88 
In Switzerland, the wind observations are taken by the 
anemometer placed near the meteorological station. Now 
many of these are in the valleys, and as the valley winds 
are so frequently merely local, these observations have little 
value for our purpose, and the same may be said for general 
meteorological purposes. On January 9th, when some of 
the crystals were observed, the wind registered in the valley 
at the meteorological station was north, while the clouds, 
which I always noticed for my observations, showed that a 
south wind was blowing above. 
I have called attention to the fact that I did not find the 
classification of Scoresby^' always corresponded with what I 
observed ; finding sometimes low temperature forms on the 
coldest days. This may probably be explained by the fact 
that in the arctic regions there are fewer counter currents, 
and so the crystals were formed under more uniform circum- 
stances ; yet at the same time the only explanation of the 
variety exhibited in each crystal must arise from growth 
taking place under slightly altered circumstances, or else 
why should it suddenly change from one type to another ? 
The amount of wind seems to exert quite as much infiu- 
ence upon the form of the crystal as does the temperature. 
When there is little motion of the air the crystal can go on 
building itself up regularly in all six directions ; but with a 
considerable amount of wind the conditions for this building 
up are more favourable on one side than another, so that 
we may get showers of acicular snow when a strong wind 
prevails. On the same principle the one side of a rope may 
be covered with hoar frost turning in the direction of the 
wind, but the same thing can sometimes be still better seen 
on a fir, all the leaves of which are covered with acicular 
hoar frost ; these needles in the same way all having a direc- 
tion against the wind. 
The temperature when the crystal figured fell was be- 
tween — 10*5 C. and 
* Voyage to Grreenland, 1823« 
