* 
Meteorological Observations. 127 
Mean temperature for the year, 54° 93/, being, two and a half 
degrees more than in the year 1829. 
Rain and snow, 37 ,2,°; inches, being more than two inches less 
than in the preceding year. 
Prevailing winds, from the S. S. W. and N. N. W. 
eat the greatest in July, and least in January. 
We have had fifty-three fair days more than in the year 1829; 
this will explain the diminution in the quantity of rain. The season, 
after the 4th of July, haying been an uncommonly dry one—crops of 
Indian corn and potatoes suffering more from drought, than in any 
preceding year, since 1804: from the 4th of July to the 5th of Sep- 
tember, there fell but two and a half inches of rain, while the heat 
from the 5th of July to the last of August, ranged from 85° to 94°, 
mthe middle of the day, and the mean temperature for those two 
months was above 75° night and day. ‘The heat and drought ex- 
tended nearly or quite all over the Mississippi valley ; while at the 
sume time excessive rains were falling on the borders of the Green 
Mountains, and in the New England States. The spring months 
Were unusually fine: fruit trees were in blossom nearly twenty days 
earlier than in 1829, and all the spring crops ripe two or three weeks 
Sooner. Professor Olmsted’s theory of our climate is by far the 
Most plausible of any which I have seen, and his facts as to the prev- 
Nee of western winds over the United States, coincide with the 
observations made at this place. The general current of the atmos- 
Phere is from the west, setting round to the eastern quarter from the 
north, making a regular circuit in this manner, viz.— South-west, 
West, north-west, north, north-east, east, south-east and south ; but 
‘7ever in the opposite direction. ‘This series has been often observed 
m the vernal and autumnal months. The reader, in looking over 
© barometrical register, will doubtless be surprized at its low range. 
By Comparing it with a table kept at Lexington, (Ky.) and one in 
Athens, (Ohio) I find it is too low by about ;’, of an inch, proba- 
bly from there being a little air in the top of the tube. But from all 
"'@ observations I have seen, there is a difference of nearly an inch 
"the mean annual altitude of the mercury here, or that near the 
Atlantic shore. Ihave kept a table of atmospheric variations for 
three years, but have offered none for publication until now ; by 
Making the allowance above noted, it will vary but little from the true 
“Tate of the barometer in this part of the valley. 
