October 5, 1888.] 



SCIENCE 



167 



Sheridan, Byron, Fox, Pitt, Gustavus Adolphus, Wellington, and 

 George Canning. At twenty-six our future Lord Stratford helped 

 to found the Quarterly Rt-view, and introduced Gifford to Murray. 



Messrs. Fords, Howard, & Hulbert (New York) announce for 



publication ' The Democratic Party : its History and Influence ' 

 (new third edition, revised to date); and 'Tenants of an Old 

 Farm,' an illustrated work on insect-life, by Dr. Henry C. Mc- 



Cook, hitherto sold at ,$2.50, sold this season at $1.50. William 



R. Jenkins (New York) announces ' Paul Bercy's Works,' for the 

 study of French by the natural method ; ' La Langue Frangaise ; ' 

 ' La Langue Fran^aise ' (seconde partie) ; ' Livre des Enfants,' 

 pour r elude du Fra?!(ais, a primer full of illustrations, which serve 

 as object-lessons for the youngest children ; ' Le Second Livre des 

 Enfants ' (just published), intended for children also. It is full 

 of illustrations, and, like the first book, these form the basis upon 

 which the text is arranged, rendering it attractive in every way to 



children who have mastered the first book. The Burrows 



Brothers Company (Cleveland, O.) announces ' Christian Science, its 

 Truths and Errors,' by the Rev. H. Melville Tenney ; and ' The 

 Pocket Gem Pronouncing Dictionary,' by Lilla M. Tenney, on a 



new plan. The Century Company announces ' Ranch Life and 



the Hunting-Trail,' by Theodore Roosevelt. ' Principles of the 



Economic Philosophy of Society, Government and Industry,' by Van 

 Buren Denslow, LL.D., has just been published by Cassell & Co. 

 This firm continues its ' National Library,' edited by Prof. Henry 

 Morley, LL.D., a series of weekly volumes of reprints of standard 

 works. 



NOTES AND NEWS. 



The New York Academy of Science held its opening meeting 

 Oct. I. By the election of Professor Fairchikl to the chair of natu- 

 ral history at" the University of Rochester, the academy has lost one 

 of its most active members, — a loss which will be felt for a long 

 time to come. The publications of the academy have been pushed 

 forward most energetically, and the active editor. Professor Martin, 

 has succeeded in bringing them up to date, their value being thus 

 greatly enhanced. Mr. George F. Kunz sent in an interesting paper 

 on recent mineralogical discoveries, and several members reported 

 on the results of journeys undertaken during last summer's vaca- 

 tion. Dr. H. Carrington Bolton made some interesting remarks on 

 German and Austrian libraries which he had visited m pursuance 

 of bibliographical studies, and dwelt on the defects of the systems 

 of several of these libraries. On the other hand, he described the 

 management of the library of Strassburg as worthy of the highest 

 commendation. The arrangement is thoroughly systematical. 

 Visitors are allowed the greatest possible facilities, and any citizen 

 of Alsace Lorraine applying for books is entitled to have them sent 

 to his house, whether he lives in Strassburg or in some other part 

 of the province. Dr. Brinton gave a brief description of his studies 

 in English collections and libraries, and noted a large collection 

 from Bolivia which is said to contain an unexpectedly large number 

 of species and genera unknown to science. After a brief discussion 

 of the trap rocks of Pennsylvania and New York, Dr. F. Boas gave 

 a sketch of the ethnological results of his journey to British Colum- 

 bia, during which he visited most of the peoples of that province. 



— The committee on publications and lectures, of the Massachu- 

 setts Society for promoting Good Citizenship, have issued a circu- 

 lar requesting the clergymen of Massachusetts to prepare and 

 preach, and as far as possible publish, between now and the gen- 

 eral election in November, at least one sermon on the duties and 

 responsibilities of American citizenship. 



— A study undertaken by W. von Bezold a number of years ago 

 made it probable that thunder-storms have a period corresponding 

 to that of the rotation of the sun. In his inquiry he had used the 

 material collected at the meteorological stations of Bavaria. As, 

 however, an influence of this kind seemed very improbable, he did 

 not publish the results of his researches. Recently Hertz, Wiede- 

 mann, Arrhenius, and others have shown that by the influence of 

 radiation the conductivity of the air is changed, and thus a period 

 of the frequency of thunder-storms corresponding to that of the 

 rotation of the sun does not appear improbable. For this reason 

 Von Bezold has taken up his earlier researches, and carefully 



scrutinized the observations of thunder-storms in Bavaria and 

 Wurtemberg from 1880 to 1887. The Nalurwissenschaflliche 

 Rundschau reports on a paper on this subject read by Von 

 Bezold before the Berlin Academy of Science. He finds that a 

 period exists ; and the proofs he gives are so convincing, that he 

 feels encouraged to pursue this subject more fully. 



LETTERS TO THE EDITOR. 

 Floods in the Lowrer Mississippi. 



Major Powell, in his letter to the New Orleans Chamber of 

 Commerce, suggests as a means of regulating the lower Mississippi 

 the erection of large basins at the head waters of its tributaries in 

 the Rocky Mountains. " The cutting-power of a stream," he says, 

 " increases rapidly with an increase of sedimentary load." 



If this be correct, then there must be an increase in either quan- 

 tity or in velocity by the increasing sedimentary load, those two 

 constituting the working energy of the water, which is : quantity 

 times half the square of the velocity. As to the quantity, there is, 

 in fact, an increase. Draw a cubic foot of water from the river 

 and let it rest. The sediment will settle to the bottom, and is 

 therefore heavier than the amount of water it displaces, as other- 

 wise it would remain in suspension. For this reason a cubic foot 

 of water mixed with sediment is heavier than a cubic foot of clear 

 water. 



But how is it that this same sediment was in suspension in the 

 same water when it was in the river ? Because the water there had 

 velocity. Velocity has an equivalent in 'head' or water weight 



•xCmX-I^^ 



and just as much of this head will be used to carry along the sur- 

 plus weight of the sediment as is equivalent to this surplus. Dimin- 

 ished head is diminished velocity. Clear water, therefore, will flow 

 quicker (that is, have more working energy) than water mixed with 

 sediment, which will readily be seen when we imagine such an 

 amount of sediment to be added to the water that it would attain 

 the consistency of sirup. 



If, now, as Major Powell claims, the product of the two is in- 

 creased by the increase of sediment, then the gain in weight of the 

 quantity ought to be greater than the loss in velocity. This is not 

 likely, for the reason that the velocity in that product is squared, 

 and every loss in it, therefore, is squared too. It is furthermore not 

 likely, because every gain in weight creates an additional loss in 

 head, part of the latter being used to crush and pulverize the in- 

 crease of sediment from heavy bowlders in the mountains into fine 

 sand at the mouth of the river. There is only one grand total of 

 power corresponding to a certain head, and every deduction from 

 it is a loss which cannot be made up for again. 



The indisputable fact that rivers choked by sediment do more 

 lateral cutting than cleaned rivers, therefore, does not seem to be 

 exactly expressed by attributing this fact to an increase in cutting- 

 power of the water through sediment. If it is. Major Powell should 

 prove it. 



Again the letter reads, " The waters of the Missouri come 

 loaded with materials which go on cutting and grinding with con- 

 stantly increasing energy- in their journey to the sea, choking the 

 channel and cutting away the land." I should like to see this sen- 

 tence more fully explained, as I fail to understand its full meaning. 



As a matter of fact, there are other causes besides the action of 

 sediment which increase the amount of river-sediment by bank- 



