alf. March 26-27, 1818, the
thermometer in St. Louis, fell 41 deg. in 30 hours--from 83 deg. to 42
deg. I have no record or recollection of a more sudden change in 18
years. Mr. Legaux saw it fall in the vicinity of Philadelphia, 47 deg. in
24 hours, and Dr. Drake states that this is five degrees more than any
impression ever observed in Cincinnati, in the same length of time.
Emigrants from New England and the northern part of New York state, must
not expect to find the same climate in the West, at 38 or 40 degrees; but
let them remove to the same parallel of latitude in the West, to
Wisconsin, or the northern part of Illinois, and they will probably find
a climate far more uniform than the land of their birth.

Prevailing winds modify and affect the climate of every country.
Southwestwardly winds prevail along the Mississippi Valley. The
following tabular view of observations made at Cincinnati, by Dr. D.
Drake, for six succeeding years, with so few omissions, that they amount
to 4200, will give further illustrations of this subject. They have been
brought from eight points of the compass.

OBSERVATIONS.

MONTHS | S.E. | S. | S.W. | N.E. | N. | N.W. | E. | W. | CALM.
===========+======+====+======+======+====+======+====+====+=======
January | 6 | 2 | 13 | 8 | 1 | 21 | 3 | 6 | 6
February | 5 | 1 | 13 | 8 | 1 | 14 | 0 | 5 | 8
March | 10 | 1 | 16 | 11 | 1 | 10 | 0 | 5 | 4
April | 7 | 0 | 24 | 10 | 1 | 8 | 1 | 3 | 5
May | 7 | 1 | 19 | 10 | 0 | 10 | 1 | 4 | 6
June | 9 | 1 | 23 | 12 | 5 | 7 | 1 | 2 | 3
July | 6 | 1 | 19 | 11 | 2 | 11 | 1 | 4 | 4
August | 6 | 1 | 23 | 10 | 1 | 12 | 1 | 1 | 6
September | 6 | 1 | 23 | 9 | 0 | 8 | 2 | 3 | 3
October | 9 | 1 | 24 | 6 | 1 | 10 | 2 | 4 | 3
November | 9 | 3 | 13 | 6 | 1 | 10 | 2 | 7 | 5
December | 7 | 1 | 11 | 5 | 0 | 15 | 2 | 6 | 9
-----------+------+----+------+------+----+------+----+----+-------
Total | 87 | 14 | 221 | 106 | 14 | 136 | 16 | 50 | 62

The results of my own observations, made for twelve years, with the
exception of 1826, and with some irregularity, from travelling in
different parts of Missouri and Illinois during the time, do not vary in
any material degree from the above table, excepting fewer e