In Pennsylvania, the range of the mercury in Fahrenheit’s thermometer has been observed to be from 24° below cipher to 105° above it; but it is an unusual occurrence for the mercury to stand at either of these extreme points; in its approach towards them it commonly draws much nearer to the extreme of heat than to that of cold. During the winter of 1795, and the three preceding years, it did not sink lower than 10° above cipher; a summer however seldom passes over that it does not rise to 96°. It was mentioned as a singular circumstance, that in 1789 the thermometer never rose higher than 90°. [Sidenote: CLIMATE.] Of the oppression that is felt from the summer heats in America, no accurate idea can be formed without knowing the exact state of the hygrometer as well as the height of the thermometer. The moisture of the air varies very much in different parts of the country; it also varies in all parts with the winds; and it is surprising to find what a much greater degree of heat can be borne without inconvenience when the air is dry than when it is moist. In New England, in a remarkably dry air, the heat is not found more insupportable when the thermometer stands at 100°, than it is in the lower parts of the southern states, where the air is moist, when the thermometer stands perhaps at 90°, that is, supposing the wind to be in the same quarter in both places. In speaking of Virginia I have taken notice of the great difference that is found between the climate of the mountains and the climate of the low country in that state. The case is the same in every other part of the country. From the mountains in New England, along the different ridges which run through New York, New Jersey, Pennsylvania, Maryland, and the southern states, even to the extremity of Georgia, the heat is never found very oppressive; whilst as far north as Pennsylvania and New York, the heat in the low parts of the country, between the mountains and the ocean, is frequently intolerable. [Sidenote: WEATHER.]