232 Scientific Intelligence. 



9. The Copernicus of Antiquity; by Sir Thomas L. Heath. 

 Pp. 59. London, 1920 (Society for Promoting Christian Knowl- 

 edge) . — This is one of the series of Pioneers of Progress, in which 

 the author traces the speculations by which the Greek philoso- 

 phers sought to explain the astronomical observations of the 

 time. The most remarkable of these was the heliocentric 

 hypothesis proposed by Aristarchus of Samos (310-230 B. C.) 

 who also made estimates of the sizes and distances of the sun and 

 moon. This theory of Aristarchus was known to Copernicus and 

 mentioned in his writings but it failed of acceptance largely on 

 the authority of Hipparchus who rejected it for the reason that 

 a system in which the earth and planets revolved in circles about 

 the sun as a center did not afford as exact a description of the 

 phenomena as the rival theory of epicycles. The book contains a 

 bibliography, and notes about all that is known of astronomical 

 theory before the time of Ptolemy. f. e. b. 



10. Mathematik in der Natur; by Hermann Emch. Pp. 85 

 and 132 figures. Ziirich, 1921 (Rascher & Cie). — ^A popular 

 account of mathematical relations in plants, animals, and crystals, 

 which arise from the ordered arrangement of their cells or molecu- 

 lar structure, or derive from the operation of physical forces. 

 Two chapters are devoted to geometrical forms among crystals 

 and organized matter. One is given to number groups such as 

 appear in the leaf arrangement of plants, or in the teeth and 

 scales of fish. The three remaining chapters are occupied with 

 various consequences of mechanical laws and a brief discussion of 

 atomic structure. A few of the statements appear to be of doubt- 

 ful validity. It is a book that will interest the curious reader 

 rather than the student of science. f. e. b. 



II. Geology. 



1. The Circulation of the Earth's Crust; by Lieut.-Col. E. A. 

 Tandy, R. E. (Survey of India) . The Geographical Journal, May 

 1921, vol. 57, No. 5, pp. 354-376. — Colonel Tandy uses the expres- 

 sion "Circulation of the earth's crust" as a substitute for the 

 words "isostatic adjustment." He is dealing with the process 

 by which disturbed sections of the earth 's crust resume their state 

 of isostatic equilibrium. His paper is well worth reading by any 

 one haAdng to do with structural and dynamic geology, for he 

 raises objections to many old and generally accepted theories and 

 he advances substitutes which he feels are more logical and in 

 better accord with the observed geodetic and geologic data. 

 There are few, however, who will, in my opinion, give approval 

 to many of Col. Tandy's views. There are the best of reasons for 

 believing that there is a " sub-crustal undertow from areas of 

 deposition to those of erosion but we cannot accept Col. Tandy's 

 view when he says : 



