Page:Physical Geography of the Sea and its Meteorology.djvu/487

Rh annual precipitation at the rate of 577.6 inches during the six months of S.W. monsoons—from May to October. Surely no one will maintain that this vapour, after rising from the sea, reached the height of 4500 feet for the first time when it was blown upon the peaks of Cherraponjie. Islands in the South Sea are everlastingly cloud-capped. If it be mere refrigeration that condenses this vapour, why, one might ask, should not the clouds form at the same height above the sea whether there be an island below or not, and why should not these clouds precipitate as copiously upon the water, as they do upon the land? "We only know that they do not.

866. The climates of corresponding shores and latitudes north and south.—Captains King and Fitzroy exposed their rain gauge on the western slopes of the Patagonian Andes, and it collected 153.75 inches in forty-one days; that is, at the rate, as already (§ 827) stated, of 1368.7 inches in the year. The latent heat that is liberated during these rains gives to Eastern Patagonia its mild climate. It is this latent heat which causes the irregularity in the barometric curve (§ 858) between the parallels of 50°-55° S. Here the westerly winds prevail; they carry over to the eastern coasts the air that, in passing the mountains, is warmed by this liberated heat; and thus, as I have already (§ 729) endeavoured to show, we have an exception to the rule under which meteorologists ascribe cold and severe climates to the windward or western, soft and mild to the leeward or eastern, shores of extra-tropical oceans. Labrador and the Falkland Islands are in corresponding latitudes north and south. They are both on the windward shore of the Atlantic; they occupy relatively the same position with regard to the wind. Labrador is almost uninhabitable on account of the severity of its climate; but in the Falkland Islands and their neighbouring chores the cattle find pasturage throughout the winter. Th thermometrical difference of climate at these two places, north and south, may be taken as a sort of index to the relative difference between the arctic and antarctic climates of our planet.

867. Thermal difference between arctic and antarctic climates.—Along the eastern base of the Rocky Mountains the isotherms