1806. } 
ftones. If they have a volcanic origin, 
being all nearly fimilar in their compo- 
nent parts, we mult fuppofe that they 
have been ejected from one particular vol- 
¢ano; but what muft be the projeétile 
force, to throw from it a ftone either to 
Benares in the Eaft Indies, or to York- 
fhire. 
The iogenious Mr. Sowerby thinks we 
may find rocks in Britain fimilar to thefe 
ftones; and that the eleétric fluid, attraét- 
ed by the iron, might detach a fragment 
or fragments of the rock, and produce 
an explofion and flame.—See Britifh Mi- 
neralogy, No. 29. 
Of the different explanations of the 
phenomenon, it appears to me the leaft 
improbable to fuppofe that thefe ftones 
are thrown from a volcano in the moon; 
and there isa fiagular circumftance ob- 
ferved to precede the fall of a meteoric 
ftone, that may be explained on this hy- 
pothefis.—It has been remarked, that a 
body proje&ted from the moon with a 
velocity about three times greater than 
that of a cannon-ball, would infallibly 
reach the earth. But the mountains 
of the moon appear by obfervation far 
higher than thofe on our earth, the 
force, therefore, might even be’ lefs 
than this afligned. Let us fuppofe a 
ftone, highly heated, thrown from a lunar 
voleano, reaches the attraction of the 
earth; after pafling the moon's atmo- 
{phere, and till it reached that of the 
earth, it is difficult to imagine, accord- 
ing tothe laws of heat, that it could cool. 
The upper ftratum of our atmofphere is 
fuppofed to confit of hydrogen: the 
heated ftone would pafs through without 
fiting it, as the hydrogen will not burn 
without oxygen; but where the hydrogen 
and atmofpheric air unite and mingle, an 
explofion would take place, and the ftone 
might acquire fo much more heat as to be- 
come highly red-hot, and have the ap- 
pearance of a fiery meteor. If the quan- 
tity of air and hydrogen exploded was 
greater on cne fide of the ftone than on 
the oppofite fide, the flone might take an 
oblique direétion in its fall. 
_ confidered unphilofophical to menticn the 
moon’s atmofphere : but if we admit that 
there are volcanocs in the moon, how can 
we rejeét an atmolphere? A vo'cano mutt 
originate from fume elaftic fluid, and an 
elaitic fluid forms an atmofphere. 
GOL 
P.S. The noble family of Glencairn hes 
lately become extin€&, and it is in vain to 
inquire if the ftone be fill preferved. 
s 
Nitrous or Vitriolic Acid.—AZir Ballions, - 523 
It will be. 
To the Editor of the Monthly Magazine. 
SIR; 
ah any of your correfpondents could 
inform me, through the medium 
of your mifceilany, what will deprive 
the nitrous or vitriolic acid of its cor- 
rofive quality, when acting upon lea- 
ther, yet not to fuch a degree as to dif- 
qualify it for being a menftruum for ftains, 
he would much oblige Your’s, &c. 
ARTIST. 
a 
To the Editor of the Monthly Magazine. 
SIR, 
HE utility of air-balloons may be 
dcubted ; but as they are fometimes 
ufed, to add to their fafety may be defir- 
able. Inftead of the gas being confined 
in one grand globe, 1 propofe that the 
balloon be divided into chambers, one or 
two of which would float it in the air, or, 
at leaft, prevent its falling to the earth 
with a precipitancy dangerous to the ad- 
venturers, This principle, perhaps, may 
lead to further improvements. R.S. 
—a 
For the Monthly Magazine. 
OBSERVATIONS on. a PROCESS employed 
in the ci-devant MAGONNAIS, to prewent 
HAIL and difipate STORMS; by M. 
LESCHEVIN, CHIEF COMMISSARY of 
GUNPOWDER @zd SALTPETRE @f DI- 
JON. : 
the is upwards of five-and twenty years, 
fince the confideration of the miichicfs ~ 
occafioned by ftorms, accompanied with 
hail, induced feveral men of {cience and 
friends of humanity to endeavour to dif- 
cover means capable of preventing this de- 
flructive calamity. M. Gueraut de 
Montbeillard, the celebrated affitant of 
Buffon, being led by the cblervation that 
hail is formed only after violent claps of 
thunder, to fuppoie that lightning con- 
tributes much towards its formation, pro- 
pofed, in 1776, the ere&tion of numerous 
conductors, which, by drawing of the 
electric matter, would prevent the explo- 
fion of the lightning, and confequently the 
formation of hail. His Memoir, in the 
form of a letter to M. Guyton de Mor- 
veau, was read to the Academy of Dijon, 
and was inferted in the twenty-firft vo. 
Jume of the Journal de Phyfique. In fup- 
port of his opinion on the caufes of hail, 
M. de Montbeillard adduces the obferva- 
tions of the moft eminent natural philofo- 
pbers, and. propofes phyfical and econo- 
mical means of execution, 
This 
