esults, 53 deg. and
a third, is but the fraction of a degree lower than the mean heat of
Cincinnati, and actually less than should be afforded by the difference
of latitude.

"A reference to the temperatures of summer and winter, will give nearly
the same results. From nine years' observations, (three at Spring Mill,
by Mr. Legaux, and six in Philadelphia, by Dr. Coxe,) the mean summer
heat of that part of Pennsylvania, appears to be 76 degrees and
six-tenths. The mean summer heat at Cincinnati, for an equal number of
years, was 74 degrees and four-tenths. The average number of days in
which the thermometer rose to 90 degrees or upwards, during the same
period, was fourteen each summer; and the greatest elevation observed
was 98 degrees: all of which would bear an almost exact comparison with
similar observations in Pennsylvania. Mr. Legaux states the most intense
cold, at Spring Mill, from 1787 to 1806, to have been 17 and
five-tenths degrees below cipher,--while within the same period it was
18 deg. at Cincinnati. The average of extreme cold for several years, as
observed by Mr. Legaux, was one and eight-tenths of a degree below
cipher:--the same average at Cincinnati, was two degrees below. From all
which we may conclude, that the banks of the Delaware and Ohio, in the
same latitudes, have nearly the same temperature."

The state of Illinois, extending as it does through five and a half
degrees of latitude, has considerable variation in its climate. It has
no mountains, and though undulating, it cannot be called hilly. Its
extensive prairies, and level surface, give greater scope to the winds,
especially in winter. In the southern part of the State, during the
three winter months, snow frequently falls, but seldom lies long. In the
northern part, the winters are as cold, but not so much snow falls, as
in the same latitudes in the Atlantic States.

The Mississippi at St. Louis is frequently frozen over, and is crossed
on the ice, and occasionally for several weeks. The hot season is
longer, though not more intense, than occasionally for a day or two in
New England.

During the years 1817-18-19, the Rev. Mr. Giddings, at St. Louis, made a
series of observations upon Fahrenheit's thermometer.

Deg. Hund.
Mean temperature for 1817 55 52
Do. do. from the beginning
of May, 1818, to the end
of April, 1819