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Page:Popular Science Monthly Volume 24.djvu/154

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the weight of the overlying column of rock, may be forced upward by the pressure of the walls on either side. In that case, the channel might rise as fast as the river cut it down, so long as nothing occurred at the surface materially to diminish the height of the walls.

Shad, which were first introduced there seven years ago, are now to be found all along the coast of California, and are rapidly making their way northward. The "run" in the Columbia River this year was described as wonderful, and the fish were a drug in the market. In California they have not yet come into popular use, owing partly to the fact that the closed season established by law is just when they are in the rivers. The order of their running in that State is different from that in the Atlantic States. They appear in San Francisco Bay in October, and leave it in May; while for other parts of the coast their run begins later as the latitude increases.

The Convocation of the University of Oxford has voted £10,000 for building a laboratory, working-rooms, and lecture-room for the Waynflete Professor of Physiology, Dr. Burdon-Sanderson. The grant was opposed by some of the members of the board, on the ground of their objections to vivisection, but was carried by a majority of three in a house of one hundred and ninety-three members.

A curious application is made of liquid carbonic acid at Krupp's foundry, in Essen, Prussia. The cannon made there are bound with rings, which are put on in nearly the same manner as the tires are put on wagon-wheels; that is, they are heated very hot, and driven on over the cold cannon, so that when they cool they hold it very tight. Sometimes it is desirable to get the rings off. This is done by freezing the cannon by means of the evaporation of liquid carbonic acid, when they contract and leave the rings loose. The French journal, "La Production," calls the operation "a formidably neat one, and of really Herculean elegance."

Dr. Chaillé, of New Orleans, has made a study of the influence of the inundations to which Louisiana is subject upon health. He finds that they do not cause inevitably or generally any notable increase of malaria or of other disease, and that they certainly do not usually either cause or promote epidemics. Their direct influence is, therefore, not usually to be dreaded. They may, however, in certain soils and conditions be charged with after-influences of a deleterious character, as when the soil is loaded with malaria, or deposits of filth have accumulated upon it. Such soils and deposits, festering in the sun after the floods have retired, may develop very serious evils.

M. Perrier describes an Asteria (Caulaster pedunculatus) that was dredged up in the Travailleur expedition, which appears to furnish a link between the ancient crinoids and the modern star-fishes. It is a star-fish, having on its back a peduncle quite similar to that of the crinoids, which is surrounded by a system of plates resembling those that composed the "calyx" of those animals. The peduncle probably served as a support for the young star-fish while it was temporarily fixed, and was probably destined to disappear by the progress of development; but this view needs to be confirmed by further examination.

M. Marchand, having repeated with water some of the experiments which Professor Tyndall has performed on the air, declares that there is no really clear water in existence. Filling a bottle with the liquid, he covered it with black paper, and pierced in the paper two holes at opposite points. Looking through the holes at the light, the dust-particles floating in the water were made plainly visible. They were transparent, only two millimetres in diameter, and elastic enough to pass through the closest filters.

Mr. Joseph Willcox remarked at a recent meeting of the Academy of Sciences of Philadelphia on the scarcity of springs and running streams in Canada. Where streams exist, they are almost exclusively the outlets of lakes. He ascribes the feature to the fact that the ancient glaciers swept away a large proportion of the soil of the country, leaving the underlying rocks usually near the surface, and in many cases visible above the ground. Thus the material is deficient which, in countries where springs and streams abound, soaks up the rain and melting snow, and afterward gives out a perennial flow of water.

"La Nature" records the death, at Catania, Sicily, in the thirty-third year of his age, of M. Tedeschi di Ercole, an investigator of earthquakes and volcanic and other physical phenomena, and a frequent contributor to it on subjects relating to them.

Mr. Jacob Ennis specifies as two great works to be done on our sidereal system to ascertain what way the great ring of the milky way revolves, and to discover in what direction to look for the center of the system and estimate its distance. The tasks are to be wrought out gradually by observing and measuring the proper motions of the stars, and composing a map by the aid of which the relations of those motions to each other and to the common center may be determined. The details of his method are explained in a pamphlet of twelve pages published bv Judd & Detweiler, Washington, D. C.