Page:Popular Science Monthly Volume 8.djvu/722

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echinoderms, mollusks, and crustaceans. The observations of these educated naturalists are familiar to the readers of the "Transactions" of the German zoological societies. For a long time the discoveries of this large party of expert collectors were thus freely contributed to the various scientific publications of Germany and Great Britain, But in 1873 Herr Godeffroy commenced the Journal of the Museum Godeffroy, a thick quarto issued in four yearly parts. This journal contains the elaborate report of distinguished naturalists on the series of specimens submitted to them. Thus Milne Edwards, of the Garden of Plants at Paris, has described the crustaceans; and Lütken, of Copenhagen University, the echinoderms; and Dr. Günther, the celebrated ichthyologist of the British Museum, the fishes. The Journal is profusely illustrated with colored cuts, and takes high rank for its beauty and scientific value.

Such is the remarkable Museum Godeffroy. As a storehouse of material for the benefit of working naturalists it stands unique; and as an auxiliary to the purest, highest research, it is one of the signs of the times that wealth is not absorbed in material interests; that commerce counts it an honor to contribute to original investigation. May the number of such men increase, and such institutions multiply!



THE centre of gravity of the earth is the centre of the sphere formed by the surface of the oceans; or rather, owing to the flattening of the earth at the poles, it is a point equally distant, in opposite directions, from the level of the sea. The waters, being free to move, must of necessity conform themselves to this equidistance from the gravitating centre of the whole mass. Inasmuch, then, as any plane which cuts the earth into two parts through its centre of gravity must equally divide the weight of the whole earth, it follows also that the same plane would exactly bisect the great spheroid of the oceans. In each hemisphere the sea-level in all corresponding parts would be at the same distance from this centre; and whatever land and mountains there might be above the ocean in one half would have to be counter-balanced by land, or an excess of weight of some sort, in the other half. And this counterpoising weight must itself rise above the level of the sea, unless we say that one side of the world is composed of heavier materials than the other, of which there is not the least evidence or probability.

If the plane thus dividing the earth be that of its equator, there will be found in the northern hemisphere about 44,000,000 square miles