It is evident that places may have the same mean annual temperature, and yet differ materially in climate. In one, the winters may be mild and the summers cool; whereas another may experience the extremes of heat and cold. Lines passing through places having the same mean summer or winter temperature are neither parallel to the isothermal, the geothermal lines, nor to one another, and they differ still more from the parallels of latitude. In Europe, the latitude of two places which have the same annual heat never differs more than 8° or 9°; whereas the difference in the latitude of those having the same mean winter temperature is sometimes as much as 18° or 19°. At Kasan, in the interior of Russia, in latitude 55°·48, nearly the same with that of Edinburgh, the mean annual temperature is about 37°·6; at Edinburgh it is 47°·84. At Kasan the mean summer temperature is 64°·84, and that of winter 2°·12; whereas at Edinburgh the mean summer temperature is 58°·28, and that of winter 38°·66. Whence it appears that the difference of winter temperature is much greater than that of summer. At Quebec the summers are as warm as those in Paris, and grapes sometimes ripen in the open air: whereas the winters are as severe as in Petersburgh; the snow lies five feet deep for several months, wheel carriages cannot be used, the ice is too hard for skating, travelling is performed in sledges, and frequently on the ice of the river St. Lawrence. The cold at Melville Island on the 15th of January, 1820, according to Sir Edward Parry, was 55° below the zero of Fahrenheit’s thermometer; and when Dr. Kane was on the northern coast of Greenland it was 70° below that point; yet the summer heat during the day in these high latitudes is insupportable.