made as easy as possible. "All three agencies combined are making the surface drainage almost as perfect as if a series of impervious roofs covered the land, and all the flow from them were conducted by pipes into one common channel." Consequently, "springs once copious have disappeared; streams formerly perennial alternately overflow their banks and run dry. The natural regulators of the streams having been destroyed, whenever there is an excessive rain it is rapidly carried into the streams, which, gradually uniting their waters, often constitute floods in larger channels which no human appliances can control." Dikes and levees will check the evil for a time, only to make it greater in the future. The only possible remedy for all these evils is "to hasten as quickly as possible to undo our work and recreate the natural reservoirs we have destroyed. By reforesting the swamps and the higher land which surrounds them and the lakes, "we shall restore them to their proper place in the economy of Nature." The lakes should be restored to their former dimensions, and enlarged wherever practicable. A scheme kindred to this is that of creating artificial reservoirs at the sources of rivers, as at the sources of the Ohio in the Alleghany Mountains, by damming up the ravines of the smaller streams.
Earth-Contraction and Mountains.—Mr. William B. Taylor lately read a paper before the Philosophical Society of Washington before which he suggested that the crumpling of the earth's crust, with the formation of mountain-ranges, was a result of modification in the spheroidity of the globe produced by a change in the length of the day, which change is an effect of the retarding action of the tides. It is established, in the author's mind, as beyond a reasonable doubt, that our present day is considerably longer than the day of early geological times. Supposing the equatorial radius of the earth to have been once one tenth greater and the polar radius one tenth less than they are now, it is evident that, from the very slow but never-ceasing contraction of the equatorial shell, due to diminution of rotatory motion, "this crust would be subject to an unremitting stress of lateral compression as relentless as that from the old hypothetic shrinkage of volume by reduction of temperature. Is it not precisely this morphologic contraction whose effects and records are everywhere apparent in the crumpling of the earth's crust?" On this view the facts may be explained that the circumpolar regions, where the crust has, by the theory, been stretched, are relatively free from mountains or plications, while the intertropical region contains the highest elevations. So strongly impressed is Mr. Taylor "with the inevitable operation and potency of this unquestioned retardation of rotation that, were all traces of any differential action masked and obliterated, he would still hold to it as the one efficient cause to account for the prominent constriction of the crust displayed in every land. But the differential traces of oblateness have not been obliterated—masked though they may be, to some extent, by other perturbations." From various conditions, he adds, "we may infer that in all geological ages the progress of elevation has been in excess of that of degradation by erosion; that in all ages mountain-building has been at a maximum; that is, that the uplifted heights have been the greatest which the average thickness of the crust at the time was capable of supporting; so that the former has been a constant function of the latter, the ratio being probably not far from one fifth." The increasing maximum of elevation has probably now reached its limit, for both the processes of equatorial contraction and of internal temperature reduction are going on with extreme and lengthening slowness; "and the whole remaining subsidence of the intertropical oblateness can not exceed five miles, during the vast ages in which the earth's rotation shall be entirely arrested."
Snake-Poisoning.—Dr. G. C. Roy, contrasting the physiological action of snake poison and the symptoms of rabies, has made the suggestion that the venom of the cobra might be tried to counteract the morbid phenomena of rabies. An interesting compendium of facts respecting snake-poisons has been published in Calcutta by Mr. Vincent Richards, from which we learn, among other things, that we have no antidote to the poison when it has once fully entered into the system. If the venom can
