Page:Physical Geography of the Sea and its Meteorology.djvu/321

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THE GEOLOGICAL AGENCY OF THE WINDS.
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as sharply defined in nature as the lines suggested, or as Plate VII. would represent them to be.

545. Their situation, and the range of dry minds.—The whole region of the extra-tropical Old World that is included within the ranges marked is the region which has most land to windward of it in the southern hemisphere. Now it is a curious coincidence, at least, that all the great extra-tropical deserts of the earth, with those regions in Europe and Asia which have the least amount of precipitation upon them, should lie within this range. That they are situated under the lee of the southern continents, and have but little rain, may be a coincidence, I admit; but that these deserts of the Old World are placed where they are is no coincidence—no accident: they are placed where they are, and as they are, by design; and in being so placed, it was intended that they should subserve some grand purpose in the terrestrial economy. Let us see, therefore, if we can discover any other marks of that design—any of the purposes to be subserved by such an arrangement—and trace any connection between that arrangement and the supposition which I maintain as to the place where the winds that blow over these regions derive their vapours. It will be remarked ,at once that all the inland seas of Asia, and all those of Europe except the semi-fresh-water gulfs of the north, are within this range. The Persian Gulf and the Red Sea, the Mediterranean, the Black, and the Caspian, all fall within it. And why are they planted there? Why are they arranged to the north-east and south-west under this lee, and in the very direction in which theory makes this breadth of thirsty winds to prevail? Clearly and obviously, one of the purposes in the divine economy was, that they might replenish with vapour the winds that are almost vapourless when they arrive at these regions in the general system of circulation. And why should these winds be almost vapourless? They are almost vapourless because their route, in the general system of circulation, is such, that they are not brought into contact with a water-surface from which the needful supplies of vapour are to be had; or, being obtained, the supplies have since been taken away by the cool tops of mountain ranges over which these winds have had to pass.

546. The Mediterranean within it.—In the Mediterranean, the evaporation is greater than the precipitation. Upon the Red Sea there never falls a drop of rain; it is all evaporation. Are