It is true that a low summer temperature is the normal state of matters in very high latitudes, but it is so only in consequence of the perpetual presence of snow and ice. When we speak of the normal temperature of a place we mean, of course, as we have already seen, the normal temperature under the present condition of things. But were the ice removed from those regions, our present Tables of normal summer temperature would be valueless. These Tables give us the normal June temperature while the ice remains, but they do not afford us the least idea as to what that temperature would be were the ice removed. The mere removal of the ice, all things else remaining the same, would raise the summer temperature enormously. The actual June temperature of Melville Island, for example, is 37°, and Port Franklin, Nova Zembla, 36°·5; but were the ice removed from the arctic regions, we should then find that the summer temperature of those places would be about as high as that of England. This will be evident from the following considerations:— The temperature of a place, other things being equal, is proportionate to the quantity of heat received from the sun. If Greenland receives per given surface as much heat from the sun as England, its temperature ought to be as high as that of England. Now, from May 10 till August 3, a period of eighty-five days, the quantity of heat received from the sun in consequence of his remaining above the horizon is actually greater at the north pole than at the equator. Column II. of the following Table, calculated by Mr. Meech,[43] represents the quantity of heat received from the sun on the 15th of June at every 10° of latitude. To simplify the Table, I have taken 100 as the unit quantity received at the equator on that day instead of the unit adopted by Mr. Meech:— +-----------+---------+-----------+-------------+ | | I. | II. | III. | | | | | | | |Latitude.| Quantity | June | | | | of heat. | temperature.| +-----------+---------+-----------+-------------+ | | ° | | ° | |Equator | 0 | 100 | 80·0 | | | 10 | 111 | 81·1 | | | 20 | 118 | 81·1 | | | 30 | 123 | 77·3 | | | 40 | 125 | 68·0 | | | 50 | 125 | 58·8 | | | 60 | 123 | 51·4 | | | 70 | 127 | 39·2 | | | 80 | 133 | 30·2 | |North Pole | 90 | 136 | 27·4 | +-----------+---------+-----------+-------------+