Page:Popular Science Monthly Volume 56.djvu/751

Rh to the top, and would carry off the salts. This being at present impracticable on the large scale that would be required, such expedients as surface flooding and such cultivation of crops as would tend to check evaporation are suggested. The pernicious effects of "black alkali" or sodium carbonate are seen when it forms as much as about one tenth of one per cent of the soil, in the corrosion and solution of vegetable matter—the stems of plants—exposed to it. It also dissolves the humus or vegetable mold, forming dark-colored solutions and depositing a black residue upon the evaporation of the water—whence its name—and it destroys the tillability of many soils. The "white alkali" or sodium sulphate can be borne in much larger proportions in the soil, and promotes the best crops just before it completely destroys them. The author remarks that the foundations of a number of buildings in Billings, Montana, are gradually becoming insecure because of the disintegration of the rock, due to the absorption of alkali salts, followed by the evaporation of the water and the deposit of salts within the pores of the rock. As the process continues, the rock particles are forced apart.

Future of the New York Canals.—The Committee on Canals of New York State recommend decidedly in their report to the Governor that those highways should not be abandoned but maintained, and the principal ones enlarged, while the others should be kept up as navigable feeders. Of two projects for enlarging the Erie Canal, that undertaken in 1895, with modifications to be executed at a cost of $21,161,645, and a larger one to cost $58,894,68, the committee prefer the larger one, because it will permanently secure the commercial supremacy of New York, while the other is "at best only a temporary makeshift." An important principle emphasized in the report is that the efficiency of the canals depends upon their management as well as upon their physical size. Therefore a policy should be followed that will encourage transportation companies to seek the use of them; mechanical means of traction should be employed, and mechanical power should be substituted for hand power in certain operations; the force engaged upon them should be organized on a more permanent basis of fitness, so as to furnish an attractive career to graduates of scientific institutions; and efficient guards should be thrown over the expenditure of money "so as to make impossible a repetition of the unfortunate results of the $9,000,000 appropriation."

Floating Stones.—While engaged in scientific research in southwest Patagonia, Mr. Erland Nordenskiold observed a considerable number of small fragments of slate floating upon the surface, packed together in larger or smaller clusters. The surface of the stones was dry, and they sank immediately when it became wet. Their specific gravity was 2.71, that of the water being 1.0049. The fragments contained no air cavities perceptible to the naked eye, but small, gaseous bubbles could be seen attached to their under surfaces, and stones on the very fringe of the beach which were just beginning to float were observed to be lightened by gaseous bubbles. The author was not able to investigate the phenomenon more closely, but believes that besides the visible bubbles they were surrounded by an envelope of gas, supported by an insignificant coating of algæ, by which they are enveloped. The greasy surface of the mineral also prevented the water from adhering to them, and caused them to be surrounded with a concave meniscus, which contributed much to their floating.

The "Periodicity of War."—The doctrine of "the periodicity of war" was presented at the Lake Mohonk Conference on International Arbitration in May–June, 1899, by General Alfred C. Barnes, with the introductory remark that "no one deprecates war more than the soldier who serves from a sense of duty." The speaker said that "with all our privileges, and in spite of the elevated spirit that undeniably prevails among us, the original savage lurks in the hearts of men here as elsewhere." In two hundred and twenty-five years we have had ten principal wars—five during the colonial period and five since our independence was undertaken. The average interval between wars has been about twenty years—"an extremely