Page:Physical Geography of the Sea and its Meteorology.djvu/33

Rh latent form with the vapours from the southern seas;—2. by the transfer of heat in the sensible form, by currents such as the Gulf Stream, et al., from one climate to another in our hemisphere. Hence we infer that the southern hemisphere is in certain zones cooler than the northern, not by reason of its short summer or long winter, but it is the cooler chiefly on account of the latent heat which is brought thence by vapour, and set free here by condensation.

21. England about the pole of hemisphere with most land.—Within the torrid zone the land is nearly equally divided north and south of the equator, the proportion being as 5 to 4. In the temperate zones, however, the north with its land is thirteen times in excess of the south. Indeed, such is the inequality in the distribution of land over the surface of the globe that the world may be divided into hemispheres consisting, the one with almost all the land in it, except Australia and a slip of America lying south of a line drawn from the desert of Atacama to Uruguay; England is the centre of this, the dry hemisphere. The other, or aqueous hemisphere, contains all the great waters except the Atlantic Ocean; New Zealand is the nearest land to its centre.

22. Effects of inequality in distribution of land and water.—This unequal distribution of land, light, air, and water is suggestive. To it we owe, in a measure, the different climates of the earth. Were it different, they would be different also; were it not for the winds, the vapours that rise from the sea would from the clouds be returned in showers back to the places in the sea whence they came; on an earth where no winds blow we should have neither green pastures, still waters, nor running brooks to beautify the landscape. Were there no currents in the sea, nor vertical movements in the air, the seasons might change, but climates would be a simple affair, depending solely on the declination of the sun in the sky.

23. Quantity of fresh water in American lakes.—About two-thirds of all the fresh water on the surface of the earth is contained in the great American lakes; and though there be in the northern, as compared with the southern hemisphere, so much less sea surface to yield vapour, so much more land to swallow up rain, and so many more plants to drink it in, yet the fresh-water courses are far more numerous and copious on the north than they are on the south side of the equator.