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THJE POPULAR SCIENCE MONTHLY. 



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, 80 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 differ- 

 ent 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 op- 

 posed by some of the members of the board, 

 on the ground of their objections to vivisec- 

 tion, 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 car- 

 bonic acid, when they contract and leave the 

 rings loose. The French journal, " La Pro- 

 duction," calls the operation " a formidably 

 neat one, and of really Herculean elegance." 



Dr. Chaille, 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, there- 

 fore, not usually to be dreaded. They may, 

 however, in certain soils and conditions be 

 charged with after-influences of a deleteri- 

 ous character, as when the soil is loaded 

 with malaria, or deposits of filth have accu- 

 mulated 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 ( Caulas- 

 ter pedunculatus) that was dredged up in the 

 Travailleur expedition, which appears to 

 furnish a link between the ancient crinoids 

 and the modem 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 tempo- 

 rarily fixed, and was probably destined to 

 disappear by the progress of development ; 

 but this view needs to be confirmed by fur- 

 ther examination. 



M. Marchand, having repeated with wa- 

 ter some of the experiments which Profej^sor 

 Tyndall has performed on the air, declares 

 that there is no really clear water in exist- 

 ence. 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 trans- 

 parent, only two millimetres in diameter, 

 and elastic enough to pass through the 

 closest filters. 



Mr. Joseph Willcox remarked at a re- 

 cent 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 out- 

 lets of lakes. He ascribes the feature to 

 the fact that the ancient glaciers swept away 

 a large proportion of the soil of the coun- 

 try, leaving the underlying rocks usually 

 near the surface, and in many cases visible 

 above the ground. Thus the material is de- 

 ficient which, in countries where springs and 

 streams abound, soaks up the rain and melt- 

 ing snow, and afterward gives out a peren- 

 nial flow of water. 



"La Nature" records the death, at Ca- 

 tania, Sicily, in the thirty-third year of his 

 age, of M. Tedeschi di Ercole, an investi- 

 gator of earthquakes and volcanic and other 

 physical phenomena, and a frequent con- 

 tributor 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 sys- 

 tem and estimate its distance. The tasks 

 are to be wrought out gradually by observ- 

 ing 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 by Judd & Detweiler, Washington, 

 D.C. 



