1817.) Scientific Intelligence. 169 
eolumn in about 24 hours was nearly equal to an inch of quicksilver. 
The temperature, from this time to the close, with a single excep- 
tion, was uniform, varying little by day or night, and a very gradual 
decrease of pressure from the first quarter of the new moon was 
followed by a heavy fall of rain. 
November.—Mean pressure of barometer, 29°562; max. 30°76; 
min. 28°35; range, 2°41 inches. Mean temperature, 37°480°; 
max. 50°; min. 23°; range, 27°. Mean of hyyrometer at nine, 
a.m. 704 nearly; snow and rain, 3°02 inches; wet days, 14; 
stormy, 6.—Prevailing wind, southerly. N., 2; E.,1; N.E. 2; 
oa ie Wat, 25 54 95 Wb s S2W555'N.W., 3. 
The changes in the pressure and temperature of the atmosphere 
during the former part of this period were so rapid and consider- 
able, particularly in the former, as to be almost without precedent. 
The gradual depression of the barometrical column which marked 
the close of the last month continued with much rain until the 4th, 
when a brisk wind from the N.E. caused it to rise nearly half an 
inch. The next day, when the moon attained her full, a very 
sudden depression of eight tenths took place in a few hours, and 
was followed by a heavy storm of wind and rain from the north. 
The Sth was frosty and clear until sun-set, with the column steady, 
but very soon afterwards the clouds assumed their wintry appear- 
ance, and much snow fell, with the wind at S.W. until ten, when, 
it having veered to the southward, the weather became most tem- 
pestuous, with continued heavy rain, until seven the next morning. 
The barometer during the night fell from 29°35 to 28:45; but the 
air now clearing up, and the wind N.W., this loss was regained in 
about six hours. ‘The 10th, like the 8th, was clear and frosty until 
three, p.m. when abundance of linear Cirrt appeared, and began 
to extend in all directions, followed by the Cirrostratus. The wind 
went from N.W. by W. to the S., and (if possible) a more tem- 
pestuous night than that of the 8th was experienced, with much 
snow andrain. ‘The loss of quicksilver during the day, from eight, 
a.m. to eleven, p.m. was equal to a full inch; but the storm 
having then a little abated in its violence, this quantity (with an 
increase of nearly half an inch) was almost as rapidly restored. 
Snow fell daily from this time to the 18th, attended on the 14th 
with a violent gale from the S., and incessant vivid lightning and 
Joud thunder for nearly three hours in the S., W., and S.W. The 
weather on the 20th became more settled; and continued calm and 
frosty, with little variation, to the close of the month. On the last 
day the barometer, which for six preceding days had gradually been 
rising, remained stationary at 30°76, the maximum of the period. 
December.—Mean pressure of barometer, 29°495: max. 30°76; 
min. 27°90! range, 2°86 inches. Spaces described, 15°87 inches. 
Number of changes, 23. Mean temperature, 34°382°; max. 48°; 
min. 16°; range, 32°. Mean of de Luc’s hygrometer at nine, 
a.m. 76}.—Prevailing winds, W. and S.W. N., 3; 8.6, 1; 
