On the Formation of Hail. 97 
for the relief of the inhabitants of a little village, who had been 
entirely ruined by the destructive ravages occasioned by hail 
showers. 
Instead of concurring with the common theory in supposing 
that the less dense exterior coating of the hail-stones (‘ resem- 
bling the surface of a vessel containing a freezing mixture’’) is 
formed by adhesions in their descent through a warmer stratum 
of air than that in which the nuclei were generated, I have attri- 
buted it, in my theory, to the increase of cold, by which the par- 
ticles of vapour are frozen before they adhere to their respective 
nuclei, when in consequence of the attractive power, exerted 
upon the frozen particles of vapour by the nuclei, not being suffi- 
cient to make them cohere as closely as if ina fluid state, the 
exterior coating must, agreeable to observation, be of a less dense 
nature. Though drops of rain are liable to sudden accessions by 
running into each other, the influence of the electric fluid is suffi- 
ciently obvious in thunder showers, by the uniform magnitude of 
the drops: why its influence in hail showers, which seldom oc- 
cur unaccompanied by thunder and lightning, should be doubted, 
I cannot conceive, for certainly there is nothing in the appear- 
ance of the stones which opposes the probability of their elec- 
trical formation, and it is the only way in which their size can 
be reasonably accounted for. 
The circumstance of hail being usually accompanied by thun-. 
der and lightning, is not allowed in the Cyclopedia to be a proof 
that the superabundance of electric fluid operates in its forma- 
tion, but that thunder happens when the atmosphere is most re- 
plete with vapour, which is also favourable to the generation of 
hail. 
I have already observed in my theory, that I conceived the 
degree of humidity of the atmosphere would operate as one cause 
in regulating the size of the hail-stones; but as the electric fluid 
is inactive in the higher latitudes where hail is unknown, though 
there is no want of vapour to produce rain and snow, | think it 
appears evident, that ‘ hail is the attendant on thunder,’’ be- 
cause it owes its origin to electricity. 
XXI. True apparent Right Ascension of Dr. MaskELYNE’s 36 
Stars for every Day in the Year 1822, at the Time of passing 
the Meridian of Greenwich. By the Rev. J. Groosy. 
The mean Right Ascensions are taken from Mr.Pond’s Catalogue. 
in the Nautical Almanac for 1828, and the Corrections from 
the Tables of M. Bessel. On those days where an asterisk is 
prefixed the Star passes twice, the AR there given is that at 
the first passage. 
Vol. 59, No, 286, Fel. 1822, a 1822. 
