I believe* thefe may be confidered to be nearly the extremes of heat and cold in that part of the country. The latter may moft certainly, as at that time, York river, at York town, was frozen over, fo that people walked acrofs it; a circumftance which proves it to have been colder than * At Paris, in 1753, the mercury in Reaumur's thermometer was at 30 i-z above o, and in 1776, it was at 16 below o. The extremities of heat and cold therefore at Paris, are greater than at Williamfburgh, which is in the hotteft part of Virginia.
the winter of 1740, 1741, ufually called the cold winter, when York river did not freeze over at that place. In the fame feafon of 1780, Chefapeak bay was folid, from its head to the mouth of Patowmac.
At Annapolis, where it is §i miles over between the neareft points of land, the ice was from 5 to 7 inches thick quite acrofs, fo that loaded carriages went over on it. Thofe, our extremes of heat and cold, of 6^ and 9 8" were indeed very diftreffing to us, and were thought to put the extent of the human conftitution to confiderable trial. Yet a Siberian would would have confidered them as fcarcely a fenfible variation. At Jennifeitz in that country, in latitude 58"" 27^ we are told, that the cold in 1735 funk the mercury by Farenheits fcale to 126^ below nothing;
and the inhabitants of the fame country ufe ftove rooms two or three times a week, in which they flay two hours at a time, the atmofphere of which raifes the mer- cury to 135^ above nothing. Late ex- periments fhow that the human body will exift in rooms heated to 140'' of ReauX t 154 ] niur, equal to 347^ of Farenheit's, and 135^ above boiling water. The hotteft point of the 24 hours is about four o'clock, P. M. and the dawn of day the coldeft.
The accefs of froft in autumn, and its recefs the fpring, do not feem to depend merely on the degree of cold ; much lefs on the air's being at the freezing point* White frofts are frequent when the ther- mometer is at 47^