(O84 
This circumftance induced M. Guyton 
de Maryeau, who has never let flip any 
opportunity of being ufeful, to examine 
the theory of the produétion of that me- 
teor. He feconded the philanthropic 
views of his countrymen, by unfolding 
this theory in an excellent Memoir pub- 
difhed inthe ournal de Phyfique for Ja- 
nuary 1777, under the title of a “* Letter 
from M. de Marveau to M. de Montheil- 
Jard, on the Influence of the Ele&tric Fluid 
on the Formation of Hail.” 
Some years afterwards M. Buiffart, of 
the Academy of. Arras, who was'totally 
unacquainted with the work of M. de 
Montbeiliard, read to that Society a Me- 
moir on the different advantages, that 
might be derived from the multiplicicy of 
electric conductors. This Memoir may 
be found in the 21ff volume of the fame 
journal.* 
Though thefe feveral performances had 
called the attention of the public adminif- 
tration and of opulent proprietors to a 
fubje& of fuch importance, and fince the 
firft publication of the ideas of Mefirs. 
Guenat de Montbeillard, Guyton de 
Morveau, and Buiffart, numberlefs difaf- 
ters caufed by hail in various parts of 
France had demonftrated the very great 
utility of the meafures propofed, or of 
others afcertained to be more efficacious, 
or more eafily executed, yet it was not 
known that more than one proprietor en- 
deavoured to put in practice any method 
of preventing this f{courge. 
In an interefting Memoir prefented 
about the middle of the year 1%03 to the 
Academy of Dijon, by M. Denize, a merm- 
ber of the Scientific Society eftablifled at 
pets ee ee SN ST 
-* A plan for correcting and regulating the 
anomalies of the atmofphere in general, 
founded.chiefly on the application of artificial 
condu€tors of elettricity, wes publicly an- 
nounced at Leicefter fo long fince as the year 
1793, in which year numerous perions were 
killed by lightning in various parts of, Eng- 
land. Jn Skinner’s late work on Peru is 
given a fet of queries and anfwers arifing out 
of a confideration of the fame principle, and 
tending to prove that the Andes and other 
high movntains efieét naturally in all coun- 
tries what might be effected artificially by 
meéans of elevated conductors. The opinions 
onthis fubje& which have appeared in Eng- 
Jand are certainly independent of any publi- 
cation in France, and have arifen from a con- 
fideration @ pricri, of the properties and ac- 
tion of the power called elefric, united to an 
attention to the meteorological phenomena, 
which chara@terize the vicinity of high 
snountains. ! 
4 
Account of the Means lately employedin France [July }, 
Megon, containing an inveftigation of the 
means of difperfing ftorms and preventing 
hail, is to be found a curious indication of 
a cuitom praétifed for many years: in va- 
rious diftviéts, of difcharging fire-arms on | 
the approach of ttorms to obviate: the 
production of hail. 
ing unaccompanied with any detail rela- 
tive to the procefs, and even the name of 
the diftricts where it is practised, and the’ 
execution of the methods propofed by M. 
Denize appearing to the Academy to be 
attended with too great difficulties, this 
Memoir, in which all the phenomena ana- 
Jogous to the fubject are prefented with 
great peifpicuity, and explained accerd- 
ing to the principles of fuund philofo- 
yhy, excited much interef, but did ‘net 
oviain that degree of attention which it ap- 
peais to me to deferve. 
I learned by accident, a very fhort time. 
ince, that the procefs to which M. Denize 
alludes is employed in moft of the com- 
munes of the ci-devant Magonnais, and 
that part of the mining powder which IL 
fend into that canton of the department of 
Ss6ne and Loire is ufed for the purpole of 
difipating ftorms and pyeventing hail. 
The defire of afcertaining fuch an inte. 
refting fadt led me to avail mylelf of my 
connection with that department to pro- 
cure circumftantial details concerning the 
procé{s, and its analogy with the princi- 
ples eftablifned in the Memoir of M. De- 
nize; andthe confequences that writer de- 
Guces from it made me defirous to perufe 
his Memoir again, and to examine the va- 
ricus means propofed by_the author for 
checking the calamity at tts fource. 
I fhall add a fact which has convine:d 
me of the influence cf violent and repeated 
explofions on thtck clouds. I had an op- 
portunity of making this obfervation my- 
felf at Grenoble, where a School of Ar- 
tilery is eftablifhed. % 
_ TYhe tky was pure and ferene, when, 
about nine o’clock in the morning, nume, 
rcus clouds extended themfelves over the 
whoie valley in which Grenoble is fiiuated, 
and covered the mountains that bound it. 
Scarcely bad the artillery-exercifes begun, 
between nine and ten, when the clouds. 
difperied above the Polygon, and made 
place fur the mott beautiful azure: ner 
was that part again cvercad till the exer- 
ciles were concluded, ae ig 
The Memoir then proceeds to flate, that , 
the only prefervative againft hail which 
natural philofophers have yet indicated is 
the efablifhment of 
ecnduétors. 
g vt ” ” Before | 
This mdication bes - 
~~ 
numerous electric | 
