Petrographical Abstracts and Reviews 



Edited by ALBERT JOHANNSEN 1 



Benedicks, Carl, and Tenow, Olof. "A Simple Method for 

 Photographing Large Preparations in Polarized Light," Bull. 

 Geol. Inst. Univ. Upsala, IX (1910), 21-23. 



For the description of the comparatively simple apparatus used, 

 reference must be made to the original paper. 



W. T. SCHALLER 



Bowles, Oliver. Tables for the Determination of Common Rocks. 

 New York: Van Nostrand, 1910. i6mo, pp. 64+84 advs. 

 50 cents net. 



Cut bono ? 



Written, as this book is, for "beginners in lithology," it is especially 

 unfortunate that the author's statements are often very misleading. 

 For example, in the chapter on "Rock Classification" the statement is 

 made that "igneous rocks .... represent the original solid crust of 

 the earth," and that "sediments .... are but modifications, or recon- 

 structed phases, of this primary type." A short chapter on the deter- 

 mination of the rock-forming minerals is followed by 18 pages of tables 

 for the determination of the common rocks. The methods of identifica- 

 tion are given in extremely brief form, but would a "beginner," or any- 

 one else, classify andesite, quartz porphyry, felsite, or phonolite as "ashy, 

 and often with a few phenocrysts, mostly cellular" ? 



The book ends with a ten-page chapter on "Building Stones" and a 

 seven-page glossary. The volume is No. 125 of Van Nostrand's Science 

 Series and is uniform in size and binding with the remainder of the set. 



Albert Johannsen 



Bowman, H. L., and Clarke, H. E. "On the Structure and 

 Composition of the Chandakapur Meteoric Stone," Min. Mag., 

 XV (1910), 350-76. Pis. 2, and analyses. 



A full description, with extensive chemical work, on a large piece of 

 the meteoric stone which fell at or near Chandakapur, India, on June 6, 



1 Authors' abstracts will be welcomed and may be sent to Albert Johannsen, 

 Walker Geological Museum, The University of Chicago, Chicago, 111. 



