NOVKMIIKU y, ISSo.] 



SCIENCE. 



627 



foitj-eight illustrations, not one represents a 

 cliaracteristie slono iniplemeut of this coun- 

 tr3-. Tlie little that our author finds to say 

 under the comprehensive title of ' rrehisloric 

 man in America ' is included in twelve pages, 

 constituting chapter vii., and is mainly a review 

 of Sqnier and Davis's Ancient niominieuls of 

 the Mississippi valley, with brief reference to 

 certain discoveries recorded so long ago as 

 the publication of Gliddon and Nott's Types 

 of mankind. Mr. Joly might readily have 

 done far better. No mention is made of tiie 

 vast amount of material gathered within the 

 last decade, that bears so strongh- upon 

 the vexed question of man's antiquity on this 

 continent. The scores of publications of the 

 Smitlisonian institution, the invaluable reports 

 of the Peabody museum, and the transactions 

 of our learned societies generally, have been 

 quite overlooked ; and a vain attempt has 

 been made, in lieu thereof, to bolster up the 

 claim of antiquity of America's earliest people 

 b-y reference to the mounds of the Ohio valley, 

 many of whicii have recently lost tiieir claim 

 to a pre-Indian origin, and others, doubtless, 

 will yet be shown to have been erected by the 

 ancestors of our modern redskin. As a r&sumi 

 of European archeology, it is valuable, but 

 not otherwise. To the American students of 

 the science it will prove disappointing. 



Hi/flrau!ic lahlex for the calculation of Ike dhcharge 

 lliroiii/h sewcrK, pipes, nnil co'nlnils ; based on 

 KuKer's formula. Hy P. •). Flyxn. New V'ork, 

 D. Van Nuslrnnil, 1883. (Van Nostrand's science 

 series, no. 67.) 135 p. 24°. 

 KuTTEu's formula for determining the veloci- 

 ty of flow of water is one of the class which 

 has the general form v = c sjTs, where r is the 

 ratio of the cross-section a to the wetted pe- 



rimeter, and .s is the sine of the slope ; but the 

 cocllicicnt c is of such a complex form, tli.it 

 the application of the formula to definite prob- 

 lems in water-supply and sewerage is some- 

 what tedious. This collection of tables is 

 designed to facilitate the work, and gives 

 values of r, cy'r, and ac\/r, for circular and 

 egg-shaped sections, and of .s- and \J s for dif- 

 ferent slopes. The coefficient of roughness or 

 friction used is .015, and a number of exam- 

 ples make clear the use of the tables. Engi- 

 neers who have snch work in their practice will 

 find these tables convenient. 



Chemical problems, with brie/ statements of the princi- 

 ples involrctl. By J.\mks C. Foye. New Yoi'k, 

 Van Nostranil, 1883. (Van Nostrand science 

 series, no. 69.) 0-1-141 p. 24°. 

 The value of chemical problems as a prac- 

 tical illustration of the rules of stochiometry 

 is recognized l)y every teacher of chemistry. 

 A thorough knowledge of chemical arithmetic 

 is constantly required in the laboratory, and 

 it can only be gained by actual practice in 

 the solution of problems. Tiie convenience of 

 having a collection of examples at hand will 

 therefore be apiireciated bv teachers ; and this 

 book will doubtless supplj' a deftciency to 

 those wiio prefer the problems arranged inde- 

 pendently of the text-book. A great variety- 

 of examples are presented, with verj- full illus- 

 trations of the relations wiiich exist between 

 the factors and products of chemienl reactions, 

 beside calculations of atomic; and molecular 

 weights, specific and latent heat, specific grav- 

 ity and vapor density. Examples are also 

 introduced on the metric .system of weiglUs 

 and measures, thermometric scales, and the 

 laws of Mariotte and Charles. 



WEEKLY SUMMARY OF THE PROGRESS OF SCIENCE. 



ASTRONOMY. 

 Origin of the lines A and B in the spec- 

 trum. — M. Ksiiioff. by e.Npfriments at the physical 

 laliDrutory of the University of St. Petersburg, has 

 shown that the Hues of the solar spectrum known 

 as A and li are (hie to the oxyseii of our atmos- 

 phere, lie employed a tube twenty metres in 

 length, closed with glass plates, in which tube the 

 gas under investigation could be comlensed under 

 pressures of fifteen atmospheres or less, proper care 

 being taken to dry it thoroughly. The telluric char- 

 .acter of these lines has been generally admitted, but 

 has of late been called in question by Mr. Abney, who 



suggested that they might be due to cosmical hydro- 

 carbon gas of some kind, diffused through space in 

 accordance with Siemcns's theory. M. Egoroff sets 

 this question at rest, having determined by direct 

 experiment that none of several different hydrocar- 

 bons tried gives any such bands, while oxygen un- 

 mistakably does give them. — {Camples rendu."!, Aug. 

 27.) c. A. Y. [327 



On the assumption of a solar electric poten- 

 tial. — AVeruer Siemens discusses the hypothesis 

 proposed by his brother (Sir W. Siemens), that the 

 sun has a high electric potential, due to the friction 

 of the dissociated matter which, according to his 



