128 Scientific Intelligence. 



Elliptic geometries." A list of technical terms precedes the 

 index. The serious reader will be well repaid, for the time spent 

 in studying the text, by his gain in power of intuition and imagi- 

 nation, h. s. IT. 



11. Experiments ; by Philip E. Edelman. Pp. 256, 135 fig- 

 ures. Minneapolis, 19J4 (Philip E. Edelman). — A correct idea 

 of the scope of this volume may be obtained from the following 

 quotations taken from the title page, namely: — "Book 1. Selected, 

 grouped and graded experiments which may be repeated in a 

 simple manner, including some of the most brilliant demonstra- 

 tions in science, physics, chemistry, electricity, wireless communi- 

 cation and mechanics." "Book 2. The principles of original 

 experimenting in science, invention, and the industries together 

 with chapters on industrial testing and commercial experiments." 

 Since the book contains a very heterogeneous mixture of all kinds 

 of "stunts" and experiments it is in a class by itself. The numer- 

 ous half-tones and striking cover attract attention at once. On 

 the other hand, the diagrammatic text-figures are, in general, too 

 small and poorly lettered. The word coherer is consistently spelled 

 " coheror." One is somewhat surprised to have the frontispiece 

 and chapter 33 given to the experimental mill of the Washburn- 

 Crosby Company of Minneapolis. The text is not adapted to 

 class-room work; nevertheless, it may stimulate independent exper- 

 imentation on the part of those who have not the opportunity of 

 attending systematic courses in technical schools and colleges. 



h. s. u. 



II. Geology and Mineralogy. 



1. The Transportation of Debris by running Water ; by 

 Grove Karl Gilbert. Based on experiments made with the 

 assistance of Edward Charles Murphy. Pp. 263, with 83 

 tables, 3 plates, 89 figures. Professional Paper 86, U. S. Geol. 

 Surv., Washington, D. C, 1914. 



In engineering and in geology many problems arise the accu- 

 rate solution of which requires a knowledge of the power of a 

 stream to sweep material along its bottom. From the geologic 

 point of view: how much is the capacity of a stream to transport 

 sediment increased by a given increase in slope, or in volume, or 

 in breadth, or in depth, or in fineness of sediment? To turn the 

 problem around, in an ancient alluvial deposit, what kind of a 

 stream transported and deposited the material ? What was its 

 length, slope, volume, and velocity ? From the engineering point 

 of view : in a modern stream how much material and of what 

 sizes can be poured into it without overloading it and thereby 

 destroying arable lands, or what changes in transporting power 

 will be induced by straightening and deepening the channel ? 



Up to the present the little experimental work which has been 

 done to develop a knowledge of these subjects has been accom- 



