338 Crystallization of Snow. 
On the 16th of March, (1819) at 5 o’clock P. M.I had 
the pleasure of observing the beautiful asteroidal figures 
sometimes assumed by flakes of snow. On examination 
each appeared to be compesed of six thin spicule, diverging 
like rays from a centre. ere was but little or no wind, 
and Farenheit’s thermometer stood at 33°. The figures 
which I observed are exhibited in the plate at the end of 
the volume, and the numbers annexed to them corrrespond 
with those in the following description. 7 
No. 1. This is a simple hexagonal star, the radii were of 
equal lengths and the angles of convergence being equal, 
each angle was of course 60°. 
No. 2. This crystal differs from No. 1, only in the length 
and breadth of the spicule, they were shorter and broader. 
o. 3. A simple star, except that the radii proceed 
from a central knob. 
No. 4. The same as the last, differing from it only in 
having the radii bifurcated at the end. 
o. 5. Differing from No. 4 in having three prongs at 
the extremity of the radii. 
No. 6. The radii pinnated near the centre, giving the ap- 
pearance of regular hexagonal figures one within the other, 
about half the distance between the pinne and the ex- 
tremity of each radius there was a knob. 
No. 7. Pinnated as No. 6, but without the knob, and 
having each radius trifurcated at the end. 
e snow commenced falling, the above figures 
were more distinct and durable, but they could occasionally 
be discovered for about an hour amid the amorphous flocculi. 
Just as the crystals No. 6 and 7 began to melt, their pinna- 
ted radii were most brilliant, assuming somewhat the ap- 
pearance of prismatic drops of dew. ‘The figures were not 
ll of the same dimensions ; their principal difference was 
similar to that stated in Nos. 1 and 2. These figures were 
examined both with the single microscope and the naked 
eye ; when not pinnated they were viewed with the most 
satisfaction without using a glass. 
M. De Rattee, who has published an interesting article om 
this subject in the French Encyclopeedia, states, that regu- 
lar crystals of snow do not often occur, but that the flakes 
are commonly of an irregular and unequal figure. He also 
