-
tively for those circumstances from which
experience had taught them to anticipate
severe winters, hot summers, late springs,
plentiful autumns, and other vicissitudes
of the year.
Lord Bacon, who was so well calculated to
observe and compare facts, collected nume-
rous prognosticks of this sort," which are re-
corded among his works on natural history.
I shall mention a few of these as subjects
$54, OF PROGNOSTICKS. CHAP, 4.56.
for future observation; though, as far as my
own experience goes, the cases of exception
are nearly as numerous as those which corre-
spond with the rules. According to Bacon, a
moist and cool summer bodeth a hard winter;
a hot and dry summer and autumn portendeth
an open beginning of the winter, and a cold
midwinter and spring; an open and warm
winter presageth a hot and dry summer, par-
ticularly when there are winter showers.
The earlier or later appearance of birds
of passage is said to correspond with the
earlier or later commencement of the sea-
sonable weathers; and to afford thereby a
prognostick. But for many years I have
observed that this is not precisely the case
with the swallow tribe. If it were generally
true it would tend to establish a connexion
between the weather of places where the
birds come from and that of those countries.
whither they go. But when the later appear-
ance of migratory fowls accompanies late sea-
sons, it is probably because the cold unsea-
sonable weather compels them to hide them-
selves and prevents their coming abroad and
being seen. The occasional early appear-
CHAP. 4. $6. OF PROGNOSTICKS. 155
ance of a single swallow has been prover-
bially noticed as not being indicative of
summer.” & *
Mr. White in his Natural History of Sel-
borne has given a list of the times of the
first appearance of migratory birds for seve-
ral years: and I have given tables of
their appearance in Nicholson's Phil. Jour.
and in my Observations on the Brumal
Retreat of the Swallow, 3d edit. Appendix;
whereby the reader, by comparing the
birds' appearance with the seasons, may ob-
tain some information on this point.
The abundance of berries in the hedges
is said to presage a hard winter, but this often
fails.
* It is remarkable, that most countries have a similar
proverb relating to the swallow's accidental appearance
before its usual time. The Greeks have Mix xxºy
#xg 3 wois ; the Latins, Unahirundo non facit ver; the
French, Une hirondelle me fait pas les printems; the
Germans, Qºirie gºûâûibe mºtiºt Heinen frttling; the
Dutch, Een swaluw maakt geen Zomer; the Swedes,
‘En svala går ingen sommar; the Spanish, Una golon-
drina no hace verano; the Italians, Una rondine non fa
primavera; and the English, One swallow doth not
make a summer.
I56 of PROGNOSTICKs. Char.4, 37.
SECTION VII.
Of Solar and Lunar Influence.
The influence of periods of day and night
on many diseases which have been incontro-
vertibly proved, and the recurrence of many
after certain intervals of time, show that
there is some truth in the notions of many
physiologists about periodicity; and that this
is probably effected by means of some un-
known changes produced in the weather. We
do not know yet what regulates atmospheric
changes in general; how electricity becomes
so distributed as to produce those various
effects which analogy leads us to ascribe to
it; in short, we have no good general theory
of meteorology, as we have of astronomy,
mechanics, &c. The old notions of astrolo-
gers about the conjunctions of planets in-
volve too many palpable absurdities to allow .
us to collect any useful information from
their writings.
But it is certain the place of the moon
has some influence on the weather. That
changes of weather oftner take place about
CHAP. 4, §8. OF PROGNOSTICKS. 15?
the full and new moon and about the quadra-
tures, than at other times, is really a fact
founded on long observation.*
SECTION VIII.
Proverbs relating to the Months, Seasons, etc.
ProverBIAL phrases and adages are gene-
rally founded on observation, and these are
the less likely to be compared with false and
vain theories, because they are the philoso-
phy of the unlettered hinds, who have no-
thing but experience to go upon in establish-
ing rules. That the reader may judge from
time to time how far any of these are
correct, and may compare them with his
own experience, I insert the following, most
of which were collected by Ray.f
* A Proverb says:
In the decay of the moon
A cloudy morning bodes a fair afternoon.
Also. Rain in the new moon, fair in the old. &c.
See Ray's Collection of Proverbs, and Erasmi Adagia.
+ See also an entertaining book called Time's Teles-
cope, published in 12mo, in London last year, p. 358.
158 GF PROGNôSTICKs, Cº. 4,38,
-
Janiveer freese the pot by the fire. . . . . . .
If the grass grow in Janiveer,
It grows the worse for't all the year.
Who in Janiveer sows oats, gets gold and groats,
Who sows in May, gets little that way. --
If Janiveer calends be summerly gay,
*Twill be winterly weather till the calends of May.
On Candlemasday throw candle and candlestickaway.
When Candlemasday is come and gone, w
The snow lies on a hot stone.
February fill dike, be it black or be it white:
But if it be white, it's the better to like.
Februeer doth cut and shear. *
The hind had as lief see his wife on the bier,
As that Candlemasday should be pleasant and clear.
February makes a bridge, and March breaks it.
March in Janiveer, Janiveer in March I fear.
1March hack ham, comes in like a lion, goes out like &
lamb. * •
A bushel of March dust is worth a king's ransom. ==.
March grass never did good. ... "
, , , , / A windy March, and a rainy April, make a beautiful May.
A March wisher is never a good fisher. -
March wind and May sun, make clothes white and maids
dun. *
So many frosts in March, so many in May.
March many weathers. f
March birds are best.
April showers bring forth May flowers.
Chap. 4.55. QF PROGNOSTICKS. 1.59
( :
Chaucer writes in his Cañterbury tates:—
When that Aprilis with her showery soote
The droughte of March had pierced to the roote.
When April blows his horn, it's good both for hay and
COTIls
A cold April the barn will fill.
An April flood carries away the frog and her brood.
A cold May and a windy, makes a full barn and a findy.
The merry month of May.
April and May are the keys of the year.
May, come she early or come she late, she'll make the
cow to quake.
Beans blow before May doth go.
A May flood never did good.
Look at your corn in May, and you’ll come weeping
away.
Look at the same in June, and you'll come home in
another tune. *
Shear your sheep in May, and shear them all away.
A swarm of bees in May is worth a load of hay;
But a swarm in July is not worth a fly.
Calm weather in June sets corn in tune.
If on the eighth of June it rain,
It foretells a wet harvest, men sain.
If the first of July it be rainy weather,
*Twill rain more or less for four weeks together.
A shower in July, when the corn begins to fill,
Is worth a plough of oxen, and all belongs there till.
No tempest, good July, lest corn come off blue by.
Dry August and warm, doth harvest no harm.
160 of PROGNOSTICKs. Char.4.5 s.
If the twentyfourth of August be fair and clear,
Then hope for a prosperous autumn that year.
September, blow soft, 'till the fruit's in the loft.
Good October, a good blast,
To blow the hog acorn and mast.
November take flail, let ships no more sail.
When the wind's in the east, it's geither good for man
nor beast. -
When the wind's in the south, it's in the rain’s mouth.
When the wind’s in the south,
It blows the bait into the fishes' mouth.
No weather is ill, if the wind be still.
A hot May makes a fat churchyard.
When the sloetree is as white as a sheet,
Sow your barley whether it be dry or wet.
A green winter makes a fat churchyard.
Hail brings frost in the tail.
A snow year, a rich year.
Winter's thunder's summer's wonder.
Drought never bred dearth in England,
Whoso hath but a mouth, shall ne'er in England suffer
drought.
When the sand doth feed the clay, ,
England woe and welladay.
But when the clay doth feed the sand,
Then it is well with England.
After a famine in the stall,
Comes a famine in the hall.
When the cuckoo comes to the bare thorn,
Sell your cow, and buy your corn:
CHAP.4. § 8. QF PROGNOSTICKs. 161
But when she comes to the full bit, &
Sell your corn, and buy your sheep.
If the cock moult before the hen,
We shall have weather thick and thin;
But if the hen moult before the cock,
We shall have weather hard as a block. .
As the days lengthen, so the cold strengthens.
If there be a rainbow in the eve, it will rain and leave.
But if there be a rainbow in the morrow, it will neither
leed nor borrow.
A rainbow in the morning
Is the shepherd's warning.
But a rainbow at night
Is the shepherd’s delight.
When the clouds are upon the hills, they’ll come down
by the rills.
Winter's thunder, and summer's flood,
Never boded Englishman good.
If Candlemasday be fair and bright,
Winter will have another flight:
If on Candlemasday it be shower and rain,
Winter is gone, and will not come again.
I insert in conclusion the well known
rules of the Shepherd of Banbury.
If the sun rise red and fiery, wind and rain.”
If cloudy and it soon decrease, certain fair weather.
r—t
* The same is observed of the moon, of whose three,
several indications the adage says,
Pallida luna pluit, rubicunda flat, alba serenat.
M
162 OF PROGNOSTICKS, CHAP.4. §8.
Clouds small and round, like a dapple grey with a
north-wind, fair weather for two or three days.
Large clouds like rocks, forebode great showers.
If small clouds increase, much rain.
If large clouds decrease, fair weather.
Mists, if they rise in low ground and soon vanish,
fair weather,
ſf mists rise to the hilltops, rain in a day or two.
A general mist before the sun rises, near the full
moon, fair weather.
If mists in the new moon, rain in the old.
If mists in the old, rain in the new.
Observe that in eight years time there is as much south-
west wind, as northeast, and consequently as many wet
years as dry.
When the wind turns to northeast, and it continues
two days without rain, and does not turn south the
third day, nor rain the third day, it is likely to continue
northeast, for eight or nine days, all fair; and then to
come to the south again.
If the wind turns again out of the south to the north-
east with rain, and continues in the northeast two days
without rain, and meither turns south, nor rains the
third day, it is likely to continue northeast for two or
three months.
After a northerly wind for the most part two months
or more, and then coming south, there are usually three
or four fair days at first, and then on the fourth or fifth
day comes rain, or else the wind turns north again, and
continues dry.
If the wind returns to the south within a day or two
without rain, and turn northward with rain, and return
to the south, in one or two days more, two or three times
together, after this sort, then it is likely to be in the
south or southwest, two or three months together, as it
was in the north before.
CHAP. 4. §8. OF PROGNOSTICKS. 163
Fair weather for a week, with a southern wind, will
produce a great drought, if there has been much rain
out of the south before. The wind usually turns from
north to south, with a quiet wind without rain, but
returns to the north with a strong wind and rain. The
strongest winds are when it turns from south, to north,
by west.
Clouds. In summer or harvest, when the wind has
been south two or three days, and it grows very hot, and
you see clouds rise with great white tops like towers, as if
one were upon the top of another, and joined together
with black on the nether side, there will be thunder and
rain suddenly.”
If two such clouds arise, one on either hand, it is
time to make haste to shelter.
If you see a cloud rise against the wind or side wind,
when that cloud comes up to you, the wind will blow the
same way that the cloud came. And the same rule holds
of a clear place, when all the sky is equally thick,
except one clear edge.
Sudden rains never last long: but when the air grows
thick by degrees, and the sun, moon, and stars shine
dimmer and dimmer, then it is likely to rain six hours
usually.
If it begin to rain from the south, with a high wind
for two or three hours, and the wind falls, but the rain
continues, it is likely to rain twelve hours or more, and
does usually rain till a strong north wind clears the air.
These long rains seldom hold above twelve hours, or
happen above once a year.
If it begin to rain an hour or two before sun rising, it
is likely to be fair before noon, and so continue that day:
but if the rain begin an hour or two after sun rising, it
* This is the formation of cumulostratus.
M 2
164: of PROGNOSTICKS. CHAr. 4.5 s.
is likely to rain all that day, except the rainbow be seen
before it rains. *x * ,
If the last eighteen days of February and ten days of
March be for the most part rainy, then the spring and
summer quarters will probably be so too: and I never
knew a great drought but it entered in that season.
If the latter end of October and beginning of Novem-
ber be for the most part warm and rainy, then January
and February are likely to be frosty and cold, except
after a very dry summer.
If October and November be snow and frost, then
January and February are likely to be open and mild.
His omnibus ea ingenio suo quisque demat
vel addat fidem.
gº.
*
Char. 5. EFFECTS OF WEATHER, etc. 163
CHAPTER V.
OF THE INFLUENCE OF PECULIARITIES OF
WEATHER ON THE FUNCTIONS OF ORGA-
NISPD BODIES.
It is generally believed that atmospheric
changes have considerable influence on the
state of our health; and such a belief
appears to be founded on reason: for, if
a number of persons, of various ages, of
dissimilar constitutions and habits of life,
and at different places, become the sub-
jects of disorder at the same time, which
appears often to be the case, it is rational
to attribute their malady to Some general
cause then prevailing. And the occur-
rence of disorder in particular kinds of
weather, or at stated seasons of the year,
which some persons experience, naturally
suggests the idea that such cause resides in
the air. * *-
But it appears to me, that it is not
the heat or cold, dampness or drought
of the air, which is chiefly concerned in
I 66 EFFECTS OF WEATHER CHAP, 5.
producing disorders, nor the sudden tran-
sition from one to another of those states;
but that it is some inexplicable peculiarity
in its electric state. The pain felt in limbs
which have been formerly broken, previous
to a change of weather, and the disturbed
state of the stomachs of many persons
before and during thunderstorms, are suffi-
cient, I think, to warrant such a conjec-
ture.
During what has been denominated un-
healthy weather, when medical practitioners
have spoken of the general ill health of
their patients, I have remarked circum-
stances which appeared to denote an irre-
gular distribution of the atmospheric elec-
tricity. The manner of the distribution, and
the continual and multiform changes of the
cirrus cloud, ramifying about and extending
its fibres in every direction; the rapid for-
mation and subsidence of the cirrocumulus
and cirrostratus in different places, and the
irregular appearance of the other modifica-
tions; the intermitted action of De Luc's
aerial electroscope; strong and varying
winds; and the abundance of luminous
meteors by night; are the circumstances to
|
Chap. 5. ON VITAL FUNCTIONs. 167
f
which I allude. A kind of weather too
which appears to be remarkably unwhole-
some is characterised by all the clouds having
confused indefinite edges.”
* In people of what are called nervous and suscep-
tible constitutions, I have frequently noticed a remark-
able variety in the appearance of the hairs on the head:
they have appeared, at times, diminished in quantity:
at others, superabundant. I have examined them care-
fully, in each of their states, and found their apparent
diminution to consist in the shafts themselves becoming
smaller, dryer, losing their tension, and lying in closer
contact. I was once inclined to attribute their closer
contact to a diminution of their electricity, by which
they would become less mutually repulsive: this, how-
ever, does not seem sufficient to account for their de-
crease in size. The shaft may possibly be organized
throughout, and its enlargement may be caused by an
increased, action of its vessels; there may also be an
aëriform perspiration into its cavity, on an increase of
which it may be more distended; and the increased
size and tension of the shaft may result from the co-
operation of these two causes. The increased size,
strength, and tension of the hair, appear to accom-
*. pany health, while the opposite state seems to be con-
nected with disorder. The sympathies between the
skin and the stomach have been frequently adverted to
by physiologists; the skin has been found to be alter-
nately dry and hot, moist and hot, dry and cold, and
moist and cold; and these varieties have been attribu-
ted to varieties in a state of the stomach, between which
and the skin a very direct sympathy is believed to
exist. But the varieties in the appearance of the hair
b63 EFFECTS OF WEATHER CHAP, 5.
But though we admit the influence of
atmospheric peculiarities on our health, yet
the manner and extent of their operation
cannot easily be ascertained. They may
deprive persons, already weak, of a por-
tion of their electricity, and thus the ener-
gies of the brain and nervous system may
be diminished : or the atmospheric electri-
city, being unequally distributed in the air,
do not appear to have been noticed. I have observed,
that small doses of mercury have changed the appear-
ance of the hair very soon after their administration.
From being flaccid, dry, and small, it has become
tense, strong, and moister. Now mercury may increase
an aeriform perspiration into the cavity of the shaft,
if such an one exist; it may also rectify a disordered state
of the digestive organs, and, by that means, cause a
stronger and more healthy action of the vascular system,
and of the vessels of the hair among the rest. I think
it by no means follows that hairs are not vascular, because
we cannot demonstrate their vessels. On this subject,
I think, we may reason thus: if all nourishment be
effected by the action of vessels, it follows, either that
there must be some vessels not nourished at all, or that
vascularity must extend ad infinitum. Can we demon-
strate those small arteries which ramify in the coats of,
and nourish the smallest vasa vasorum ? Such reflections
as these ought to prevent our denying organization to any
part of a living body, even to the cuticle or the enamel
of the teeth.
Chap. 5. ON WITAL FUNCTHONS. H69
or propagated downward at intervals, it
may occasion an irregular distribution of it
in our bodies, and produce an irregularity
of function. A living animal consists, as to
its vital parts, of numerous nerves, which
give life, as it seems, to all the parts, and com-
pose different organs of vitality and mind,
but these must have some mover. We do not
know that this moving principle is electricity;
but it seems reasonable to ascribe it to some-
thing in the air; because, deprived of good air,
we soon die. It would be vain to inquire
into the principle of life; but as air is neces-
sary to its continuance, so bad injures it: so
to some peculiarity in its quality we can rea-
sonably ascribe as many unknown disorders,
even were there not remarkable appearances
in the atmosphere at the time of their preva-
lence. In whatever way the nervous func-
tions may be disturbed, a disordered action
of the digestive organs will be the pro-
bable consequence; and a state of nervous
and digestive disorder being once induced,
other diseases may insue, to which there may
be a constitutional predisposition.*
* This part of the subject has been well illustrated
by Mr. ABERNETHY, in his “ Surgical Observations
170 EFFECTS OF WEATHER CHAP.5.
But it would seem that there were a more
immediate connexion between the peculiar
state of the air, and the kind of disorders
which might be thereby excited, than this.
For it may be observed, that even of those
disorders which are not generally admitted
to be contagious, one particular kind will
prevail for a long time. Thus, in winter,
the different symptoms of that state of body
which we call a cold, appear, in some mea-
sure, to prevail and vary together; so that
it is common to hear people talking of the
fashionable complaint. Coughs, for a while,
are the prevailing symtoms; then sore
throats are the most common. It is in
spring that certain kinds of cutaneous erup-
tions usually appear; and in autumn, that
those irregularities in the functions of the
digestive viscera, called cholera morbus, etc.
happen, besides the many diseases that in
tropical climates accompany particular
winds or weather. It is possible there may
be different states of atmosphere, which act
as specific stimuli, and produce their corres-
ponding peculiar diseased nervous actions,
“ on the constitutional Origin and Treatment of Local
“ Diseases.”—London, 1818.
Char. 5. ON VITAL FUNCTIONS. 171
having as it were a joint cause, and being
further varied by the particular state of con-
stitution, and other circumstances of the
patient. -
Even contagious diseases break out at very
uncertain periods, and often without any
obvious cause, though they are afterwards
evidently propagated by infection. Parts of
Turkey are said to be visited by the plague
every five or six years, while the same dis-
order appears more rarely in other places.
The small pox rages for a time throughout
whole tracts of country; at others, there is
scarcely a case to be met with: the same
may be observed of scarlitina and measles.
I cannot persuade myself that this is merely
the effect of accidental introduction. Is it
possible there may be some quality in the
air, at particular times, whereby it is fitter
for the conveyance of infectious matter? Or,
can we suppose the effect of a peculiar state
of atmosphere to be that of rendering the
body more susceptible of infection than
ordinary. - -
In artificial society there are so many
causes operating to produce ill health, that
the extent of the influence of any one can
172 EFFECTS OF WEATHER CHAP.5.
hardly be ascertained. Inactive habits of life,
bad air, irritating food, the drinking of spi-
rituous and fermented liquors, the misguid-
ance of the appetites, and the reciprocal
operation of the mind and body on each
other, have all a tendency to produce dis-
ease. But though these various evil habits
of artificial life all act to our detriment, their
kind of influence may be somewhat different:
and in proportion as families, and even
nations,” may have indulged, from time to
* In the production of national varieties, local situa-
tion is probably much concerned; and, in this case, the
influence of the atmosphere, in their production, does
not seem to depend on the degree of heat alone: for
not only the colour of the skin and hair, but the form
and countenance, and also the diseases of different nations,
inhabiting nearly the same latitude, vary considerably.
The varieties of the soil and its vegetable productions,
which constitute part of their food, may have a degree
of influence; and so may peculiarities in the electric
state of the air in different longitudes: but there are
hordes of savages inhabiting the same tract of country,
and living in near neighbourhood, which differ much
from each other. And we may add, that among people
of the same nation there are scarcely two heads and
consequently no two minds exactly alike. It is remark-
able, that this variety of figure, of expression of coun-
tenance, and apparantly of kind of mind, is increased
in proportion as man beeomes civilized. The number
CHAP.5. ON VITAL FUNCTIONS. 173
time, in any of them, they may have ac-
quired what are called constitutional pecu-
and variety of his diseases are also multiplied by civili-
zation. The effect of civilization in producing variety
and disease, is also observable in those animals which
have been domesticated. In proportion as they have
approached the habitations of man, and lived under his
roof and protection, their natural habits have become
altered and perverted, the size and figure of their bodies
changed and various; and they have, like man, to whom
they owe their deformity, become the subjects of number-
less diseases. I have dissected many domestic animals,
and have often found in them extensive ossifications of
soft parts, and preternatural tumours: but I never
recollect to have found any marks of organic disease in
those which may be truly called wild.
Human nature, from the influence of various causes,
having been infinitely varied, and constitutional varieties
being in some measure transcendant, every one is pro-
bably born with some peculiarity, and, perhaps, more
or less, with some particular tendency to disease. Pecu-
liarities of character being afterwards modified and di-
versified by education, the varieties become almost infi-
nite. The subject of variety leads me to the following
considerations. Of all the animated and vegetable
beings which inhabit the earth, no two species are alike,
each has its peculiarities. From the concretions of the
earth itself, up to man, there appears to be a succession,
to use common language, of more and more perfect
beings. From saxeous excrescences we ascend to lichens,
and, through all the infinitely various tribes of vegetables,
to the polypus and star fish, connecting as it would seem,
1
174 EFFECTS OF WEATHER CHAP. 5.
liarities or temperaments; and the diseases
dependent on them may be infinitely varied
by the subsequent combination of different
evil habits in individuals. For example,
sedentary occupations have been considered
to hurt our health, by causing an accumula-
tion, or irregular direction, of the nervous
energy, which ought naturally to be spent
on the various muscles. T hus patients, suf-
fering great and peculiar nervous irritation,
have been relieved by a degree of exercise,
which, in common cases, would have caused
lassitude. The different kinds of spirituous
vegetable and animal life together. From these every
link in the chain appears filled up by numberless ani-
mals possessing intellect in different degrees, and having
infinite peculiarities, till we arrive at man. And in man
what infinite variety of organization in different indi-
viduals both in kind and degree, from the most complete
ideot, whose abject imbecility brings him below the level
-of a brute, to the most elevated and intellectual cha-
racter. In ascending the scale of mind, and tracing vari-
ety through all its branches, whether we consider that
difference which merely arises from the comparative de-
velopement of different organs, or that which is pro-
duced by all the numberless disorders of body, or by
mental insanity, do we ever observe two alike?—All
nature is chequered with endless variety of forms, which
appear from time to time and are lost for ever, while
mutability goes on producing ceaseless combinations.
CHAP, 5. ON VITAL FUNCTIONS. 175
and fermented liquors are, probably, perni-
cious, by affording a stimulus exhausting to
the strength; but whether they prove uni-
formly injurious in proportion to the quan-
tity of pure spirit which they severally con-
tain, or whether the different kinds of spiri-
tuous drinks cause different specific actions,
is a point which, I think, has never been
determined. Doctor Lambe considers ani-
mal food and impure water as exhausting
stimuli; but he seems to think their re-
spective actions on the system as some-
what different. If they do actually contain
deleterious substances, the doctrine about
which however seems very vague and incon-
clusive, their evil influence may be increased,
in certain states of disease, by the lacteals
losing their discriminating power, and, like
common absorbents, drinking up unassimi-
lated or noxious matter, in consequence of a
disordered state of the chylopoietic system.
In these cases, then, attention to regimen
must be particularly necessary. Such a view
of the subject as this enables us, in some
measure, to reconcile the beneficial effects
of vegetable diet on many persons, with the
apparent health of others who live chiefly
176 IEFFECTS OF WEATHER CHAæ, §.
on flesh. To return from the digression into
which I have unavoidably been led : those
persons are most likely to be disordered by
atmospheric peculiarities, who have the
greatest susceptibility of constitution, and, at
the same time, the greatest weakness.*
* It appears, that an unhealthy quality in the air,
which was believed to excite disorder, was frequently
alluded to by amcient writers. So Lucretius—
Nunc ratio quae sit morbis, aut unde repente
Mortiferam possit cladem conflare coorta ;
Morbida vis hominum generi, pecudumque catervis,
Expediam. Primum multarum semina rerum
Esse supra docui, quae sint vitalia nobis;
Et contra quae sint morbo mortique, necesse est
Multa volare; ea quom casu sunt forte coorta
Et perturbarunt coelum, fit morbidus aër.
Atque ea vis omnis morborum, pestilitasque
Aut extrinsecus ut nubes nubulaeque superne
Per coelum veniunt, aut ipsa saepe coorta
De terra surgunt ubi putrorem humida nacta est
Intempestivis pluviis, et solibus icta. •
Lucret. de Rer. Nat. lib. vi. 1089.
Again—
Est elephas morbus qui propter flumina Nili
Gignitur Aegypto in media, neque praeterea usquam.
Atthide tentantur gressus oculique in Achaeis
Pinibus: inde aliis alius locus est inimicus
Partibus ac membris; varius concinnat id aër.
De Rer, Nat. lil. vi, 1112,
Char. 5.51. ON VITAL FUNCTIONS. 177
SECTION I.
Further Observations on the Effects of Atmo.
spheric Peculiarities on the Functions of Or-
ganized Bodies.
EveRY organized body, as far as human
sagacity can penetrate, appears susceptible
of diseased actions, which may be excited
by different causes. In man these causes
are various and complicated, and the mor-
bid actions which arise, in consequence, are
numerous and dissimilar. And this circum-
stance may be attributed to his organization
and to his mode of life. The influence of
the atmosphere, which is one cause, is apt
to be overlooked in the human subject, from
the variety of others which are continually
Which Virgil has imitated—
Hic quondam morbo coeli miseranda coorta est
Tempestas, totoque Autumni incanduit aestu.
Etgenus omneneci pecudum dedit, omneferarum,
Conripuitgue lacus; infecit pabula tabo. *** -
Virg. Georg. lil. iii. 478.
N
178 EFFECTs of WEATHER CHAP.5.51.
*A
operating, and which, though by their con-
joint influence, they predispose to, and often
aggravate its effects, have nevertheless a
tendency to mislead our judgment as to the
manner and extent of its operation. k
Animals, particularly those which are do-
mesticated, on which alone we can make
any accurate observations, have many
sources of disorder, though not so many
as man has. They may suffer from hunger,
from unnatural food, from fatigue, or from
accidental injury, which may produce dis-
ease, and which may be the cause of their
becoming affected by peculiarities in the air:
notwithstanding their comparative freedom
from the evils of intoxication, gluttony, and
mental perturbation, that prove so frequently
destructive to the human subject. The
almost simultaneous occurrence of canine
hydrophobia in distant parts of the country
must be ascribed partly to some peculiarity
in the atmosphere; while the circumstance
of its occurring primarily only in a few
dogs, would lead us to consider some pre-
existing, and, perhaps, unnoticed state of
disorder in the animal, as conducive to the
case.º.º. on vitaL FUNCTIONS. #79
more wiolent affection subsequently excited
by the air.” There are many other instances
of record of epidemic distempers among
animals, which have prevailed only for a
time, and which seem to be referrible to the
atmosphere. A few years ago, in Essex, a
mortality prevailed among cats, which car-
ried off considerable numbers. The mange
is said to be contagious; but, if this be the
case, it is one of those disorders which arises
from unknown causes in a great many ani-
mals at once, and may be afterwards propa-
gated by contagion. The same mode of
reasoning seems applicable to the glanders
of horses, and to many other distempers of
eattle.
How far electricity may be concerned in
all this, it is difficult at present to say; but
* Virgil aptly alludes to the influence of unhealthy air
on animals, though not subject to the general causes of
human diseases, namely, wine, gluttony, and mental
anxiety.
Atqui non Massica Bacchi
Munera non illis epulae nocuere repostae,
‘Frondibus et victu pascuntur simplicis herbae
Pocula sunt fontes liquidi atque exercita cursu
*Flumina, mec somnos abrumpit cura salubres.
Pirg, Georg. lib. iii. 530.
N 2
180 EFFECTS OF WEATHER CHAP.5. $2.
the discoveries which philosophers are daily
making, relative to the extensive operation
of this fluid, (for such I must call it, till a
better name be found,) seem to encourage
a suspicion, that its agency is concerned in
producing every change in the universe.
SECTION II.
Of the Effects produced by Peculiarities of
Atmosphere on Vegetables.
Not only the animal, but also the vege-
table kingdom, appears to be affected by
peculiarities of the atmosphere, which do
not consist in its degree of temperature or
pressure. For example, in the summer of
1810, almost all the plane trees, with the
rough bark or rind,” became diseased in the
neighbourhood of London, and for many
miles round; very few of which, in compa-
rison with the whole number decayed, reco-
vered so far as to throw forth buds the
ensuing spring, while the smooth rined
plane trees t and sycamore trees j remained
-
* Platanus Occidentalis. # Platanus Orientalis.
f Acer Pseudoplatanus.
Char. 5. 32. ON VITAL FUNCTIONS. 1st
healthy. The season was not either remark-
ably hot nor very unusually dry; but there
were all those circumstances alluded to in a
preceding section as demonstrating an unu-
sual state of the atmospheric electricity.
The succeeding summer, that is, in 1811,
some of the same species of plane trees were
again deceased, and a few died. I am in-
formed, that some years ago a similar,
though not so extensive a mortality, pre-
vailed among the smooth rined plane trees.
From hence it would appear, that there
were particular states of atmosphere which
become specific stimuli to diseased actions of
particular plants. Abundant proof of the
fact, that particular seasons destroy particu-
lar tribes of vegetables, may be collected
from gardeners and nurserymen. There are
many other facts, which it would be useless
to detail, that illustrate the proposition, that
there are other peculiarities of atmosphere,
besides heat, cold, damp, &c. which affect
the functions of organized bodies.*
* It cannot, I think, be considered, that atmospheric
peculiarities alone produce epidemic and other com-
plaints, which must be regarded as having a compound
origin, and as resulting from the operation of peculiar
{
*
182 EFFECTS OF WEATHER. CHAP. 5. $2.
states of atmosphere on persons of particular states of
constitution; otherwise, all persons would be affected,
which is contrary to experience. There are, probably,
innumerable varieties of temperament, of general habits of
life, and of preexisting diseases, which, in different sub-
jects, vary the effects of the air. And many persons,
perhaps, enjoy a state of health, and perfect action, which
may be capable of resisting its evil influence altogether.
It would, perhaps, be productive of useful results, if phy-
sicians of extensive practice would make accurate meteo-
rological registers, during the prevalence of any epidemic
or contagious disorders: such as the influenza, which, a
few years ago, took a range for some miles round Lon-
don, but was also prevalent in other parts of the country.
Since writing the above, I have met with some curious
observations on the influence of climates, (which corre-
spond, in some measure, with what I have advanced,) in
a French work entitled Rapports du Physique et du Moral
de l'Homme, par P. J. G. Calanis, 2d edit. Paris, 1805,
Gwar, 6. ()R WINP)& 1,83.
- . (THAPTER VI.
S9ME PARTICULARS CONCERNING WINDS.
WIND has been explained in the following
manner. Heated air has a tendency to rise,
and cold air rushes in to supply its place.
Thus the heated air of the equatorial regions.
rises, and gives place to a current from the
polar regions, which is a process that serves.
to equalize the temperature of the world.
But the polar countries lying nearer to the
axis of the sphere, the air from those regions
has not received so much motion as that
about the equator, or greatest distance from
the axis; wherefore it arrives at the equator,
where the motion of the earth is greater.
If it had no motion before, an East wind
would be the consequence, and the force of
that wind would be as the difference be-
tween the motion of the earth where the air
came from, and that where it arrived: but
then it has a motion to the South; for it is
rushing into a vacuum, left by the air which
18, OF WINDS. CHAP. 6.
rises: so that the wind will not be from East,
but North East; and the number of degrees
North of the East from which it will blow
will depend upon the comparative force of
the current of air from the North to the dif-
ference between the earth's motion at the
equator and at the polar region, from whence
the air comes. As there must be a corre-
sponding efflux from the equator higher up;
according to this theory, the wind should
every where be North East or South West;
but it blows in very different directions at
different times and places; and this probably
depends on the variations in temperature at
different times and places. I shall not enter
into the detail of the subject, but refer to
several treatises written on winds by different
authors.”
I have lately remarked a circumstance
with regard to the change of winds, which
I have never heard mentioned by meteoro-
* Since the publication of the first edition of this work,
I have made many experiments with balloons, and have
observed them always to move in two or more currents,
whenever the wind was not so great as to carry them soon
away from sight.
CHAP. 6. of winDs. 185
logists, and which may therefore be worth
noticing. I have observed, that when the
current next the earth has changed its direc-
tion, it has frequently got into a quarter from
which an upper current had previously blown.
I was first apprized of this, by observing the
motion of an upper stratum of clouds to be
different from that of those which were
lower; and by the lower clouds afterwards.
taking the direction of those above: but
as I had few opportunities of observing
this circumstance, I thought it merely acci-
dental. Subsequent observations on the
various directions of air balloons, and the
succeeding changes of the wind, have con-
vinced me that it is frequently the case, that
the changes of the winds begin above, and
are propagated downwards. And I have
observed this of several successive currents.
For a detail of some of my experiments
made to ascertain this circumstance, I refer
the reader to the Appendix to this volume.
186 OF ELECTRIGHTY. CHAP, 7.
CHAPTER WIF.
OF ELECTRICITY.
If we look back into the history of any
branch of science, we shall observe, that
in the progress of its developement, men
have, from time to time, introduced a num-
ber of different hypotheses to explain the
causes of the complicated phaenomena which
they observed; which hypotheses have ob-
tained credit for a while, and have reigned
triumphant; but before long they have
faded away, from being found incapable of
explaining more recently discovered facts,
or have been overthrown by others of greater
pretensions to credit. From time immemo-
rial, systems of philosophy have mutually
overthrown and succeeded each other ; and
many, which have been rejected by philoso-
phers of antiquity, have been brought into
vogue again, under some new dress, by sub-
sequent generations; and thus, in the revo-
lutions of Science, systems have alternately
decayed and flourished at remote distances
CHAP. 7. OF ELECTRICITY. 18?.
of time. Electricity affords a striking exam-
ple of this. After the two different electric
states of bodies, commonly called the posi-
tive and the negative charge, were discovered
by certain dissimilarity in their effects,” phi-
losophers began to dispute about the state
of those bodies. Some contending that
when two different electrics were rubbed
together, so as to become electrified, the
one gained as much as the other lost of a
fluid matter, which they called the electric
fluid; and that when, by Subsequent ap-
proximation, or the intervention of conduc-
tors, their electric properties ceased, an
equilibrium of the fluid in the two bodies was
again restored. While others contended for
two distinct fluids, which had a sort of at-
traction for each other. Upon this supposition,
the electrification of two different bodies by
friction was a separation of the two fluids, one
to eachelectric, and the equalization was a com-
mixture again, or a distribution of both elec-
tricities through both the electrics. Many
* For example, the difference of appearance of the
luminous star on the point of a conductor, when applied
to a body positively charged, from that of the star on
the point directed to one negatively charged.
188 OF ELECTRICITY. CHAP, 7.
plausible experiments and arguments were
used in favour of each hypothesis: but the
former always obtained the most credit.
While electricians were thus contending, the
ingenious I. A. De Luc proposed a system
somewhat different from either of the
former, an account of which may be found
in his works, to which I refer the reader,
and leave him to judge of the validity of
it by the evidence there adduced. While
some philosophers have contended for one
fluid, and some for two, others have re-
cently contended for no fluid at all, and
have spoken of electrical effects as depending
on the agencies of matter. Without dwell-
ing on these adverse systems, which appear,
in a great measure, verbal differences, I shall
merely observe, that there are certain modes
of action of bodies on each other, such as
all the phaenomena of artificial electricity,
etc. which custom has ascribed to the agency
of a specific fluid. Whatever may be the
principle of their action, the daily expe-
rience of philosophers shows the extent of
this principle. Indeed, recent discoveries
and experiments incline one to regard it as
the universal agent in all the changes of
CHAP. 7. OF ELECTRICITY. 189
form which matter undergoes.* A notion
of the antiquity of which, though it be now
newly revived as a subject of philosophical
speculation, there appears some traces of in
the accounts left of the religion of Zoroaster,
or the worship of the spirit of fire, as the
soul of the universe, the source of all mo-
tion and of life.
In attributing the forms of clouds, the
production of rain, and other atmospheric
phaenomena, to electricity, I would not be
understood to involve any particular theory
of the mode of electrical action. It is
merely intended to ascribe similar appear-
ances to similar causes, and to extend the
principle of action upon which the phae-
nomena of artificial electricity are explained,
which has been identified with that of light-
ning, to other atmospheric productions,
which, at first sight, are less obviously refer-
rible to similar agencies.
I have already, in treating of Mr.
Howard's theory of the modifications,
shown how reconcileable that theory was
.* The discoveries made by Sir H. Davy seem calcu-
lated to throw light on this interesting subject.
:#50 OF ELECTRICITY. CHAP. 7: §1.
to the various phaenomena exhibited by
the clouds. There are many things, how-
ever, which I have not sufficiently explained
there, which may be mentioned in this place.
SECTION I.
Of the Electric State of the Modifications of
Clouds.
IT is necessary to the present hypothesis,
and is indeed conformable to constant
experience, to consider lightning, at least
one kind of it, to be the discharge of the
electric spark; and yet, at first view, the
reconciling the electric charge of the
nimbus, which would be necessary to the
effect, with its being the result of the union
of two dissimilarly electrified clouds, and
consequent neutralization of the two elec-
tricities, seems to involve a contradiction.
To explain this, I must observe, that after
two differently electrified clouds, whose
structure and buoyance depended on the
similar electric charge of their particles
severally, by a communication, and the in-
Char, 7.91. of ºf RfCity. #131
tense ſunion of the said particles, should
form the dense structure of the nimbus,
the latter cloud, when fortried, may acquire
a strong charge, for it would be thrown into
*ah opposite state to that of the earth, or
other objects over which it might pass, or
to other clouds in vicinity; for its acquiring
again a charge would not cause it to reas-
‘surheº the primitive structure of the clouds
of which it was formed, for it now was
‘condensed to minute drops of water, a state
‘probably very different from that of any
other modification. Under these circum-
'stances, then, the nimbus may exist as a
‘highly electrified conductor: and it is pro-
bable that the difference between common
'showers and thunderstorms consists in the
intensity of the charge which the nimbus
acquires after its formation.
ft must be granted, that though the pre-
sent theory seems so well to agree with the
fortnation of nimbi, it is nevertheless insuffi-
cient to account for all the differences of
the other modifications. We may readily
conceive the fibrous structure, and other
circumstances of the cirrus, to be the effect
of its office as a conducting body, effecting
192 OF ELECTRICITY. CHAP. 7. § 1.
an electric communication; but we can
assign no reason why a strong positive
charge should produce a cirrocumulus, in-
stead of a collected mass like the cumulus,
nor under what dissimilar circumstances
electricity should cause the infinite variety
of forms under which that cloud, or the
cirrus or cirrostratus, appear on different
occasions. It has been conjectured, that
the plane cirrostratus is often placed be-
tween two differently electrified plates of
air, between which it may be effecting a
slow communication; and that the alter-
nate bars of this cloud, at other times, may
be interposed between portions of air alter-
nately electrified with plus and minus.
Experiments are wanting to ascertain these
facts; but, could they be demonstrated,
such an alternate distribution of the elec-
tricity of the air would remain unaccounted
for. If the conjecture be true, the streaks
of cirrostratus may serve an office analogous
to that of the water interposed between
the plates of zinc and copper in the voltaic
apparatus: and it is a fact, in some measure
conformable to this idea, that the cirrostra-
tus, after losing its wavy or its striated ap-
1
Chap.7.51. OF ELECTRICITY. 19%
pearances, has been observed to condense
into a nimbus, and produce rain without
the help of any other cloud, as if it contain-
ed within itself the principles of its own
resolution into water. The oblique and
curved columns of this cloud seem, indeed,
hardly explainable even on this supposition.
The curious cymoid feature, which so
often precedes storms, is not merely al-
ternate bars, but the bars are curiously cury-
ed; a circumstance still more difficult
of explanation. Future and repeated ob-
servations may, possibly, in the course of
time, throw more light on these varieties.
To return to the cirrocumulus: if it be
a cloud with a strong charge, and very re-
tentive of it, the latter circumstance, pro-
bably, results from its being surrounded by
dry air, which is not a conductor. Con-
formably to this view, I have noticed the
loose indefinite features, which accompany
damp air, and appear, in the intervals of
COIII II, Oſl showers, to be of short duration:
and that they have passed to a sort of con-
fused cirrus or cirrostratus, while the dense
and compact aggregates, which compose
the stormy features, are often of long dura-
O
1$4. Of ELECTRICITY. Char. 7, § 8,
tion; and I have not observed this dense
feature to form itself into cirrus and cirros-
tratus in the manner afore described. The
densest nimbi, and the hardest thunder-
storms, often follow its conjunction with
cumulus and cumulostratus. Another dis-
tinction is also worthy of remark. The
loose, flimsy, and transient features of cir-
rocumulus, often appear above, when cumuli
are rapidly flying along in the gale below;
whereas the denser feature more often ac-
companies a calmer air, particularly the dead
calm which precedes a storm on a sultry
summer's afternoon. There are other kinds
of cirrocumulus, as I have already men-
tioned, which attend fine warm weather,
which are large distinct and well defined ag-
gregates arranged all over the welkin. To me
it is somewhat doubtful what particular kind
of cloud Virgil,” Lucretius, f and Pliny, i.
* Temuia mec lanae per coelum vellera ferri.
* Wirg. Geor.
I must refer the reader to my edition of the Diosemeia
of Aratus.
# Conciplunt etiam multum quoque saepe marinum
Humorem, velutipendentia vellera lanae
Quum supera magnum wentimare nubila portant.
Iucret. vi. 504.
it Plin. Hist. Nat. xviii. 35.
CHAP. 7.62. OF ELECTRICITY. 193
alluded to as being like fleeces of wool, and
which accompanied rainy weather. The
descriptions of them by the Roman poets
seem to have been imitated from Aratus,
in his Diosemeia, who represents them as
signs of rain.” *
# SECTION II.
Of the Electricity of Thunder Clouds ; and of
Lightning.
It has appeared by some experiments,
that a thunder cloud exercises its electrical
influence on the surrounding air, and throws
it into an opposite state: so that if the
cloud be positively electrified, there is a
portion of air negatively electrified around
it; and, beyond that, a positively electri-
fied portion perhaps again. But a suffi-
cient number of experiments have not as
yet been made, with electrometers, to cer-
tify whether this be the case with all
* IIoxxox 3’ exopºvoy vetøy wipeg wborápolºgy,
Ois gºuro. Tánaigly ion:éra w83xxoſal.
Arat. Dios. 207.
o 2
196 of ELECTRICITY. Chap.7. $2.
clouds. It is probable most of the flashes of
lightning never reach the ground, but are
only communications between the thunder
cloud and some other, either oppositely, or
not at all electrified.
The hypothesis of Van Mons, that the
two different kinds of thunder and light-
ning are the result of very dissimilar causes,
and that one is the combustion of the gasses
of water, seems wanting in proof. The
reports are certainly different; and mischie-
vous effects generally happen with that
kind of which the report is single, or of very
short duration, and which happens soon after
the flash. But these circumstances may be
attributed to the nearness of the cloud to the
object destroyed by the lightning. There are,
however, differences in the appearance of
lightning: it looks at some times much bright-
er, and of a bluer light, than at others.
This difference of colour is most remarkable
in the vespertine fulgurations in Summer;
which form the subject of the next section.
I cannot omit to mention one circum-
stance, which seems rather contrary to my
explanation of the differences of claps of
4
CHAP. 7. § 3. OF ELECTRICITY. 197
thunder, and rather favours the hypothesis
of M. Van Mons, namely, that the two
kinds of thunder often happen, and, indeed,
alternate with each other in the same storm.
The meteors or balls of fire which occa-
sionally shoot from thunder clouds during
a tempest are very curious; they seem to
show, if they be electrical, which is most pro-
bable, that similar causes to those which pro-
duce thunder and lightning may also produce
the electrical fire embodied in the form of
meteors. A curious experiment to show
the embodied form of the electric fluid was
made in France by MM. Arden and Consta-
ble. Refer to Bertholon Elec. Met. vol. ii. p.
27.
SECTION III,
Of Silent Lightning.
THE silent lightning of warm summer
evenings seems sometimes to come from
visible clouds; but, at others, flashes of great
latitude appear almost all around the horizon,
when no cloud can be seen. These are
398 OF ELECTRICITY. CHAP. 7. § 3.
either the effect of clouds too distant to be
observed, or they may be communications
between the damp earth and the hazy air
above. The most remarkable thing, is their
always being seen in the horizon. When
there be definite clouds about, then are
the flashes the brighest; a circumstance
which looks as if the flashes which appear
without clouds were only at too great a
distance for the clouds from which the flashes
come to be seen. In either case the com-
munication may often be with the ground,
which, in the damp of the evening, with
falling dew, would not be violent, as the
general moisture would afford a more free
and latent, and, consequently, a more gentle
passage to or from the earth.* Upon this
principle, we may see also why nocturnal
storms are generally less mischievous than
those which happen in the day time, and
why there is additional security in thunder-
storms after the rain has commenced.
* The Abbé Bertholon thought he could determine
when the Hightning rose from the ground to the cloud,
and when it descended from the cloud to the ground,
Bertholon, Elec. Met, vol. i. c. iv. p. 132. He refers to a
letter of Maffei, Della Formazione del Fulmine, in the Jour-
mal de Venice, Tom. xxxii. art. 7.
6
chap. 7. $4. OF ELECTRICITY. 193
SECTION IV.
Of the Aurora Borealis.”
AFTER the attention of philosophers began
to be directed to the atmospheric electricity,
the Aurora Borealis and Australis, com-
monly called the Northern Lights, were con-
sidered as electrical. There appear, how-
ever, to have been several different explana-
tions of this phaenomenon.
Franklin regarded the coruscations of nor-
thern lights as the result of a slow and con-
tinual discharge of electric fluid from the
atmosphere about the poles to the air above;
and Sir H. Davy, and also many other elec-
tricians, have noticed the striking similarity
between those lights, and electricity dis-
charged through rare air. †—The reason why
these Auroras only happen towards the poles,
has been said to be, because in high latitudes
alone there can be a continual coating of
ice and snow, to prevent the electric com-
* Aurora Polaris would be a better name; as it is not
confined to the Septentrional regions.
+ Refer to Davy. Elem. Chem. Philos. vol. i. p. 141.
300 OF ELECTRICITY. CHAP. 7. $4.
munication taking place between the earth
and the atmosphere above. The Aurora
has also been explained by supposition that
the earth may have electric polarity; and
the correspondence between the centre of
the Aurora and the magnetic poles, which
has been asserted, is a circumstance very
worthy of future consideration, as it tends to
establish more certainly the connexion be-
tween electricity and magnetism.* .
* Mairan, in his Traité Physique et Historique de PAu-
rore Boreale, 4to. Par. 1754; observes that it resembles
what is called the zodiacal light; and supposes that they
are both emanations from the sun. In the work above
alluded to, many curious accounts and figures of the Au-
rora, may be found. For further accounts, consult Phil.
Trans. Also Bertholon Elec. Met. vol. ii. p. 49.
Since the publication of the first edition of this book,
the phaenomenon of the Aurora Borealis has again at-
tracted the notice of meteorologists in this country; but
they have neither been so grand,’ nor so frequent as for-
merly,
CHAP. 7. § 5. OF ELECTRICITY. $29%
SECTION V.
Of several other Electrical Phaenomona.
To the above described electrical phaeno-
mena may be added several other dissimilar
appearances, referrible to the same principle,
operating under different circumstances.
Water spouts probably result from the at-
traction of a nimbus for the water over
which it may be, whence both are violently
drawn towards each other, till they meet: *
and when the electricity of the cloud has
been equalized with that of the water, the
column comes down. Though this effect is,
to a certain degree, explainable on this sup-
position; yet, as, in other instances, the
particular circumstances under which this
rare phaenomenon takes place, are as yet
obscure.
Cavallo attributed the fiery meteors de-
scribed in another place to electricity. As I
* A friend of mine calls this contact of the waters from
below with those from above, Neptune shaking hands
with Jove.
302. OF ELECTRICITY. CHAP. 7. § 5.
have already spoken of these phaenomena;
it is unnecessary to add much more. I only
observe, that there is this difference between
meteors and electric communications, that
the former occupy some time in their pas-
sage, whereas electric communications are
instantaneous; that is, they take place in
no perceivable time.*
The variety too in the colour of the light
of meteors, their scintillations, and the pris-
matic colours sometimes observed in the
tails of the larger sort, are circumstances
which do not appear to me analogous to any
known electrical phaenomena.
Dr. Blagden, in the Phil. Trans.# ob-
serves, in proof of the number of blue rays
which entered into the composition of the
light of the great meteor of 1783, that the
moon appeared at Brussels quite red, during
* There is this difference in the motion of the bril-
liant and larger kind of falling stars or meteors, and
the other two kinds, which I have ealled the stellar and
the caudate. The brilliant meteors of summer evenings
have sometimes a curvilinear motion; whereas the other
two sorts always move nearly straight: though as far as I
can observe, with different inclinations to the horizon,
on different occasions.
+ Phil Trans, lxxiv. 208.
CHAP. 7. § 5. OF ELECTRICITY. 203
the meteor's passage, from the contrast of
light* I have noticed this reddish appear-
ance of the moon during the combustion of
many substances which burn blue, in pyro-
technical exhibitions. In the tail, and in the
Separated scintillations of the aforesaid great
meteor, prismatic colours were observed
very variously, by persons in different places.
These appearances seem certainly to favour
the hypothesis of M. De Luc, as I have before
observed, rather than any mode of explain-
ing them on the known laws of electri-
city. During thunderstorms however me-
teors occasionally come down like balls of
fire which sometimes seem very like those
described above.
There are several dissimilar appearances,
* Dr. B. refers to a letter of Abbé Mann to Sir
Joseph Banks.
+ Some have considered shooting stars as bodies
projected from the moon, and ignited in their course.
In this case, the peculiarities of their light, at different
times, might be caused either by the quality of the air
in which they burned or by the quality of the ignited
body. Meteorolites too have been considered as simi-
larly projected from the moon, and have thence received
the appellation of Lunar Stones. And this opinion has
gained support by their analysis, which does not corres-
pond with that of any known terrestrial compound.
204 OF ELECTRICITY. CHAP. 7. $5.
which may be mentioned in this place, as
Biot, in his Astronomie Physique, and La Place, in his
Sys, du Monde, seem rather of this opinion. The ,
altitude of what are called falling stars, above the earth's
surface, has never been well ascertained, though it might
easily be done by geometrical observation; at least, in
many cases, where the meteor could be identified, as
seen in different places. They are not seen below clouds;
and, indeed, none, except the larger and brilliant kind,
are usually observed when there are many clouds about:
but this may arise from the state of the atmosphere neces-
sary to their production being incompatible with the
existence of much cloud. M. De Luc mentioned to me
his having scen them from the top of high mountains,
and that they then appeared at a very great distance.
From observations which I have made, they certainly
vary in the height, as well as the kength, of their course. It
is not impossible, but that if meteorolites were observed
to fall at night, they might be always ſound to be accom-
panied by some fiery phaenomenon of this kind. The
almost horizontal motion of some large meteors, would
be no objection to this hypothesis, if they always moved.
from E. to W. or nearly so; as, when they came into
the sphere of the earth's attraction, their motion might
he spent, and they would then receive an apparent mo-
tion compounded of the opposite of the earth's rotatory
motion, and the attraction to the centre. An analysis
of several meteoric stones may be found in Sowerby's
Brit. Mineral. vol. ii. p. 18. A catalogue of many of
them, and of the places where they fell, was made and
published in France; there are also many accounts of
them in several numbers of the Philosophical Magazine,
CHAP. 7. $6. OF ELECTRICITY. %3
subjects worthy of the future investigation
of natural philosophers, which seem refer-
rible to electricity: and which appear to hold
a middle nature between the igneous meteors
above described, and known electrical phae-
nomena. There are, occasionally, station-
ary meteors, simple accensions, which ap-
pear in cloudy skies, and last scarcely a
moment. There are also luminous portions
of clouds occasionally, of less intensity of
light, which are faint and glimmering, like
luminous nebulae: and others, which have
a rapid motion, that may be said to have
the same relation to moving meteors above,
which the pale light about plants, before
noticed, bears to the well known phaeno-
menon which occurs below called the Ignis.
Fatuus, Jack with a Lantern, or Will with a
Wisp.
SECTION VI.
Of the Electricity of the Air.
WHAT has hitherto been said of the elec-
tricity of the atmosphere, related chiefly to
30á OF ELECTRICITY. CHAP. 7. § 6.
that of clouds. In serene weather, however,
and in the absence of all clouds, the air has
shown signs of being electrified, by means
of kites raised in the air, and other electro-
meters.” That air should, at different times
and places, have positive and negative char-
ges, is not at all Surprising; but the circum-
stances under which such charges have
taken place do not appear to have been
sufficiently attended to,
During very clear weather, the air
has generally been found to have a
positive electricity, and the exceptions
to this rule have generally happened
when either a strong wind has blown, or
when there have been clouds in the vicinity
of the electrometer. That large electrified
clouds throw the surrounding air into an
opposite state, has already been stated;
and some circumstances have induced an
opinion, that there are alternate portions of
air with different electricities round the
electrified clouds. And it becomes a ques-
tion for future solution, whether, when air
is found electrified positively, there is not
* See Becaria Elec.; also Cavallo Comp. Treat. Elec.
Letters of Abbe Nollet, in Phil. Trans, etc,
CHAP. 7, $6. OF ELECTRICITY.. 207
a counter charge somewhere else? Possibly
the whole atmosphere, and the earth too,
may have electric polarity. That the elec-
tric state of the atmosphere varies much at
different times, is beyond a question, from
the facts above stated; but the causes of its
irregularities, which, in fact, involves the
causes of clouds, etc. is as yet a mystery.
There have been found alternations in the
electric state of the atmosphere, that is,
rapid changes from a positive to a negative
state, and vice versa. These circumstances
were observed near the Appennines, when
a strong wind blew, and when clouds hung
about the tops of those mountains, describ-
ed as having rectilinear spouts at the top,
and which, from the description, I take to
be a kind of cirrus.* Other clouds appeared
at the time, which, by the account, appear
to have been dense cumulostrati and cumuli.
As irregularities in the electric state of the
* Clouds of this kind, attaching themselves to the
tops of high hills and mountains are noticed by Saussure
as being called les nuages parasites; and considered as
portending rain. Refer to Saussure, Voyage dans les
Alpes, § 2070, and M. Du Carla in Journal de Physique
for 1784. Homer. Iliad. v. 522. Theophrastus, De Sign.
Temp., and Aratus, Dios. 188. * *.
208 . OF ELECTRICITY. Chap. 7. 57.
air may be concerned in the production of
many disorders of health, the investigation
of them becomes additionally interesting.
It is much to be wished, that those who
have opportunities of making experiments
with electrical kites, &c. would attend to
what is the general disposition of the clouds,
which prevail during different states of the
atmospheric electricity. An instrument
likely to throw some light on this subject
has been invented by M. De Luc, described
in the next section.
SECTION VII.
€f M. De Luc's Aërial Electroscope, and the
Connevion observed between its Action and
other Atmospheric Phaenomena.”
It may not be improper to present the
reader with a short account of M. de Luc's
Electric Column, or Aërial Electroscope, as
this instrument has been frequently alluded
to in my Journals. º
* See Letters of M. De Luc on this column in many
numbers of Phil. Journal, and in Phil. Mag. the present
month, Oct. 1814, p. 248.
CHAP. 7. $ 7. OF ELECTRICITY. 209
It is composed of a great number of small
circular and very thin plates, about the dia-
meter of a sixpenny piece of silver, of paper
and of zinc, alternately arranged, forming a
column; the two ends of which are made
to approximate, and at each of them is
attached a small bell; a metallic clapper is
then hung between them, and the whole
apparatus is insulated by being fixed on glass
stands. One end of the column is observed
to become electrified plus, as it is termed,
and the other minus; consequently, one of
the bells becomes electrified plus, or positive,
and the other minus or negative: and the
metallic clapper moving rapidly from one to
the other, to equalize the two electricities,
a pulsation is produced, and the bells ring.
Neither the heat or cold, dryness or moisture
of the atmosphere, appear to have any con-
siderable influence on the action of this in-
strument; but it is considerably altered by
peculiarities in the electric state of the
atmosphere. The prevalence of cirri rathi-
fying about the sky in various directions, and,
accompanied often by other modifications,
by dry easterly and changeable winds, aſid
by numerous small meteors of an evening
P
210 OF ELECTRICITY. CHAP. 7. § 7.
which appear to indicate a disturbance in the
atmospherical electricity, I have noticed to
be accompanied by an irregular action of the
Electric Column of M. De Luc; the bells
ring at intervals, and with a kind of hurried
pulsation. When such weather as I have
described is followed by rain, the bells
have been found silent. There are also
other varieties in the kind of pulsation
of the bells; sometimes they ring weak
and regular, sometimes weak and irregular,
sometimes strong and regular, at others
strong but irregular; the intervals of quies-
cence are sometimes of longer duration
than at others. These minute variations
are probably connected with peculiarities in
the state of the atmosphere, as I have said
above, which are worthy attention, because
they may be principally concerned in pro-
ducing many disorders of health which are
attributed to atmospheric influence: when
the weather is settled, when only diurnal cu-
muli prevail with westerly winds, then the
action of De Luc's column is the most regu-
lar; and this is found to be the most whole-
some kind of weather.”
* See Phil. Mag, June and July, 1811. Since the
Char, 7.37. of ELECTRICITY. 211
publication of the first edition, I have seen the superb
columns made by M. De Luc, himself. The varieties of
the action seem to coirespond with my own observations
on the instrument belonging to Mr. B. M. Forster, of
Walthamstow, which continued ringing (with varied
action) for a year, and which received the whimsical ap-
pellation of the perpetual motion.
*
P2
212 VARIETIES OF WEATHER. CHAP. s.
CHAPTER VIII. .
FURTHER INVESTIGATION OF PECULIARITIES
OF WEATHER. *.
If it can be shown, as above, that there are
varieties in the state of the atmosphere, with
which the prevalence of disease seems con-
joined, so that the said diseases may be refer-
red to its agency, analogy would lead us to
ascribe other diseases, for which no particu-
lar cause could be assigned, to some other
peculiarity in the air, which, however, might
not be demonstrable by any meteorological
instruments; and our inquiries will be di-
rected to discover in what such peculiarities
may consist. I have already shown that
the peculiarities of weather alluded to as
being accompanied by the great prevalence
of disorders, do not appear to consist in the
dampness, dryness, heat, cold, levity, or gra-
vity of the atmosphere, nor in the combina-
tion of any two or more of these, or any
other qualities of the air, demonstrable by
, meteorological instruments; but that, in
*
Chap. 8. VARETIES OF weATHER. 213
many instances, they appear to be marked
by the peculiar character and distribution of
the clouds, and the appearance of other
meteors; the relation of which to the state
of the thermometer, barometer, and hygro-
meter, have not been duly hoted; that is to
say, there has been no discoverable peculiarity
in the state of those instruments at the time:
but the actions of De Luc's aérial electro-
scope have been intermitted, or otherwise
irregular and inconstant.
As the peculiarities of weather alluded to
are characterised by difference in the distri-
bütion of the clouds in general, and of other
meteors, and do not consist in the varieties
of any one cloud in particular; and as the
former part of this work has related chiefly
to the varieties of individual modification, it
is purposed to consider briefly, in this place,
the characteristic circumstances of different
kinds of weather. In doing this, I have
taken examples of some of the most dissi-
milar varieties, though there are kinds of
weather partaking more or less of each of
them, so that the shades of difference are
innumerable, every day, perhaps, having
something different from all the rest in the
214 VARIETIES OF WEATHER. CHAP. 8.
year: and if the different states of weather
alluded to have any decided connection with
the varieties of the animal functions, their
effects must be very intricate and compound;
a circumstance which has always rendered
the knowledge of this connection so obscure
and imperfect. *
As there are many circumstances which
constitute particular kinds of weather, and
many combinations of these circumstances,
it will be proper to adopt some one as a cri-
terion, and speak of the combinations of the
others under that head.
The order of the clouds is the most obvious
feature in different kinds of weather, and
ought to be principally attended to. There
are several sorts of weather, which, to an
inattentive observer, would be called, in
common, fine wholesome weather ; but,
which, by a more minute observance, are
found to differ materially, both in their ap-
pearance and consequences. **.
A stratus early in the morning, greater or
less, according to the time of year, etc. evapo-
rating as the sun rises, the formation of well
defined hemispherical cumuli through the
day, most abundant soon after noon, and
Char. s. VARIETIES OF WEATHER. 215
disappearing again in the evening, to be suc-
ceeded by strong dew and a stratus, are the
circumstances which mark a settled and
wholesome state of the atmosphere, particu-
larly when accompanied by westerly gales;
which though they do not vary directly as
the sun's altitude, yet seem, in some measure,
to keep pace with it, and a calm succeeds in
the evening.
This order and distribution of the clouds
happens with different winds, and different
states of the thermometer; for it is not con-
fined to hybernal frost, nor to the heat of
the dog star. When it takes place, however,
the mercury in the barometer is seldom very
low, or variable. Indeed it may be said, in
general, to be conjoined with a mean state
of that instrument. This weather is of lon-
ger or shorter continuance, as may happen :
the appearance of cirrus and cirrostratus, and
above all, the fleecy and irregular look of
the cumuli, with sudden variations in tem-
perature and pressure, indicate a change.
Sometimes these appearances soon subside,
and the same weather returns. The cumuli,
too, occasionally become rocklike, approach
to cumulostratus, and spread, without ending
216. VARIETIES OF WEATHER. CHAP. 8"
in rain; but these are exceptions to the gene-
ral rule. When to such a continuance of
regular nubification, as described above, cir-
rocumulus supervenes, an increased warmth
often follows, and frequently without rain.
Occasional changes of this kind in the order
of the clouds, unattended by rain, took place
during the long drought, which continued
from Midsummer nearly to Michaelmas, in
the year 1800.
In days with the regular order of clouds
alluded to, I have found the action of De
Luc's electric column regular. Such days
often alternate with others in which dif-
ferent modifications appear; and very often
after, cumulostratus, accompanied by cirrus,
etc. has prevailed, for many days: nimbifi-
cation and rain take place ; after which,
only regular cumuli are observed again; as
if nimbification was a process which re-
stored the tranquillity of the atmospheric
electricity.
In spring and autumn we have frequently
a continuance of cloudless days, ushered
in by more or less of a stratus; but this
very clear kind of weather seldom takes
place about the solstices. The wind is usu-
CHAP. 3. VARIETIES OF WEATHER. 217
ally Easterly, varying more or less to North
or South, and often strong: the air dry; the
mercury of the barometer usually above the
mean altitude; and the range of the ther-
mometer, that is, the distance between the
maximum of the day, and the minimum of
the night, is considerable. The falling of
the dew in the evening, which is often plen-
teous, is indicated by the crimson or lake
colour of the horizon for some time after
sunset, which extends all around, except
perhaps, in the West, where the sky has a
deep and rich golden appearance, approxi-
mating more to red, to yellow, or to orange.”
* It is very difficult to commemorate precisely the
particular tints exhibited by clouds; yet this ought to
be done as accurately as possible: for the different co-
lours, refracted by the haze, with a horizontal sun, are
very various, on different occasions, though the sun's
distance from the horizon, either above or below, shall
be the same. The haze, at different times, refracts
almost every conceivable variety of purple, lake, crim-
son, orange, and yellow, and sometimes a brownish
colour. The colour of the haze should be distinguished
from that refracted by definite clouds. The latter also
refract a great variety of colours, and sometimes many
tints are seen in different parts of the same cloud. Though
the infinite shade of colours will ever prevent the adop-
tion of terms which shall define them precisely; yet a
218 VARIETIES OF WEATHER. CHAP. 8.
Nearly a week of such clear weather hap-
pened during Sept. 1811, and afforded
a good opportunity of making observations
on the brilliant comet which was conspicuous
that autumn. \
A fine line of cirrus, of great altitude
and length, is often the first sign that the
clear weather above described is about to
be changed for an atmosphere more variable;
and, in proportion as such kind of cirri in-
crease, and others, or clouds of other modi-
fications, succeed, we may judge of the
nearer or more distant approach of the
alteration ; and the weather about to follow
may, in general, be determined by the
general face of the sky, and of the kind of
modifications apparent during the progress
much better nomenclature for colours might be invented,
than has hitherto been done. It is obvious how indefi-
nite the present terms in common use are. How diſ-
ferent the red of the peomy from that of the papaver
rhaeas, and still more so from that of the papaver orien-
tale, or the scarlet lychnis. The yellow of the crocus,
or the marigold, from that of the evening primrose, or
the ranunculus pratensis. Perhaps the best mode of
forming a momenclature for colours, would be by refer-
ence to specific flowers, which may be considered as
standards.
CHAP. 8. VARIETIES OF WEATHER. 219
of the change. But the great clearness
above depicted often gives place to, and al-
ternates with a state of the atmosphere
marked by peculiar circumstances, which
seem to indicate a great disturbance, and
perpetual change in its electric state.
In such weather, the cirrus generally
appears soon after, and sometimes before,
sunrise, and prevails through the day, under
every conceiveable variety of whimsical fi-
gures, Comoid tufts, like bushes of hair, or
sometimes like erected feathers; angular
flexures; streaks; reticular intersections of
them, frequently at right angles, which look
like nets thrown over the firmament; forms
of arrows; stars with long fibrous tails;
cyphon shaped curves, and lines with
pendulous or with erect fringes, ornament
the sky; still different appearances of stars
and waves again appear, as these clouds
change to cirrocumulus and to cirrostratus,
which modifications also seem to form and
subside spontaneously, in different planes,”
* Clouds are said to be in the same plane, when at
equal distances from the earth; more properly, it is a
portion of a sphere, whose diameter is greater than that
of the sphere of the earth, by twice the distance from
the earth's surface to the cloud. We, speak familiarly of
the plane surface of water, which is actually spherical.
$220 VARIETIES OF WEATHER. CHAE. s.
and with the varied and dissimilar appear-
ances of flocks at rest; fleeces of wool, or
myriads of small specks; of long tapering
columns, like the tail of the great manis,
br of mackerelback skies, or of striae, like
the grains of wood. Cumuli have not now
their hemispherical figure; tuberculated, or
fleecy; elevated and flimsy, or heavily sailing
along like scud, they appear operated on by
an unusual condition of their causes. All
these circumstances, when viewed as per-
petually changing and appearing at different
times of day, and exhibiting innumerable
and dissimilar tints, according with the sun's
varying altitude, afford abundant amusement
for the speculative observer, who delights in
the highly diversified scenery of nature.
But when we observe the relation of such
multiform configurations of the clouds to
other phaenomena, the varying and irre-
gular action of De Luc's electroscope, the
irregular strength and duration of the winds,
the altitude of the mercury in the barometer, .
and to the state of other instruments, our
curiosity is enhanced; and our desire further
to develop the principles of such relations
becomes yet of more moment, when we
find atmospheric peculiarities, of which
CHAP. 8. VARIETIES OF WEATHER. 221
such appearances are tokens to influence the
growth of vegetables, and to affect the func-
tions of animal life.
The kind of weather above depicted,
continued through the chief part of the
autumn of 1810, during which time such
derangements in the action of the digestive
system, as are commonly called autumnal,
diseases, were remarkably prevalent, fol-
lowed by hypochondriasis, and other ner-
vous affections. It was in the same season
that the great mortality happened among the
plane trees above alluded to. The weather
of the said autumn was rather hot and dry,
till about the middle of October, when it
became damp, and rather rainy: but still,
there continued to be an unusual appearance
of the clouds during the intervals of fine
weather. A similar kind of dry weather
occurred again in the spring, 1811, attended
with similar phaenomena, and the irregular
action of the aërial electroscope. But the
summer and autumn following were remark-
ably fine and wholesome, and very warm,
though there were occasionally days in
which similar multiform and ever changing
configurations of the modifications prevailed.
222 VARIETIES OF WEATHER. CHAP. 8.
Even showery weather is characterized by
very different appearances of the clouds at
different times. The stupendous and moun-
tainlike cumuli and cumulostrati, which
appear in the intervals of summer showers,
have a different look from those which ac-
company the cold snow showers of spring,
with keen March winds. Indeed, the rock-
like cumulostrati, which are seen before such
snow, have generally a well defined, though
rugged margin, to appearance, and a pecu-
liar look of transparency, or clearness, which
is preserved even when they become dark
purple, or nearly black.”
I have slightly mentioned these circum-
stances, from a belief, that in general the
particular order and arrangements of the
clouds are not sufficiently attended to. It
is to be hoped, in future, that more attention
will be paid to this part of the subject. ‘t
* With such skies, I have known cold South winds;
and on other occasions, with different kinds of clouds,
hot northerly winds in spring. The peculiar appear-
ances which attend these exceptions to the usual coin-
cidence of phaenomena ought to be particularly attended
to.
+ There are many minute differences in the appear-
ance of the clouds, under different circumstances, which
4
Char. s. VARIETIES OF WEATHER. 228
I have not described, as every meteorologist must ob-
serve them for himself. Sometimes there is a wavy
appearance of the under part of a cumulostratus passing
over, which looks like the white foaming billows of the
ocean. This is generally a symptom of variable weather,
as is also the curling inward of the fleecy protuberances
of the cumuli, as they pass along in the wind.
224, OF TEMPERATURE CHAP. 9.
CHAPTER IX.
SOME MISCELLANEOUS OBSERVATIONS ON AT-
MOSPHERIC TEMPERATURE AND PRESSURE.
After the invention of the barometer and
thermometer, many important discoveries,
about the pressure and temperature of the
atmosphere were made by philosophers.
The knowledge, however, of their variations,
and therelations of these variations with other ,
phaenomena, remains still very obscure, and
leaves a wide field for future investigation.
When Galilaeo and Torricellus had dis-
covered, that the pressure of a column of
atmosphere was equal to that of a column of
mercury of equal base, and of about thirty
inches in height, and to a column of water
of the same base, and about thirty five feet in
height: but that the height of the mercury
or water, which balanced the column of air,
varied a little at different times, philoso-
phers began to measure the atmospheric
pressure by such means; and finding that its
6
HAP. 9. "AND PRESSURE. 225
variations were very irregular and uncertain,
and were not referrible to any known laws,
they began to investigate their causes.
Without detailing the particulars of the
observations made by philosophers, from
time to time, it will be sufficient to observe,
that the variations of pressure, as far, at least,
as we can discover, may be caused, 1st, by a
variation in the volume of atmosphere, the
density remaining the same; or, 2dly, by a
variation of density, the volume remaining
the same; or, lastly, by a variation in both
density and volume. But though these cir-
cumstances may be conceived capable of
effecting barometrical variations, yet it is
probable there may be many other causes
yet unknown. Many hypotheses have been
assumed to account for variations in the
density and volume: but, after all, these do
not seem capable of accounting for all the
phaenomena which attend alterations in the
atmospheric pressure. As it is not my
intention to detail former experiments and
hypotheses, I shall conclude this chapter
with a few simple observations on facts,
which I have made myself, many whereof
do not appear to have been noticed before.
It is a common bbservation, that the fall-
Q
226 of TEMPERATURE CHAP. 9.
*
ing of the mercury, when gradual, is followed
by long continued rain; when it suddenly
sinks, or sinks and rises alternately, by showers;
and when greater or more sudden depressions
take place, storms are generally the con-
sequence. These observations are, generally
speaking, true; though, perhaps, with occa-
sional and rare exceptions; for sometimes
the barometer shall sink, and even the clouds
present all the appearances of rain, and yet
the rainy symptoms shall subside, and clear-
ness return without any fall. But there
appear to me to be some other remarkable
connections between the state of the baro-
meter, and other phaenomena, which do not
appear to have been noticed.
Rain, as is known, sometimes falls with a
rising barometer; and, when this happens,
it is usually followed by fine healthy weather.
Some philosophers have called it rain of the
recomposition of the air.” And I have
noticed rain, with a rising of the mercury,
to be attended with circumstances which
seem to indicate a strong positive electri-
city.h
* Van Mons. Nicholson's Jour. Sept. 1809.
+ The strong and refreshing smell, which sometimes
results when showers first fall, after a long drought, is not
CHAP. 9. AND PRESSURE. 227
There is usually a warm and agreeable sen-
sation of the atmosphere attending such
rain, which is strikingly contrasted to the
cold and raw sensation occasioned by the
fall of thick wet mists, or rain which hap-
pens when, even with a northern or easterly
wind, the barometer and thermometer sink
together, and when the air has previously
been found to be negatively, or nonelectri-
fied. -
As far as we can determine, the air
appears capable of holding more water in
solution, in proportion as its temperature
and pressure is greater; and yet the ther-
mometer often rises when rain is coming
on, particularly in winter. This circum-
stance is not wholly irreconcileable with
what has been laid down, since the rain
may be occasioned by a diminution of
pressure, as is often manifestly the case,
an invariable attendant on them, even under these cir-
cumstances. The highly electrified water of summer's
thunder showers produces this smell the strongest; and
it is weakest with the cold, and, perhaps, nonelectric rain,
which sometimes falls after the condensation of a spread-
ing sheet of cirrostratus into nimbus, with a cold atmos-
phere.
Q 2
%28 OF TEMPERATURE CHAP. 9,
the barometer falling, or else by a super-
vening current of colder or supersaturated
air; and the rise of the thermometer,
which accompanies the fall of the baro-
meter in this case, may be owing to the
increase of temperature produced by the
condensation of the vapour in the case
of rain. But on what principle can we
account for the increase both of tempera-
ture and pressure, during such condensa-
tion? On the 20th and 21st July, 1811,
rain kept falling almost all day, with a
rising barometer, and no depression of tem-
perature, (making allowances for the inter-
ception of the sun's rays,) while evaporation
continued to be considerable.
It has been remarked by Mr. Howard,
that if the state of the barometer, during
any period of , the moon, be examined,
it will be found to have been highest or
lowest about the time of the full and new
moon, as may happen; but that the mean
state of that instrument usually happens
about the lunar quadratures. As far as
my own observations enable me to decide,
this connection is observable in the majority
of instances.
Cºurs, AND PRESSURE, 229
I once thought that the mean state of
the barometer of a given number of days'
observation varied, in some measure, ac-
cording to the moon's perigee and apogee ;
that is, that it was higher with the latter
than with the former: but subsequent re-
searches convinced me, that the exceptions
were almost as numerous as the cases cor-
responding to the rule.
f introduce the above circumstances here,
merely that they may become the subjects
of the future observations of meteorologists
in different places; as I think they are
worthy of a stricter examination than has
hitherto been made.*
* {f the place of the moon has such an effect on the
atmosphere, as to influence the barometrical pressure, it
may probably produce other varieties in the state of the
air, which may influence the nervous system and animal
functions of persons in particular kinds of disease. It is
thus that it may have an effect on persons of such deranged
intellect, as is termed lunacy, who are said, in some cases,
to be worst about the full of the moon.
There are many other instances of periodical pa-
roxysms of different complaints, and some of them very
curious; but how far, and in what manner, solar and
lunar influence is concerned, cannot be precisely deter-
mined. Some persons have had paroxysms come on at
particular hours of the night, and have, for a long time,
230 . OF TEMPERATURE CHAP. 9,
g
awoke at those hours. To try how far the imagination
has been concerned in producing the discases, clocks have
been altered to deceive the patient, but without avail,
The reader may consult the Zoonomia of Darwin, and a
recent work in France, by Ph. Pinel, Arnold on Insanity,
Crighton on Mental Derangement, and others who have
written on this subject.
Since the first edition of this book, I have conversed
with Dr. Spurzheim, about the periodicity of disorders of
health. He considers it as more or less affecting every
body. The doctor is now employed in publishing a
large work on the newly discovered anatomy and phy,
siology of the brain.
w
Chap. 10. OF SUPERSTITIONS. 231
CHAPTER X.
OF SEVERAL SUPERSTITIOUS NOTIONS WHICH
APPEAR TO HAVE HAD THEIR ORIGIN IN AN
OBSERVANCE OF CERTAIN METEOROLOGICAL
PHAENOMENA.
There is a natural tendency in the human
mind, arising from the mutual influence of
the different organs of the brain, and the
consequent association of ideas, to attach
notions of good or evil to those objects
which have been observed to precede or
to accompany pleasurable or painful cir-
cumstances: hence the origin of many su-
perstitious opinions.”
From such association of ideas many
animals were anciently worshipped, either
as good or evil spirits; and even at a later
period, when their worship was rejected as
superstitious, or useless, they were consi-
* In the figurative language of the ancients, facts were
often ascribed to contemporaneous remarkable circum-
stances; hence the influence of Procyon or dog days, the
blustering of the stormy Orion, and many others; see a
memoir Sur l'Origene des Constellations et l'Explication
de la Fable, by M. Dupuis.
232 of METEOROLOGICAL Char. 10.
dered as foreboders of evil or of good.
Many of these superstitions originated in
the observance of facts, ascribable to at-
mospheric influence.* Thus, certain birds
being affected by peculiarities of the air,
previous to thunderstorms, or other terrible
events, and showing signs of their affections
by particular habits, were found to be fore-
boders of tempests, hurricanes, and other
dangerous atmospheric commotions; and
they were subsequently considered as evil
omens in general, gaining, as it were, an
ill name by their utility as monitors. So
the crow, garrulous before stormy weather,
was afterwards regarded as a predictor of
general misfortune. Many animals too
were considered by the ancients as in-
fluenced by human prayers and supplica-
tions.t. In this manner the observation of
* Some observations on the physical origin of such
superstitions may be found in Cicero's work on Divi-
nation.
* + Ego quae timebo,
Providus auspex
Antequam stantes repetat paludes,
Imbrium divina avis inminentum,
Oscinem corvum prece suscitabo,
* Solis ab ortu. Horatius.
CHAr. 10. SUPERSTITIONS. 233
maay real facts laid the foundation for su-
perstitions, which terrified the ignorant, and
which the designing, made use of in order
to acquire respect, and to aggrandize their
own power. Hence the rise of sorcerers,
augurs,”, and other impostors, the interpre-
ters of omens and portenta, who pretended,
in the peculiar flight and song of birds, to
read the destinies of monarchs and of na-
tions. It is probable that out of a number
of such predictions, some might happen to
be true, where the sagacity of the augur
penetrated farther into probable events than
the ignorance of the multitude; and this
fortuitous coincidence enhanced the public
credulity, strengthened the empire of su-
perstition, and became a fatal impediment
* Consuluitgue stryges nostro de Sanguine, etin me
Hippomanes foetae semina legit equae.
Propert. lib. iv. eleg. v. 15.
Aristophanes, laughing at the dependance upon the
predictions of augurs, makes the birds ludicrously chant
their importance in the following words:
Eggsy 3' vulsy, Apºgov Agapoi Awdown poige Awoxxwy
Exºgyrs; yog aparrow sw’ pºsig ºrw ºpog awayta terriffs,
234 OF METEOROLOGICAL Char. 10.
to the progress of science throughout suc-
ceeding ages.”
It may be proper to examine a few cases
in point, for the sake of illustration. Among
all the birds of evil report among the
ancients, the owl stands foremost, as being
the most generally regarded as the har-
binger of mischief and of death. Pliny,
the natural historian, represents the large-
eared or horned owl, strix bubo, as a fune-
real bird, a monster of the night, the abomi-
nation of human kind. And Virgil de-
* Among many remains of augury extant at the pre-
sent day, may be enumerated the common practice among
our farmers, of nailing up dead kites, crows, owls, weasels,
and other rapacious animals, against the doors of barns
and outhouses: a custom which originated, as Apuleius
informs us, in an endeavour to terrify the infaustae aves,
and warn them not to obtrude themselves upon the family;
the superstitious often imagining that, by avoiding the
omen, they could avert the impending mischief. Quid,
istas nocturnas aves, cum penetraverint larem solicité prae-
hensas forilus videmus adfigi, nisi quod infaustis volatibus
familiae minantur exitium, suis luant cruciatilus.
Apul. Met. lib. iii.
+ Bubo funebris et maxime abominatus publicis prae-
cipue auspiciis, deserta incolit, nectantum desolata sed
dira etiam etinaccessa, noctis monstrum, nec cantu aliquo
CHAP. 10. SUPERSTITIONS, 235
scribes its death howl from the top of the
temple by night; a circumstance probably
introduced here by the poet, as a precursor
of the death of Dido.” Ovid constantly
speaks of this bird as an evil omen; f
and the same notions respecting it may be
found among the effusions of most of the
ancient poets: † indeed, there is scarcely a
vocalis, sed gemitu. Itaque in urbibus aut omnino in
łuce visus dirum ostentum est.
Plin. Hist. Nat. lib. x. c. 12.
Quis quaeso ovum bubonis videre possit, cum tam avem
ipsam vidisse prodigium sit. Plin.
* Solaque culminibus lethali carmine bubo
Saepe queri, et longas in fletum ducere voces.
Virg. Aeneid. iv. 462.
# Foedaque fit volucris, venturi nuncia luctus
Ignavus bubo, dirum mortalibus omen.
e Ovid, Met. v. 550.
Eumenides stravere torum tectoque profanus
Incubuit bubo, thalamique in eulmine sedet.
Ovid. Mei. vi. 432.
Ter pedis offensi signo est revocata, ter omen
Funereus bubo lethali carmine fecit.
Ovid. Met. x. 452.
Tristia mille locis Stygius dedit omnia bubo.
Ovid. Met. xv. 791.
f Nocturnaeque gemunt stryges, et feralia bubo
Damna canit. Stat. Thebaid. iii. 511.
236 OF METEOROLOGICAL Char. 10.
poet, ancient or modern, who does not speak
of the owl in this point of view.”
The bird called by the Greeks 392g, seems
to be the same as the Roman bubo, and was
also reckoned an ominous and ill fated bird.º.
Hic vultur, illic lucifer bubo gemit.
* Senec. Herc. Far. 686.
Bubilat horrendum ferali carmine bubo
Humano generi tristia fataferens.
Epig. de voc. av. et quad. Anthol. vet.
Lat. Ep. cxliii. 33.
Quod trepidus bubo quod strix nocturna queruntur,
Quod strident ululantgue ferae. Lucan, lib. vi.
* The superstitious opinion, that the owl is the harbin-
ger of death, still prevails among the ignorant of modern
Europe. In England, no village ghost, or fairy dance,
mo pizgy maze, or haunted house, is more common than
a death foretold by the owl.
The remarkable appearance of the upright shadows in
some foggy moonlight nights, as well as some curious
atmospheric refractions, have probably cooperated with
ocular spectra, in giving birth to the monstrous relations
of nocturnal spectra and apparitions, which so mightily
terrify the country peasants.
+ Jam si historicos consulas apud Dionem in morte
Augusti, cum decrevit senatus, ut publice supplicaretur
propter ejus valetudinem, tore ovyºlov kºsiggsvov supsºn,
waſ £42; wreſ &rrs kºnºsyo; #303s.—Et in morte Commodi
Bwag &T’ owts (xxſitaxis) #8wās, etc.
* Bochart. Hierozoicon, lib. ii. e. 22.
See also Arist. Hist. An. Hib, viii. c. 3.
4
CHAP.10. SUPERSTITIONS. 23?
Some authors, too, have considered the
xzxzi as the owl: Homer identifies this
bird with the 2upwºog,” also supposed by
some commentators to be the owl.f. The
striking and peculiar look of this bird; its
occasional and uncertain appearance in
towns; and its loud and dismal cry, uttered
often when all other birds are quiet, as
well as its being the bird of night, are the
circumstances which, aided by an occasional
coincidence of events, have caused the owl
to be regarded in the light of an evil omen.
This, and similar superstitions, will appear
less surprising, when it is considered that
crafty and designing persons had an interest
in their propagation.
The dread attached to owls seems to have
been extended to other birds of the night;
a circumstance which rather corroborates
the idea that they were dreaded, in a great
measure, from being companions of dark-
ness and obscurity. Spencer has given us
* Køxiēz axxºgº.go. 930 &yºpe; ta kupiyºoy. Homer.
+ There are a great variety of names for the owl, as
well as for other birds, which, by all writers, except natu-
ral historians, since the time of Linnaeus, appear to have
been used, in a great measure, promiscuously.
238 OF METEOROLOGICAL CHAP, 10,
a most woeful catalogue of harmful fowls,
in the second book of the Fairie Queene.*
The hollow booming of the bittern from
the pool on a still evening, and the hoarse
sound of the nycticorax and fernowl, are
equally striking; may be easily imagined
plaintive; and seem capable, when uttered
in the stillness of evening, of exciting ideas
of melancholy; and of inducing in the minds
of the vulgar and ignorant an idea of their
being connected with misfortune.f 3
The cornix of the Romans was another
bird represented as ominous, who, by his
* Even all the nation of unfortunate
And fatal birds about them flocked were,
Such as by nature men abhorre and hate,
The ill faced owle, death's dreadful messengere;
The hoarse nightraven, trump of dolefull drere;
The leather winged bat, daye's enemy;
The ruefull strich still waiting on the bere;
The whistler shrill, that whoso hears doth die;
The hellish harpies, prophets of sad destiny.
Spen. Fairie Queene, lib. ii. 12, 36.
The harpy has been supposed by some to be the Mada-
gascar bat.
+ How sweetly did they float upon the wings
Of silence, through the empty vaulted night, ,
At every fall soothing the raven down |
Milton's Comus.
CHAP. 10. SUPERSTITIONS. 239 '
croaking, prognosticated evil; * but, whe-
ther the cornix was the raven, or the crow,
or, indeed, of what species, is uncertain. It
was, however, some bird of this genus; and
to identify the species is of more conse-
quence to the natural historian than to the
meteorologist. It does not appear that the
cornix was the same bird as the corvus.
The augurs appear to have represented one
as a bird, which was ominous croaking on
the right hand, namely, the corvus; and the
other, on the left hand, the cornix; as
observed by Cicero f in his book of Divina-
* Saepe malum hoc nobis, simens non laeva fuisset,
De coelo tactas memini praedicere quercus,
Saepe sinistra cava praedixit abillice cornix.
Wirg. Ecl. i.
Quod nisi me quacumque novas incidere lites,
Ante sinistra cavà monuisset abillice cornix.
Pirg, Ecl. ix.
See also Plin. Hist. Nat. lib. x. c. 12.
The word sinistra here seems to refer to a Grecian
superstition about ill omens being given on the left hand.
of which our poet was mindful when he said,
“That raven on yon left hand oak,
Curse on his illbetiding croak l’’
f Gay. Fal. &c.
+ Jupiterne cornicen a laevă, corvum a dextrā canere
jussisset? Cicero de Divin, lib. i. c. 7.
1
240 OF METEOROLOGICAL CHAP. IG.
tion, and afterwards by Bulengius, in his
book on Augury.
The picus was also another of the oscines,
whose voice was feigned injurious to tra-
vellers.” This fable might have been
founded on observing the garrulity of the
bird before rain; which might become an
impediment to a journey. Linnaeus repre-
sents this bird to have been the woodpecker,
or pickatree; but it is difficult to identify
the names and species of birds spoken of
by the ancients.t. The parra was another
bird with whose illportending song Horace
cursed the impious.j.
Cur a dextra corvus, a sinistra cornix faciat ratum.
* •A Cicero de Divin. lib. i. c. 39.
Some make the Greek topo.é to be the Roman corvus,
and the English crow, and the Greek nopolyn to be the
cornix of the Romans, and the raven of Great Britain.
Linnaeus, however, has called the raven corvus corax,
and the crow corvus coronae. I refer the reader to Aelian,
Aristotle, Pliny, Gesner, and Aldrovandus.
* Tequc nec laevus vetetire picus
Nec vaga cornix. Horat.
+ Picus may be only masculine of pica the magpie; a
bird which, in windy and stormy weather, I have observed
to be garrulous, and to fly high in small flocks, uttering
its cry. *
f Impios parrae recinentis omen
Ducat. Hor. Od.
‘CHAP. 10. SUPERSTITIONS. 241
It was long ago observed, as mentioned
in another chapter, that the frequent immer-
sion of certain fowls in the water portended
rain; and they were, consequently, con-
sidered unlucky alites; while others, who
never dived, were regarded as good signs;
a fact observed by Niphus in his book of
augury, who quotes a verse to that effect
from Aemilius.* And Virgil makes Venus
predict the safety of the Trojan fleet to
Aeneas from the flight of swans.#
Another familiar instance of the effect of
association of ideas is the following—Vul-
tures, who prey on carcasses, naturally fol-
* Cygnus in auspiciis semper laetissimus ales,
Huncoptant nautae quia non se mergit in undis.
Niphus de Auguriis, lib. 1. c. 10.
+ Namque tibi reduces socios classemque relatam,
Nuncio et in portum versis aquilonibus actam,
Ni frustra augurium vani docuere parentes,
Adspice bis senos luctantis agmine cycnos,
Aetheria quos lapsa plaga Jovis ales aperto,
Turbabat coelo; nunc terras ordine longo,
Aut capere aut captas jam despectare videntur.
Ut reduces illi ludunt stridentibus alis,
Et coetu cinxere polum, cantusque dedere,
Haud aliter puppesque tuae, pubesque tuorum,
Autportum tenet, aut pleno subit ostia velo.
Wirg. Aeneid, i. 400.
R
242 OF METEOROLOGICAL CHAP. 16.
lowed armies, and inhabited the field of
battle after the conflict: the ancients, there-
fore, associated their appearance with de-
struction, and they became evil omens, par-
ticularly when following armies.*
There is a superstitious respect paid to
the swallow, in many parts of the country,
at the present day. Their nests are pro-
tected, and it is considered unlucky to
molest them by accident: this is a very old
Opinion, mentioned by many writers: and
the circumstances of their building so close
to the habitations of man indicates, I
think, that they have long enjoyed freedom
from molestation.f For animals seem to
regulate their conduct according to circum-
stances: and it is not only that the indi-
* Potter has some observations on this in his Antiq.
- Graec. and refers to Plutarch, Aristotle, and Pliny.
+ the martlett
Builds in the weather on the outward wall,
Even in the force and road of casualty.
Shakspeare,
Odimus accipitrem quia semper vivit in armis,
Et pavidum solitos, in pecus ire lupos,
At caret insidiis hominum quia mitis hirundo,
Quasque colat turres chaonis ales habet.
Ovid. Art. Amat. ii. 150.
CHAP. 10. SUPERSTITIONS. 243
vidual learns to avoid danger, but the whole
species seems by degrees apprized of the
state of either enmity or amity between
them and man, and to act in conformity
with this knowledge. There are parts of
oriental India, where the religion of the
Brachmans, protects animals from injury, in
which hawks and other birds are so fami-
liar and daring, as to Snatch the food from
out of dishes, as men are carrying them
from the kitchen to the place of repast.
The respect paid to the swallow may have.
originated in its being the harbinger of
spring, and from its inhabiting churches,
temples, and other sacred places ; and, per-
haps in some, measure, from its utility in
clearing the air of insects." Swallows, at
one time, among the Greeks, appear to
have been regarded as an evil omen when a
flock of them settled on a tent, or ship.
* Orebono volitans muscas deprendit hirundo,
Atque ita viventi pascitur illa cibo.
Quumque lacus circumvolitet vel florida prata,
Illius ambages quis numerare potest?
Cypselus at vacuo rapidis volat aethere pennis
Necmetuit milvos accipitremve feram.
Epig. Incert. Auct.
-R 2
244. OF METEOROLOGICAL CHAP. 10.
The low flight of swallows predicts rain,
and their settling on buildings is an au-
tumnal custom previous to their departure,
or to the commencement of wintery wea-
ther; hence have they, perhaps, been con-
sidered as portending evil.
The crowing of cocks was reckoned
ominous, particularly as prophesying the
event of wars. It is from the known
courage of this bird in combat, that he
Was Sacred to Mars, and called Ageos vaorros
by Aristophanes. The gallicantus presaged
the victory of Themistocles over the Per-
sians; and the feasts Axext puzºvoy diſºv were
called so from this event, and were cele-
brated by fighting cocks. And a victory
of the Boeotians over the Lacedaemonians
was also said to be foretold by the cocks.
There are, besides the above, many other
Superstitions relating to cocks, all, appa-
rently, coming from some observance of
fact. At a later period, cocks were said to
crow all night about Christmas time, a fable
adverted to by Shakspeare in Hamlet.*
* Some say that ever gainst that hallowed season,
At which our Saviour's birth is celebrated,
£HAP, 10. SUPERSTITIONS. 245
This fancy is easy of explanation; for the
crowing of the cock being the announcer
of the dawn of light, he is said to crow
all night at that season of the year, which,
though really the darkest, namely, midwin-
ter, was the season at which the light of
Christianity was said first to dawn on the
darkness of the Pagan world. There is a
remarkable circumstance about the crowing
of cocks. At several different times in the
course of the night, a general crowing may
be heard, from all quarters, where there
are cocks: the first that begins, apparently
setting all the rest off; and this fact is re-
markably striking in places where numbers
of cocks are bred for the purpose of fighting.
As far as I can observe, excepting at the
dawn of day, these crowing matches hap-
pen at very irregular and uncertain periods.
The ancients, however, seem to have re-
garded them as taking place at marked in-
The bird of dawning croweth all night long.
The nights are wholesome, then no mildew falls,
No planet strikes, nor spirits walk abroad;
No fairy takes, nor witch hath power to charm;
So gracious and so hallowed is the time.
Hamlet,
246 OF METEOROLOGICAL CHAP. 16.
tervals of time which appear to have caused
their division of the night watches by the
first, second, and third, Axexteopovias, as
mentioned by St. John.”
They say that if a dead kingfisher be
hanged up by its bill, its breast will always
the turned to the quarter from whence the
wind bloweth; this when the wind is strong
may be accounted for mechanically from its
shape, but it is asserted to be the case always;
and the bird called therefore the natural wea-
thercock...f
It is an old observation, that the appear-
ance of a certain beetle, called tenebrio mor-
tisagus, was a presage of death, which may
be founded on observation. For the appear-
ance of the insect may, in reality, forbode
the death of sick persons in the housewhere
it is observed; since the same peculiarity of
atmosphere which may bring out the beetle,
may be such a one as would produce the
death of the patient.
* Some observations of this may be found in vol. i. of
Dr. Hales's Analyses of Ancient Chronology, 4to. Lon-
don, 1810.
+ See Pseudonia Epidemica, by Dr. Brown, 2d edit.
p. 104.
CHAP. 10. SUPERSTITIONS. 247
If it be by some such association of ideas
as what has been above described, that most
of the superstitious devotion paid to parti-
cular birds and animals has originated, the
worship of the Ibis, and of the Scarabaeus
in Aegypt, and of many other animals in
Asia and Africa, might prove, if we were
able to trace them, to have sprung from a
similar source.*
The popular persuasion, that if it rains
on the 15th July, called St. Swithin's day,
it will rain some part of each day for forty
days, may be ranked among superstitious
notions originating in atmospheric phaeno-
mena; for though the placing the prognostic
at St. Swithin's day must palpably be the ef-
fect of ignorance and credulity, yet there
may be some natural reasons why, if rainy
weather occur about that time of year, it
will be of some continuance, which I have
noticed for many years to be the case.
In parts of Wiltshire, they say, it is un-
lucky to look at the new moon, for the first
time, through a glass; showery weather
* Some animals appear to have become sacred, from
their absolute utility, as the tame Ichneumon in parts of
Aegypt.
248 OF METEOROLOGICAL CHAP, 10.
about that time of the moon, which might
keep the spectator in doors, and make him
see her crescent first through a window,
may be a bad prognostick for the month.
The ignorant run out of doors and turn the
money in their pockets, if they hear by
chance of her first appearance. Many people
positively assert that Friday is always either
the fairest, or the worst day in the week:
what this originated in, unless it were some
casual occurrence of a succession of fine
and of wet Fridays, I know not. Numerous
other similar errors of reason might be
added, were it necessary to confirm the
unlucky devotee of fable and fancy, who is
cursed for walking under a ladder, or toward
whom the salt fell on a Friday, that he is per-
verting physical truths by his own disturbed
imagination. The idle tales about Pandora
and about Fortune, and many others, are
referrible to a physical origin. Idleness too
is a great propagator of superstition. The
inactivity, anxiousness, and mystic feelings
of some minds, viewing the great uncer-
tainty of future events, and the casualties of
life, render persons more disposed to trust
to their stars than to their wits, who con-
CHAP. 10. SUPERSTITIONS. 249
tent themselves with praying to the goddess
not to crush their fabric, and, like Horace of
old, sing
“Injurioso ne pede proruas
Stantem columnam.”
While others of a different turn of mind,
preferring prudence to fancy, and choosing
rather to apply their shoulders to the
wheel than to call on Hercules, chant the
more sensible song of
“Nullum numen habes si sit Prudentia, quamvis
Te facimus Fortuna deam coeloque locamus.”
The different successess in life of these
two kinds of persons are well discussed in
Miss Edgeworth's excellent story of Murad
and Sanadin.
It would be foreign to the present subject
to consider here any superstitious opinions
which are not referrible to meteorological
phaenomena; and only a few of these can
be selected, for want of room. Any capa-
ble person, however, who would write a
general history of superstitions, and endea-
vour to trace each to its particular source as
nearly as possible, arranging them according
45& OF METEOROLOGICAL, &c. Char. 10.
to the age or country in which they prevailed,
and including all degrees of superstitious
opinions and customs, from those which
have gained importance from their extensive
prevalence, and the influence they have had
on the manners and destiny of different
people, down to the meanest subject of
terror to the village peasant, would render
considerable service to the cause of truth.
Such a book, translated into different lan-
guages, and distributed among different
nations, might be of great use, in clearing
up many injurious fables and preparing the
way for useful knowledge.
APPENDIX.
C. 1. § 4. p. 14. l. 12.—THE sudden and dense fogs
which come on sometimes seem hardly referrible to
any assignable cause. In great cities, the fog, whatever
may be its cause, aggrandized and thickened by smoke,
and the breath of the inhabitants, often envelopes the
whole town in such darkness, that people are obliged
at mid-day to go about their business by candle light.
Of this, I select the following instance from Mr.
Howard's Journal, which happened on the 10th Jan.
1812:—“ London was this day involved, for several
hours, in palpable darkness. The shops, offices, &c.
were necessarily lighted up; but, the streets not being
lighted as at night, it required no small care in the
passenger to find his way, and avoid accidents. The
sky, where any light pervaded it, showed the aspect
of bronze | Such is, occasionally, the effect of the
accumulation of smoke between two opposite gentle
currents, or by means of a misty calm. I am informed
that the fuliginous cloud was visible, in this instance, from
a distance of forty miles. Were it not for the extreme
mobility of our atmosphere, this volcano of a hundred thou-
sand mouths would, in winter, be scarcely habitable !”
An account of several remarkable circumstances at-
tending particular fogs may be found in Bertholon,
252 APPENDIX.
Elec. des Meteors: also an account of the remarkable
fog which overspread part of Europe in 1783. See vol.
ii. 128. of the above work, sur l’Extraordinaire Brouil-
lard de 1783. w
C. 2. § 7.—A disposition in the air sometimes to
form rain, without the precurrence of the modifica-
tions, may be deduced from the drops of rain which
sometimes fall without any visible clouds, even when
the sky is clear. The drops, probably, acquire size in
falling.
C. 2. § 11. Hail.—It is a question, Whether hail
results merely from the coldness of the atmosphere in
which the nimbus pouring it exists, or whether some
other causes may not be deemed necessary? Certainly
there is a difference in the general appearance of the
cumuli, cumulostrati, &c. which precede hailshowers,
and showers which only effuse rain. The Abbé Ber-
tholon has observed, that hard hailstorms are generally
accompanied with thunder and lightning, and that the
loudest thunder generally happens when the hail has
been greatest. “La tonnerre gronda, sans interrup-
tion, pendent la châte du fameuse grèle observé par
M. de Ratte à Montpellier, le 30 Janvier, 1741. Il
en a été de même dans un grande nombre d'autres cir-
constances.” Elect. Met. ii. 195. ch. Sur la Gréle et le
Gresil. In the same work, vol. ii. cc. 6 and 7, the
author has treated amply on the peculiarities of hail and
SI] OW.
C. 5–To ascertain that our health is influenced by
atmospheric peculiarities, is a discovery of little practical
utility, unless it enable us to provide an antidote against
their effects. The difficulty of guarding against such
disorders as seem to be caused by the state of the air,
APPENDIX. 253
must appear manifest to all who consider the obscurity
which hangs over this subject, both as to the peculiar
quality of the air which excites the disorders, and as to
the state of constitution of the patients in whom they
may occur. As we do not know the nature of the spe-
cific stimulants which excite many atmospheric or other
diseases, nor any particular counteracting antidotes, in
medicines, we must be content to prescribe a general
mode of conduct to those in health, which, by preserving
a strong and tranquil condition of body, may avert or
mollify the influence of the atmosphere on the constitu-
tion, and to endeavour to restore those already disorder-
ed, by measures that are generally known to conduce to
such a state of health. It may not, therefore, be entirely
foreign to the present subject, to discourse briefly on the
mode of preserving the healthy, and of rectifying the
disordered, actions of the animal machine. Early rising,
good air, and exercise, freedom from care and anxiety,
and temperance of appetite, have been from time imme-
morial the popular receipts for health and longevity; but
the quantity of exercise necessary, the quantity of our
food, and the periods of taking it, and its quality, which
involves the question of natural diet, must be submitted
to a more accurate and physiological scrutiny, which may,
in a great measure, explain the ill success of many who
labouring under disorder, yet think themselves entitled
to health from the observance of an imagined course of
temperance. Exercise should be taken to a considerable
degree, but by no means when the stomach is full.
Various experiments have long ago established it as
certain, that digestion is never so well performed, as
when a meal is followed by rest; and carnivorous ani-
mals, and, indeed, all those who take in their food in
2
254 APPENDEX.
any quantity, rest or sleep after their repast. Exercise,
under favourable circumstances, seems to give vigour to
the whole system; and strength, appears, to a certain
degree, to be commensurate to bodily exertions, and
health, and, spirits, are the consequence. Indeed few per-
sons know how rightly to appreciate considerable and
constant exercise in the open air as a medical agent and
preserver of health. But it is probable, that the same
vital energies, which are concerned in all the movements
of muscular activity, and of thought, and which custo-
mary language has ascribed to the brain and nervous
system, are engaged after taking our food in the work of
digestion, And it has been found, conformably to this
notion, that exertion after meals has interrupted the
chylopoietic processes, and has caused unpleasant feel-
ings in the stomach, and subsequent weakness. Great
mental exertions, or anxiety, have had the same effect.
The gentle stimulus of company after dinner, may, per-
haps, be beneficial, by assisting to produce those nervous
energies, which hard exercise might dissipate among the
muscles at a time when they ought to be spent on the
stomach, that that organ might pour out sufficient of
the gastric juice, to convert the alimentary matter into
chyme, and subsequently on the liver, pancreas, and
secretory coats of the intestines; that by the after aid
of their proper fluids, the chyle may be properly formed
for absorption and nutriment. Exercise, while these
processes are going on, may be regarded as an interrup-
tion to them: though, if used several hours after eating,
it appears often to assist the peristaltic action of the in-
testines,
The food is the next subject of consideration. It
has been often said, that, in a natural state, the
*
APPENDIX. * £55
quantity and quality of our food would be regulated by
desire and opportunity: but as "we know little about
man in a natural state, we must regulate our diet by the
experience of what is best in a state of artificial society.
Physiologists have laid great stress on proportioning the
quantity of food to the power of the stomach; and it is
rational to consider, that what is not digested, will irri-
tate the surfaces of the alimentary canal, and cause many
sympathetic diseases. Hunger is, in health, the general
criterion of the power to digest; but, in disorder, aş
Mr. Abernethy has observed, the uneasy feelings of a
weak stomach are often mistaken for it. {
Custom has, in artificial life, appointed meals at cer-
tain stated hours; a practice which does notappear to have
arisen wholly from oeconomical convenience, but which
may have been established, partly in order to embrace
the beneficial results of conviviality, which consist in the
pleasurable sensations, and, perhaps, better digestion,
occasioned by cheerful company during and after meals.
The wassail bowl, though abused by posterity, was, pro-
bably, suggested by the sagacity of our forefathers, as
a salutary pleasure. The periods of eating should not
come too near together. People fall into a mistake often
by supposing that persons with weak stomachs should eat
little, and frequently; whereas they ought really to allow
considerable time for the digestive organs to recruit their
strength. And many who for ill health have tried vari-
ous kinds of food without success, have found great bene-
fit from a long fast before dinner. Of the quality of
food proper for man, much has been said and written by
physicians in all ages, and various have been their opi-
nions. Many have enjoyed good health who have
subsisted entirely on a vegetable diet; while others have
6
256 APPENDIX.
grown weak, and have not been sufficiently nourished by it.
In some particular diseases patients have not been able
to eat vegetable food, and in others animal food has ap-
peared injurious; but we must not draw our conclusions
of the wholesomeness of any particular food from its ef-
fects on diseased subjects. There are many idiosyncrasies
which must be regarded as exceptions to general rules :
some persons cannot eat honey, others butter, others
other things, without being ill. There are persons who
can eatallmeat but mutton which never digests with them.
It may be proper to consider, first, what sort of food
is best in health: and, secondly, what may be the me-
dical influence of different -changes of diet in cases of
disorder. With regard to the first of these questions,
little enough can be expected from any hypothesis of
the cause of diseases. It is a question to be solved by
an accurate examination of facts. We cannot even
place much dependance on the aflāk gy of the human
structure to that of any other animal; for though the
structure of the human organs of digestion most resemble
those of carnivorous animals, yet the monkey tribe,
which, in many respects, approach nearest in their na-
ture to man, live on vegetable substances. Several wri-
ters of physiology have asserted, that those persons who
feed on a mixture of animal and vegetable food are
stronger and more active than those who subsist entirely
on vegetables; while the advocates for a pure vegetable
diet contend, that it produces more tranquillity, and
even a more mild and amiable character. These two
assertions are by no means irreconcileable, and agree
very well with experiments and observations that I have
made, which have had a tendency to show that animal
food produces more muscular strength and energy, but,
APPENDIX. , 257
*
at the same time, renders the body more susceptible of
irritation. When, to patients who have long subsisted
entirely on vegetable food, flesh has been superadded,
the pulse has become quicker, the muscular motion more
quick and lively, the countenance more highly coloured,
and the spirits exhilarated. These effects are strikingly
conspicuous just after the adoption of the meat, and illus-
trate the greater degree of stimulus afforded by animal
food: and the contrary effects often appear on first taking
to vegetables alone. But after a time, in either case,
à very similar state of health often returns: a fact which
illustrates the great power of accommodation to circum-
stances, which the human constitution possesses.
But though there be persons enjoying health on each
diet; yet, upon the whole, the mixed diet seems to
agree best with the majority, and also to produce rather
more strength and vigour. But whether health main-
tained on a mixed diet be equally lasting, or whether it
may not eventually lead to disease, is a question to solve
which accurate experiments are as yet wanting. It has
been said by those who contend for a vegetable diet,
that, being natural, it conduces to a more perfect form
of body, and greater degree of intellectual power. The
assertion, however, seems not to be supported by facts;
for the antient Greeks, who may be admitted as exam-
ples of the more perfect forms of our species, and who
possessed a clearness of intellect, and vigour of imagi-
nation, superior to their neighbours, appear to have
lived on a mixed diet; whereas the inhabitants of part
of India, who subsist wholly on vegetables, dre very far
from either bodily or mental excellence.
For the medical advantage of vegetable diet, much
- more may be said, than for its common use. To illus-
trate the view I have of this subject, I must observe,
S
./
258 APPENDIX.
that the effect of animal food seems to be that of in-
creasing all the vital energies, or actions, of the animal
machine: while a person is in health, when these ac-
tions are natural, to increase them is to augment the
strength and power of the animal: but, in diseases where
there are morbid actions, to increase them is to aggravate
the disease. It is probably on a similar principle that
vegetable diet and distilled water are useful in diseases,
where the diseased actions seem as fully established as
the natural ones, as in cancer, for instance. Besides
this, in common and more trifling cases, a mild diet
may become a useful alterative, and, by alleviating the
irritation of the chylopoietic organs, may subdue nume-
rous sympathetic diseases, which accompany a disordered
state of the viscera. This lowering of the animal ac-
tions by vegetable food has sometimes disposed me to
differ from those who regard animal food as equally con-
ducive to longevity, and to incline to the fanciful opinion
of others, who have regarded the vegetable diet of the
early ages as the cause of the Patriarchal longevity, as
if man lived longer by living slower. All reasoning of
this sort must, however, be very vague and conjectural.
The question, whether the animal system wears out
sooner in proportion as it is stimulated to action, either
by animal food or any thing else, provided that stimulus
does not proceed to cause actual disease, must rest
entirely on experience. There are some remarkable
instances of men, of what is commonly termed genius,
that were characterized by perpetual activity of thought
who have died prematurely: but there are several means
of accounting for this. Men of genius are men of great
sensibility, who are frequently led into excesses in eating
and drinking, particularly the latter, which shortens
their lives, Indeed, the stimulus of wine and spirits,
APPENDIX. 259
so uniformly destructive, seems, in a great measure,
conducive to the enterprizes of genius. By exciting a
system, already highly susceptible, into violent action, it
gives, for a time, a flow and vigour to thought, but
which is ultimately exhausting. Such persons seem to
keep up an habitual state of excitement, similar to that
which ordinary persons occasionally make use of pre-
vious to any unusual mental exertion, who take drams
as a stimulus. After all, notwithstanding the violence of
stimuli is lessened by habitual use, from the diminution
of excitability, it is doubtful whether the moderate sti-
mulus of animal food actually hastens dissolution. Old
Parr and Jenkins do not appear to have fed on a vege-
table diet; and the longevity of Cornaro seems to have
depended more on his moderation in diet, than on the
quality of his food. Animal food is certainly as easily
and as soon, if not sooner, digested; and to state the
question of diet fairly, would be to say, in cases where
from the healthy state of the digestive organs, the chy-
lopoietic functions go on perfectly, what difference is
subsequently observable between the effects of the mixed,
and those of the purely vegetable nutriment? I was
once inclined to attribute much good to the vegetable
regimen as general diet; but subsequent experiments
and observation have made me somewhat sceptical on
this point. Animal food appears to afford more nourish-
ment, in proportion to its volume, than vegetables.
There may, perhaps, be minute differences in the quality
of the blood, arising from different kinds of food, which
evade all chemical tests; but, as we know nothing of
these, we ought not to be deluded by hypothetical argu-
ments on the subject. As the digestive processes are
those of assimilation, the blood seems more likely to be
deteriorated by bad chylification and absorption of un-
assimilated matter, arising from disorder in the organs,
s 2
260 APPENDIX.
than from the quality of the aliment, when the stomach
is healthy. In disease, the blood may be altered in com-
position, from various sources; the liver and other se-
creting organs not giving out their proper fluids, and
these remaining in the blood may alter its properties,
and increase and render compound the evil of sympa-
thetic irritation.
To preserve health, of which we are in actual pos-
session, and to cure disorders when once established,
are certainly very different things: in the latter case,
various kinds of diet, like medicines, having specific ac-
tions arising from the nature of the disorder, particular
regimen may become necessary, in some particular com-
plaints, which it is foreign to the purpose to discuss
here: but, in general, the treatment of diseases seems
more simple than is usually imagined. As the secondary
and outward symptoms of diseases are infinitely nume-
rous and dissimilar, both as to their local effects on the
body, and as to their influence on the mind, arising
from varieties of constitution and other circumstances,
the only rational and simple mode of treating them
seems to be, to find out, if possible, whether, among
the multiform symptoms, there he not some circum-
stances common to all diseases, and which are the distin-
guishing marks of disorder in the system. The antients
seem to have pursued and acted upon this simple mode
of investigation: and perceiving a manifestly disordered
state of the digestive viscera to accompany the more ob-
scure irregularity in the nervous actions, had recourse to
remedies which had known effects on those organs; and
they treated successfully the more apparently mental
diseases, by rectifying the state of the viscera. The
manner, the mind, and nervous system, and the diges-
tive organs, mutually aggravate each other's disorder;
and the insufficiency of local remedies n general, for
APPENDIX. 26%
the cure of local diseases, has been ably illustrated by
physiologists of late; which illustration may be regard-
ed as the only important progressive step the science
of medicine has taken since the time of Hippocrates.
These opinions seem spreading on the continent, as may
be learnt by the works of the French physicians, Hallé,
Cabanis, Pinel, and others. Dr. James Hamilton, Dr.
Curry, Dr. Cheyne, and some others, have, in this
country, illustrated the connexion between the unhealthy
state of these organs and diseases in general: and Mr.
Abernethy, the perusal of whose surgical works first
induced me to consider these subjects accurately, has
shown the great success of the constitutional treatment
of local diseases; and has treated in a very scientific
manner of the disorders of the constitution, in which
they orginate, and of the mode of treating them; to
which works I refer the physiological reader.
I cannot help observing, in conclusion, that the pur-
suit of this subject strongly impressed me with sentiments
of its importance, in a moral point of view. For if
disorders in the digestive functions, which are so easily
occasioned, and which are remediable by early attention,
be capable, by getting ahead, of exciting the system in
such a manner as to produce innumerable forms of bodily
disease, and frequently to affect the operations of the
mind; considering how general are these disorders, and
the mistaken habits which produce and aggravate them,
we cannot but regard them as principally efficient in
producing the quantity of intellectual depravity, which
is so widely conspicuous; and by weakening the mind,
and perverting the character, as impeding the progress.
of science, and the advancement of truth. That the
air, which seems to effect such great changes of the
blood in the lungs, should, when its quality is peculiar,
1. -
263 APPENDIX.
by affecting those organs and the skin, cause great chan-
ges in the whole system, is no matter of wonder; but
surely all these effects must be greatest on a weakened
and disordered constitution. The way, then, to become
prepared against atmospheric influence, is to tranquillize
and invigorate the constitution by a systematic plan of
temperance, founded on physiological views of the na-
ture and offices of the chylopoietic viscera, and of the
connexion of their disorders with those of remote organs,
and of the system in general; and, at the same time
to adopt habits of seasonable exercise abroad, and to
enhance, by moral discipline, an habitual state of mental
tranquility, to which such habits tend. For by joining
measures, which seem primarily to ameliorate the cone
dition of the nervous system, with those which more
directly regulate the chylopoietic organs, we place the
functions of the animal system in a state the most favour-
able to health, which gives the greatest scope and range
to intellectual exertion, and which fortifies the body
best against the numberless diseases which the varieties
of climate, and of atmosphere, may have a tendency to
produce on the various degrees of strength and the pecu-
liarities of organization of different individuals.
The reader who wishes to pursue further the effect of
atmosphere on health may consult Cabanis Rapport du
Moral et du Physique de l’Homme. 2d vol. pp. 1. 161.
C. 6–There are some circumstances about winds
very remarkable, and which seem inexplicable on any
hitherto invented hypothesis. The gusts of wind, in
some high windy weather, seem to fluctuate in a manner
somewhat analogous to the undulatory motion of waves.
This fact may be easily seen by a pendulous anemometer.
When the wind is accompanied by the rain, the periods
of the gusts may be counted by the intervals of the
§
APPENDIX. 263 .
more or less violent impulse of the water on the windows
opposed to the wind, or leaves of any tree twined across
them.*
In the Phil. Trans. vol. xlviii. 1. is related a curious
instance of a violent gust of wind, which succeeded a flash
of silent lightning, and came from the same quarter.
Winds.-Refer to D'Alembert's Reflections sur les
Causes Générales des Wents, and to several papers in Phil.
Trans. *
The number of different currents blowing at the same
time at different altitudes, is a circumstance I as-
certained by the following experiments. On the 25th
Oct. 1809, a gentleman, named Wallis, sent up a small
inflammable air balloon from Clapton, in Hackney: the
balloon was made of varnished paper, quite water proof,
three feet six inches in diameter, and filled with inflam-
mable gas. The process of filling it was begun at one
o'clock in the afternoon; and by about ten minutes
after two, the balloon appearing sufficiently inflated, a
small paper parachute was attached to the bottom of it,
by means of touch string. It was now found that the
buoyant power of the balloon was just sufficient to carry
the appendage. Upon the touch string being lighted,
the balloon was launched into the air. At first it ascend-
ed very slowly in a direction nearly W. N. W. and
in less than a minute dropped the parachute, which fell
into the brick field opposite Hackney New Church.
The balloon now ascended more rapidly in the same
direction for several minutes, when, being very high,
it met a different current of air, and was observed to
travel nearly towards the South: this was ascertained
* The philosopher watching this, as he lies in bed by night, must be
very careful to preserve his vigilance, as it is a most soporific sound.
No lute of Mercury, or Aeolian harp, is more lulling to the Argus eyes
of the studeht.
264. APPENDIX.
by the balloon's getting much more southward without .
increasing or diminishing in apparent magnitude, which
it would have done, if it had taken a course either much
to the East or the West of the South. In a few minutes
more its course was again altered by a third current of
air, which carried it in a direction apparently, N. E.,
when it passed again over the northern part of the parish
of Hackney, and was distinctly seen from the place of
its ascent. At about twenty minutes before three, it
was blown by a fourth current nearly N. N. W. by N.
Thus there appear to have been four different currents
above one another, namely, E. S. E.--N.—S. W. and
S. S. E. by S. It very soon became invisible to the
naked eye, but was, discerned through a telescope till
about ten minutes before three, when, the person who
sent it up observed it to sink very rapidly, after which
it was no more seen.. & - “... s.
At the time the balloon ascended, the mercury in
the barometer, 30 feet from the surface of the earth,
stood at 30. 28. Thermometer (Farenheit) 574. , Hyg.
0. 5. Wind variable and very gentle: a few clouds in
the sky of the modification of cirrus. tº-
This air bakloon fell at five minutes before five, the
same day at Wilbraham, near Cambridge. The sud-
den diminution of the angle of its altitude, which has
been called its sudden descent, could not be occasioned
by any rent in the balloon, since it afterwards travelled
nearly fifty miles. At ten minutes before three it appear-
ed in the telescope to be well distended: it is therefore
probable, that at that time it had attained its greatest.
elevation. Its motion was, therefore, horizontal; and
it being about twenty-five miles in the hour, and direct
from the eye of the observer, it would, without any
descent of the machine, occasion a rapid alteration of
the angle subtended by the line of its perpendicular al-
APPENDIX. 265.
titude. The diminution of the angle being rapid in
proportion to any other observation, it was concluded
that it must have been at that time descending, because
we could not at that moment know the velocity of the
current, which the time and place of its descent have
since proved to be very great.
A small balloon launched the same day went uni-
formly in the same current of air. Since the above,
I have made upwards of thirty experiments with air
balloons, some filled with inflammable gas, and then
with rarefied air. Some few of them have gone uni-
formly with one direction, but most have indicated four
or five, and some seven or eight, different currents of
wind: the currents below, too, have several times ac-
quired successively the direction of those which had pre-
viously blown above. * *
C. 7. Electricity.—Though the antients might be un-
acquainted with the science of artificial electricity, yet
they appear familiar with many electric phaenomena,
as observed by M. PAbbé Bertholon, in his Ouvrage
de l’Electricité des Meteors, 2 vols. 8vo. d Lyon. 1787,
vol. i. p. 67. The same author refers to a Dissertation,
by M. Ostertag, De Auspiciis ex Acuminibus. Some
observations on this head may be found too in the Mem.
Phil. Soc. Manchester. Among other accounts I tran-
scribe a part of the observation of the Abbé Bertholon,
as follows: from his work above alluded to. *
“ Des Phénomenes d'Electricité Naturelle, observés par
les Anciens.—Quoique la découverte d'electricité du ton-
nerre soit toute récente, on en trouve cependant chez
les anciens des traces si certains, et si sensibles, qu'on,
ne sauroit endouter avec fondement. Nous allons rap-
porter plusieurs preuves qui établissent cette assertion
d’une maniére irréfragable; elles sont appuyées sur des.
faits qu'on avoit eu de la peine à expliquer avant la con-
266 APPENDIX.
noissance de l'electricité atmosphérique. Il conste par
Hérodote qu'on pouvoit, il y a plus de deux mille ans,
attirer la fondre avec une pointe de fer ! Selon cet auteur,
les Thraces désarmoient le ciel de ses foudres en déco-
chant des fleches en l'air, et les Hyperboréens en lan-
çant pareillement dans les nuées, des piques améres
d'un fer pointu. Ces usages sont autant de points qui
conduisoient à la decouverte de l'électricité que les Grecs,
les Romains, connoissoient par certains effets qu'ils at-
tribuoient aux puissances célestes, comme M. Ostertag
l'a prouvé très au long dans une dissertation de Auspiciis
ex Acuminibus.
* Au rapport de Pline, les annales font foi qu'au
moyen de certains sacrifices, et de certains formules,
on peut forcer la foudre à descendre, ou du moin
l'obtenir du ciel. Une ancienne tradition porte que
cela a été pratiqué en Etrurie chez les Volsiniens, à
l'occasion d'un monstre nommé Volta, qui, après avoir
ravagé la campagne, étoit entré dans leur ville, et que
ce fut leur proprerio, Porsenna, qui fit tomber sur ce
monstre le feu du ciel. Lucius Pison, écrivain d'un
grand poids, décrit au premier volume de ses annales,
qu'avant Porsenna, Numa Pompilius avoit fait souvent
la même chose ; et que, pour s'être écarté du rit prescrit
dans l'imitation de cette pratique mystérieuse. Tullus
Hostilius fut lui-même foudroyé parmi les bois sacrés,
comme de nos jours M. Richmann l'a été à Petersbourg,
en répétant l'expérience de Marly-la-Ville avec trop peu
de précaution. Tite Live rapporte le même fait de
Tullus Hostilius. Les anciens avoient admis aussi un
Jupiter Elicien, Elicium quoque accepimus Jovem.
Jupiter qui, dans d'autres circonstances, étoit appellé
Stateur, Tonant, Férétrien, avoit dans cette occasion
le nom d'Elicien. Pendant la nuit qui précéda la vic-
toire que Posthumius remporta sur les Sabins, les jave-
APPENDIX. 267
lots Romains jettoient la même clarté que des flambeaux.
3Lorsque Gylippus alloit à, Syracuse, on vitune flamme
gur la lance. Gylippo Syracusa petenti, visa est stella
super ipsam lanceam constitisse. In Romanorum
castris visa sunt ardere pila, ignibus scilicet in illa delap-
sis: qui sæpe, fulminum more, animalia ferire solent et
arbusta, sed si minore vi mittuntur, defluunt tantum
«et insident, non feriunt nec vulnerant.* Suivant Pro-
cope, le ciel favorisa du même prodige le fameux Beli-
saire dans la guerre contre les Vandales.f On lit dans
Tite-Live, que Lucius Atreus ayant acheté un javelot
pour som fils, qui venoit d'être enrólé parmi les soldats,
cette arme parut embrasée, et jetta des flammes pendant
plus de deux heures sans être consumée par le feu.f
Plutarque, dans la vie de Lysandre, parle d'une appa-
rence lumineuse qu'on doit rapporter à l'électricité: dans
le chapitre trente deuxieme il fait emcore mention de
deux faits de cette nature. ** In Siliciâ militibus aliquot
spicula, in Sardiniâ muro circumeunti vigilias equiti,
Scipionem, quem in manu tenuerat, arsisse, et littora
crebris ignibus fulsisse.” Les piques de quelques sol-
dats en Sicile, et une canne que portoit à sa main un
cavalier, em Sardaigne, parurent em feu. Les cótes fu-
rent aussi lumineuses, et brilloient de feux fréquens.
Pline a observé le même phénomene. J'ai vu, dit-il,
une lumiere sous cette forme, sur les piques des soldats
qui étoient em faction la nuit sur les ramparts, vidi noc-
turnis militum vigiliis inhærere pilis pro vallo fulgorem
effigie ea—hominum quoque capiti vespertinishoris magno
præsagio circumfulgent. § Cesar, dans ses Commen-
taires, rapporte que pendant la guerre d'Afrique, après
* Senec. Natur. Quaest. lib. i. cap. !.
+ Procop. de Bell. Vandal. lib. ii. cap. 2.
f Tite Live, livre xliii.
§ Plin. Hist. Nat. lib. ii. -.
ā
268 APPENDIX.
un orage affireux, qui jetta toute l'armée Romaine dans
le plus grand désordre, la pointe des dards d'un nombre
de soldats brilla d'une lumiere spontanée; phénomene
que M. de Courtivron * a appliqué le premier à l'élec-
tricité. Rapportonsici tout au long le passage de Cesar.
Vers ce temps-la parut dans l'armée de Cesar un phé-
moméne extraordinaire, au mois de Fevrier: vers la
seconde veille de la nuit il s'eleva subitement un nuage
épais, suivi d'une grèle terrible ; et la même muit, les
pointes des piques de la cinquième légion parurent s'em-
flammer.
** Per id tempus ferè Caesaris exercitui res accidit in-
credibilis auditu, nempè vigiliarum signo confecto, cir-
citer vigilia secunda noctis, nimbus cum saxea grandine
subito est cohortus ingens; eâdem nocte legionis quintae
cacumina sua sponte arserunt.*f-—Tous ces faits que nous
vemons de tirer des anciens, prouvent qu'om a dit avec
raison, que pour juger sainment des ouvrages des an-
ciens, il faut penser qu'il y a beaucoup de fabuleux dans
leurs histoires, et beaucoup de vérité dans leurs fables;
que nous croyons trop facilement les premiers, et que
nous n'examinons pas assez les secondes pour entirer les
vérités utiles qu'elles renferment. Joignons ici d'autres
faits analogues, observés par les modernes, qui tous
prouvent l'indentité rigoureuse qui regene le tonnerre et
l'électricité.
Sur um des bastions du château de Duino, situé dans
le Frioul, au bord de la mer Adriatique, il y a, de
temps immèmorial, une pique dressèe verticalement la
pointe en haut: dans l'été, lorsque le tems paroit tourné
à l'orage, le soldat qui monte la garde en cet endroit,
examjne le fer de cette pique, en lui présentant de près
* IIistoire de 1'Académie, [752, page 10.
+ Caesaris Comment. de Bello Africano, cap. vi.
APPENDIX. 269
le fer d'une hallebarde (brandistoco,) qui est toujours
là pour cette èpreuve: et quand il s'appercoit que celui
de la pigue étincelle beaucoup, ou qu'il y a à sa pointe
une petite gerbe de feu, il sonne une cloche qui est auprès,
pour avertir les gens qui travaillent aux champs, ou les
pècheurs qui sont en mer, qu'ils sont ménacés du mauvais
tems; et sur cet avis tout le monde rentre. La grande
ancienneté de cette pratique est prouvée par la tradition
constante et unanime du pays, et par une lettre du P.
Imperati benedictin, datée de 1602, dans laquelle il
dit, en faisant allusion à cet usage des habitans de Duino:
“ Igne et hastà hi mire utuntur ad imbres, grandines
procellasque praesagiendas, tempore praesertim aestivo.”
M. Watson rapporte, dans les Transactions Philoso-
phiques, i que, selon plusieurs rélations venues de France,
M. Binom, curé de Plauzet, avoit assuré, que pendant
vingt-sept ans qu'il y a résidé, les trois pointes de la croix
du clocher paroissoient environneis d'un corps de fiamme,
dans les grandes tempètes; et que quand ee phénomene
s'étoit montré, la tempète n'étoit plus à craindre, le calme
succédant aussi-tòt. M. Pacard, secrétaire de la paro-
isse du prieuré de la montagne de Breven, vis-à-vis le
mont Blanc, faisant creuseur les fondemens d'un chalet
qu'il vouloit construire dans les prairies de Plianpra, il
survint un violentorage, pendant lequel il seréfugia sous
un rocher peu éloigné, et il vit le feu electrique tomber à
plusieurs reprises sur la tète d'un grand levier de fer
planté en terre qu'il avoit laissé en se retirant.f Si on
montesur la cime d'une montagne, on pourra ètre electrisé
dans certaines circonstances immédiatement, et sans ap-
º Lettera di Gio. Fortunato Bianchini. dott. medic. intorno un nuovo
fenomeno elettrico, all. Acad. R. di Secinze di Parigi, 1758. Memoires
de l'Académie des Sciences, 1764, page 408, et suiv.
i Transactions Philosophiques, tom. xlviii. partie 1, page 210.
i Voyage dans les Alpes, &c. tom. ii, p. 56.
27Os APPENDIX.
pareil par une nuée orageuse, comme le sont les pointes
des girouttes et des mâts, c'est ce qu'ont éprouvé en 1767,
M. M. Pictet, de Saussure et Jallabert, fils, sur la cîme
du Breven. Le premier de ces sçavans, à mesure qu'il
marquoit sur son plan la position de quelque montagne,
en demandoit le nom aux guides qu'on avoit pris, et pour
la leur désigner, il la montroit du doigt en élevant la
main. * Il s'appercut que chaque fois qu'il faisoit ce geste,
il sentoit au bout de son doigt une espece de frémissement,
ou de picotement, semblable à celui qu'on epreuve lors-
que l'on s'approche d'un globe de verre fortement élec-
trisé." L'electricité d'un nuage orageux, qui étoit vis-à-
vis fut la cause de cette sensation. L'effet fut le même sur
les compagnons et les guides du voyage; et la force de
l'electricité augmentant bientôt la sensation produite par
l'electricité, devint à chaque instant plus vive, elle étoit
même accompagnée d'un espece de sifflement. M. Tal-
lebert, qui avoit un galon à son chapeau, entendoit au
tour sa tête un bourdonnement effrayant, que les autres
personnes entendirent aussi quand elles mirent ce même
chapeau sur les têtes. W
On tiroit des etincelles du bouton d'or de ce chapeau,
de même que de la virole de métal d'un grand baton.
L'orage pouvant devenir dangereux, on descendit à dix
ou douze toises plus bas, où on ne sentit plus d'electricitè.
Bientôt après il survint une petite pluie, l'orage se dissipa,
et on remonta au sommet, où on ne trouva plus aucun
signe d'electricité.*- Berth. Elec. Met.
P. S. Mr. Howard mentions a luminous appearance
in the clouds, on the 31st March, 1812, as * an exten-
sive appearance of light in the clouds to the West, with
rapid coruscations passing through them, in the manner
of an aurora borealis. This phaenomenon was apparent-
* Voyage dans les Alpes, &c. tom. ii. page 55 —Histoire de l'Aca-
démie, 1767, page 33.
APPENDIX.
271
tuate
i
truments
ºnuºſeAænd asotu ºsº[qeņ933A uo ºsſetuțuy ºuøyw go 88Se38ıq qºtſ AA
1I]S
*ºpuſą Kroņeužlyſ go 9oueuedddw 4594 el pue qsuță
ºpąoņou sºļoņºottºong ſo ‘ēļaujºsotoſ qeqAA
irty minutes.
*uututo!) S, onrI aCI Âg
·iºnauonoalq &q suopeoſpui，
ºleuauouøbųā Ļeņoſseooo Jðiņo Jo ‘oſeſſ “Suoºņºſ， ºžuļuqqºyſ JeqqaqAA
ºo? ºurſe） y so Kuujoys Jaqqaqa 'uºqņeæAA atņ Jo 0oue ſeaddy Ieuauaſo
ºpnoÍO Jo suoņeogſpoſºſ
șºurogſun 80Aou Jo ‘sºsnÐ ug 8į puțAA 9q) JøqnºqAA
* 1949uuoueuv ue ſq pºuquuqayap ‘puțAA aqh go 2010 I
ºsuooſteg uļy do spmoto &q uÅouſ ºdoqe 8ļuaianº) Jo suoņ09ațCI
ºpuțAA 9113 go uoņoarțCI
ºuoņeAxasqO ,seſ ºouſ 8 uºſ ſeg uſe? I go Ángulan@
hich observations on the
ºuoņeauesqo ,seſ aouſs toņedodeAg go 899.Jºaq
(*8,91ms8neſs) x3) ºugou3&H yoºņeņS
It continued twenty or th
*dºņaudoueg jo qq$țæH
2 3 4 5 6 7 8 9 to 11 12 13 14 15 1617 is 19
l
* 1949ulouunºtſ J, jo qq;äțøH
ºuoņeð 198q.O jo eſmių ſu puſe unoſą
ºuoņeAxesqO Jo KeōI puſe “qquoſq ºuva x y
I refer the reader also to various accounts of the Feux
St. Elme, and other curious electrical phaenomena, in
Bertholon Elec. Met. above quoted.
I subjoin the following plan of a more perfect kind of
ly not more elevated then the cloud then occupying the
meteorological journal, than I have hitherto observed in
sky, and was certainly not produced by a light s
Nicholson's Phil. Jour, March 1812.
COIIllſºn OI) tº Se II, W
below them.
of meteorology, &c. should be made several times a day.

~）;
• *- *** * *
yº <}.
ExPLANATION OF THE PLATES.
Pl, J. Fig. 1.
Fig. 8.
Pl. II. Fig. 1.
. Fig. 2.
Fig. 3.
*- Fig. 4.
Pl. III. Fig. I.
Fig. 2.
Fig. 3.
Fig. 4.
Pl. IV. Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Pl. W. Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 2. *
g
Represents a comoid cirrus. This is the variety called
the Mare's Tail. -
A cirrus lengthened out into a long pointed tail,
above it is a long straight Hinear cirrus.
Are cumuli; others are seen below them in the distance.
Cirrus beginning to change to the cirrocumulus.
The cymoid cirrostratus, a stormy feature of the cloud.
Nascent cumuli forming in the top of the straius soon
after sunrise.
A fine thin stratus ascending in the morning.
A cirrocumulus.
A cirrostratus seen in profile. -
A mottled cirrostratus, there is a cirrocumulative
tendency in its burred nebeculae. 4.
Another long cirrostratus seen in profile in the horizon.
Another cirrus figured like the cyma of architecture.
Lines of cirrostratus.
The same cloud breaking out into cirrocumulus for
being influenced by the cumulostratus below.
Cumulostratus. Many of the long cirrostrati alight on
its summits.
A nimbus pouring rain.
The cirrose crown.
A dense feature of cirrocumulus, often seen before
St0rms.
Little cumuli entering the storm from below.
Pi. VI. (Frontispiece.) Fig. I. A halo.
* Fi
g. 2. A double halo. -
Fig. 3. A discoid or coronoid halo.
Pig. 4. A corona or burr.
Fig. 5. A parhelion.
Fig. 6. A caudate meteor or falling star.
THE END,
C. Baldwin, Printer,
New Bridge-street, London.
： ~~~~
!
|-"， …’- ·
ſº： …º.º.º.， Z.，|-^ ae



ºraz z º.º.º.，,，e^*， º* e *， .

-ſae ae.|
. . . . . .---|-
（~~~~ …
：：： ~~~~
· · · -
.*ºnºvº º ſº zawaer.|-„aeaeae


|.*，，+.* * *^^ ------ -vaevae aer.

||×|-|-
ſz： ， ， ,
| T.：|-
|-
|-|-
|-
| 2
ſae.（. . . .|-
|-|
. . . . . .
| . . .
|-
|-
|× º， ，…ºº^， º aer.


non ).
| CIRCULATING
* ~ --- ---------rºr---- ~- - -- ~~~~ —
&
$
*t
t;
liſtſ
--
!
i.
}
|
#
3 9015 02802 1163
B518.






gº
Aſ ' ， , ， .
■ ■
t. ºA s. 4...）.3.5，...）,„ſae
►ae