260 METEOEOLOGICAL OBSEKVATIONS. Book IT. 
During the last three days of August a hot south wind 
was blowing. In the night of the 1st of September signs 
of a change in the wind were perceptible : it lightened in 
the north under a cloudless sky, Towards morning there 
were broken clouds, and by noon the north wind set in : 
from that time we had several very cold nights. No dew 
had fallen during the south wind ; but as soon as the north 
wind set in, the grass was quite wet in the morning, and my 
feet became dreadfully benumbed with cold during my 
night-watch : the howling of the wolves also increased. 
Later on we were repeatedly exposed anew to a hot south 
wind, which caused illness among our people. I shall have 
occasion to notice the sudden change from this American 
sirocco to an icy north wind. 
