Encyclopaedia Britannica, or, a Dictionary of arts, sciences, and miscellaneous literature : enlarged and improved. Illustrated with nearly six hundred engravings > Volume 13, MAT-MIC

c
^ Williams
on the Cli¬
mate of
Britain.
5
Importance
of the fci-
M E T E 0
trees and hedges in the fpring, fhould likewife be re-
marked, and compared with the ftarting up grafs on the
highly manured paitures in the neighbourhood of towns,
and on thofe alio affilted with manure, as well as the na¬
tural herbage on the commons and waftes. Some at¬
tention fhould be paid to the effects of thunder florms,
in deflroying the aphis and other deflrudlive infedls, the
peft of fruit and hop plantations; and the firft appear¬
ance ot the mildew or ruft on wheat fhould be particu¬
larly obferved, and remarks made to afcertain, whether
or not the moifture, w'hich occafions the difeafe in its
commencement was attended with wind and rain, or a
clofe damp hate of the air. The different kinds of foil,
where the crops, from the difeafe, fuffered moff, fhould
be noticed, and the fituation of the land for ventilation,
with the height of the fences, fize of inclofures, and vi¬
cinity to coppices, trees, or hedge-rows
The importance of the fludy of meteorology requires
little elucidation. In climates where the fucceflion of
feafons is nearly dated and regular, where the periods
of parching drought or deluging torrents, of the tempef-
tuous hurricane or the refrefhing breeze, are fixed and
afcertained, mankind has little to do, but expeft the
dreaded changes, and provide againft their devaftations j
but in countries like our own, where all the viciflitudes
of feafons may take place in the courfe of a few hours,
it is of the higheft confequence to invefligate the nature
of the change, and the circumflances that precede or
accompany it. I o the farmer, the mariner, the tra¬
veller, the phyfician, meteorology is in fome meafure a
lludy of necellity 5 to the philofopher it is a ftudy of in-
tereft and delight ; and to the obferver of nature it af¬
fords objects of grandeur and fublimity not to be found
in any other department of his favourite fcience. Surely
nothing can contribute more to elevate the mind of man,
to raife it “ from nature up to nature’s God,” than the
contemplation of the fweeping whirlwind, the dazzling
lightning, or the awful thunder.
Our limits wdll not admit of our entering into a hif-
torical detail of the progrefs of meteorology; but it
may be proper in this place to enumerate the principal
writers on this fcience both in our own country and on
the continent.
In this country, we may reckon Dr Kirwan, (in his
“ Eftimate of the Temperature of different Climates”),
R O L O G Y.
his “ Elfay on the Variations of the Atmofphere,” and lufred^
in the Infh I ranfa&ions”, Mr John Dalton (chiefly tion.
m the “ Manchefter Memoirs”), Col. Capper (in his ^
“ Obfervations on the Winds and Monfoons”), Mrw/’
Williams (in his “ Climate of Great Britain”), an<WoL“
Mr Luke Howard (in the Philofophieal Magazine),Jogy.
as the principal cultivators of meteorological know¬
ledge j and on the continent, the names of Cotte
( Traite de Meteorologies and Journal de Physique}
Sauffure C“ Ejfaifur l'Hygrometrie” and Voyage aux
Alpes”\ De Luc (a) Recherches fur les Modifica¬
tions de VAtmofphere f “ Idees fur la Meteorologie f and
other works), and Lamarck (fee Journ. de Rhijf paf-
fim) ft and moft confpicuous in this branch of natural
fcience.
In confidering the fubjea of meteorology, we may y,
properly divide it into feven general heads : 1. Of the
changes which take place in the gravity of the air ♦,
2. Of the changes of the temperature of the air ; 3. Of
the changes produced by evaporation and rain ; 4. Of
the changes produced by winds 5 5. Of atmofpherical
elefliicity j 6. Of meteors, or thofe vifible phenomena
accompanied with light, which take place in the atmo¬
fphere or near the furface of the earth ; and, 7. The
application of the principles of meteorology to the ufe-
ful purpofes of life. Of thefe heads, the fifth has been
already fully confidered under Electricity, and much
of the fixth has been exhaufted under Meteorolite.
The remaining circumftances will form the fubjeds of
the following chapters.
Chap. I. Of the Changes which take place in the
Gravity of the Air.
Many of the fads relating to this part of our fubjed
have been already anticipated under the article Baro¬
meter, and feveral circumftances fall to be confidered
more properly under Pneumatics than in this place.
We lhall here confine ourfelves to a general view of the
changes in the gravity of the atmofphere, as indicated
by the barometer, in various fituations on or near the
furface of the earth, and briefly examine the conclufions
that may be drawn from them.
The moft general fad indicated by the barometer is, Mercury
that this inftrument ftiews us the weight of a column offtands ’
air higheft at
the level of
——— the fea.
(a) In again mentioning the name of a philofopher fo refpedable as M. de Luc, we embrace the firft oppor-
tumty of doing him juftice, and of vindicating his charader againft an unfortunate mifconception of the late Pro-
ieilor Robifon, a miftake which we have inadvertently contributed to difleminate, by quoting Dr Robifon’s ftate-
ment in our account of Dr Black, where M. de Luc is accufed of having arrogated to himfelf Dr Black’s difeo-
very of latent heat.
M. de Luc’s vindication of himfelf (as printed in the I2th number of the Edinburgh Review) is before the
public. We owTe it to candour and jultice to acknowledge our convidion that Dr Robifon was too hafty in his af-
jertion, and that M. de Luc, fo far from arrogating to himfelf the dodrine of latent heat, has, in various parts of
ms numerous writings, exprefsly mentioned Dr Black as the auTior of that dodrine. This will appear from the
following citations. In his “ Introdudion a la Phyfique terreftre,” p. 102, M. de Luc thus expreffes himfelf. “ Ne
connoiflant point \e feu latent, dans la vapeur a toute temperature, dont la premiere decouverte ef due uu Dr Black,
&c. Again, p. 232. of the fame work. “ Ce qui developpoit 1’idee de chaleur latente par laquelle le Dr Black
avoit dejigne ce phenomenef—and at p. 385, “ Le Dr Black ayant decouvert qu’une certaine quantile de chaleur
dilparoit quand la vapeur de I’eau bouillante fe forme, nomma ce phenomene chaleur latente dans la vapeur.”
We trull that thefe quotations, with M. de Luc’s own jullification of himfelf above referred to, will be fufficient
to exculpate him from the charge of literary felony fo warmly brought againft him by Profeffor Robifon; and we
have no doubt the Profeffor himfelf, were he ftill alive, would under fuch evidence retrad his accufation.