12 E. Loomis—Results from an examination of the 
time fell from +16° to —22°. At Jakutsk, in Siberia, lat. 62°, 
the mean temperature of January is —44° Fahr. But on the 
21st of January, 1838, the thermometer fell to —76? F:, of 
32° below the mean temperature of the season. Now accord- 
ing to Dove's charts, there is no place on the earth’s surface 
where the mean temperature of the coldest month is much be- 
low that of Jakutsk. What can cause such an extreme de- 
pression of the thermometer at the coldest point of the earth’s 
surface? I think we are shut up to the conclusion that this 
more remarkable than their magnitude. On the 21st of Decem- 
ber, 1836, the thermometer at Albany fell 18° in one hour, 
. 
from 11 A. M. to noon. Allowing for the usual diurnal change 
ture of 20° in one hour, being the effect of a severe storm then 
in progress. In summer, during a thunder shower, it is not 
unusual for the thermometer to fall 5° or even 10° in a few 
minutes. Now an examination of the weather maps will show 
latitude, with, however, a slight inclination northward, that is, 
rom a warmer to a colder region. These sudden gusts of cold 
air are believed to descend from the upper regions of the atmos- 
h 
phere. 
Connection between the velocity of the wind and the distance be- 
ween the isobars in the neighborhood of a storm center. 
In order to determine the connection between the velocity of 
the wind and the distance between the isobars, I ruled a large 
sheet of paper with 40 vertical columns, and placed at the head 
the columns the numbers 0, 1, 2, 3, etc.. to denote velocit 
of the wind. Each weather map was then examined for ob- 
servations suited to the present object. In the selection of sta- 
tions the following rules were adopted: 1, All the observations 
influence of another storm center that observation was rejected. 
All the observations made on Mt. ashington .were rejected. 
For each station which satisfied the above conditions the per- 
pendicular distance between the two adjacent isobars was 
