| | | | | 0.2 | | 0°.4 | | | | | 11°.8 | | 58°.5 | | |30° 2′ | |Cairo | 17°.7 ----- | | 71°.8 ----- | | | | | | 23°.4 | | 84°.7 | | +---------+------------+----------+------------------------+-----------------------+ In the column of temperatures in the preceding table the first number represents the temperature of the year; that which stands in place of a numerator the mean winter temperature; and that which stands in the place of a denominator the mean summer temperature. Besides the great difference of mean annual temperature, there is also a striking difference between the two coasts in respect to the distribution of that temperature into the different seasons of the year, and it is this distribution which is most influential both on our feelings and on the processes of vegetation. Dove remarks generally, that the summer temperature of America is lower under equal degrees of latitude than that of Europe: (Temperatur tafeln nebst Bemerkungen über die Verbreitung der Wärme auf der Oberfläche der Erde, 1848, S. 95.) The climate of St. Petersburgh, (or to speak more correctly the mean annual temperature of that city which is in lat. 59° 56′), is found on the east coast of America in lat. 47-1/2°, or 12-1/2° more to the south; in like manner we find the climate of Konigsberg, (lat. 54° 43′), at Halifax, (lat. 44° 39′). The temperature of Toulouse, (lat. 43° 36′) corresponds to that of Washington (lat. 38° 53′). It would be very hazardous to lay down any general statements respecting the temperature in the territory of the United States of America, as we must distinguish in that territory three regions:--1, the Atlantic States east of the Alleghanies; 2, the Western States in the wide basin between the Alleghanies and the Rocky Mountains, through which flow the Mississipi, the Ohio, the Arkansas, and the Missouri; 3, the high plains between the Rocky Mountains, and the Maritime Alps of New California through which the Oregon or Columbia River finds a passage. Since the highly honourable establishment, by John Calhoun, of uninterrupted observations of temperature, made on an uniform plan at 35 military posts, and reduced to daily, monthly, and annual means, we have arrived at more just climatic views than those which were so generally received in the time of Jefferson, Barton, and Volney. These meteorological stations or observatories extend from the point of Florida and Thompson’s Island, (Key West), lat. 24° 33′, to the Council Bluffs on the Missouri; and if we reckon amongst them Fort Vancouver, lat. 45° 37′, they include differences of longitude of 40°.