Crystalhzation of Snow. 339 
remarks it is worthy of observation that the different sorts of 
erystals are scarcely ever seen during the same fall of 
snow, the varieties appearing at different hours of the day 
or on different days. [am of opinion they occur more fre- 
quently than is here supposed, and that different crystals 
are seen during the same fall of snow. We have besides 
the instance now noticed, the authority of Dr. John Netts, 
who has published a paper in the 49th Vol. (1756) of the 
Philosophical Transactions, entitled “ an account of a meth- 
od of, observing the wonderful configurations of the smallest 
shinng particles of snow.” In one day and night (he ob- 
serves) | found fifteen, twenty or more particles of snow dii- 
ferently formed, such as Olaus Magnus mentions, and in the 
year 1740, on the 11th, 12th, 13th, 21st and 23d of January, 
and also on the 6th, 23d and 24th of February, I had an op- 
portunity of delineating eighty different admirable figures of 
snow, and of observing their numberless varieties. 
Accompanying this | paper there are figures of ninety-one 
of these beautiful configurations ; the size of them is much 
- less than those observed by me on the 16th of March, and 
as they were examined with a double microscope, greater 
complexity was noticed. Most of Dr. Netts’ figures are 
hexagonal, but some of the stars exhibited twelve radii. 
In April 1817, Dr. P. S. Townsend read before the Ly- 
ceum of Natural History of New-York, a very interesting 
memoir on the crystallization of snow. In this paper the 
Doctor has collected most of the facts known respecting this 
subject, and has referred to the writers who have considered. 
it. His communication was published in the American 
Monthly Magazine for May, 1818. 
Sometime since an account of stellar snow was forwarded 
tous by Dr. Jacob Porter of Plainfield ; it was described 
as being “in the most regular and beautiful crystals, each 
crystal consisting of six rays diverging from a common cen- 
tre, and each ray of a number of inferior rays proceeding 
from it ina pinnate form.” ‘The forms observed by Dr. 
Porter will be found among those delineated by Professor 
Green.—[ Ep. | 
