100 
For, the earth possesses a wonderfully retentive power, only parting with 
its heat in the most gradual manner, which is proved by the following ex¬ 
periments of the illustrious Dr. Hales. 
EXPERIMENT I. 
This philosopher having observed that the air was at 88° of Farhenheifs 
thermometer, August 1, ! ?24, found that the earth at its surface had pre¬ 
cisely the same heat; the thermometer being then plunged two inches deep 
into the ground, stood at 85°; another at sixteen inches, at 70 °; and another 
at twenty-four inches, at 6 8°. 
The two last preserved the same temperature day and night to the end 
of the month, and then only fell to f)3°. 
EXPERIMENT IF 
On the 26 th of October, a thermometer exposed to the air by the same 
philosopher stood at 35° 5; but one sunk two inches in the earth was found 
to rise to 43° 85, another sunk sixteen inches reached 48° 8, and one at 
twenty-four inches stood at 50°. 
EXPERIMENT III. 
He even found, that between the first and second of November, when 
the external air was at 2f°, a thermometer at twenty-four inches depth stood 
at 43° 8. 
EXPERIMENT IV. 
When, in the coldest days of the winter 1/24, the frost was so intense 
as to freeze the surface of stagnant water near an inch thick, Dr. Hales re¬ 
marked, that his thermometer, which was exposed to the open air, was four 
degrees below the freezing point; and he found that placed two inches under 
ground it was four degrees above the freezing point; the third, fourth, and 
fifth thermometers were proportionably higher, as they were deeper in the 
ground, to the sixth thermometer, which being two feet under ground the 
spirit was as high as ten degrees above the freezing point. 
