Geology and Mineralogy. 551 



Montreal. — Of this important work under the charge of J. B. 

 Porter and R. J. Dudley, to be completed in six volumes, vol- 

 umes III and IV were added in 1912. 



Report on the Building and Ornamental Stones of Canada. 

 Vol. I ; by Wm. A. Parks. Pp. xiii, 376 ; 77 plates. 



Pyrites in Canada ; Its occurrence, exploitation, dressing, and. 

 uses ; by Alfred W. G. Wilson. Pp. xi, 202 ; 27 plates, 29 

 figures. 



Bulletin No. 8. Investigations of the Peat Bogs and Peat 

 Industry of Canada, 1910-11 ; by A. Anrep. Pp. viii, 61 ; 19 

 plates, 1 figure, and 12 maps (in pocket). 



- 7. Die Erklarende Beschreibung der Landformen; by 

 William Morris Davis, edited by Dr. A. Ruhl. Pp. xvii, 565; 

 212 ills., 13 tables. Leipzig and Berlin, 1912 (B. G. Teubner). — 

 The scope of the present work is indicated hy the following 

 chapter headings : The Content of Geography, The Erosion 

 Cycle, Confrontation of Theory with Fact, Development of a 

 Deductive Scheme, Simple Structures, Complicated Structures, 

 Mountains, Volcanic Features, The Arid Cycle, The Glacial 

 Cycle, The Marine Cycle. The matter used was originally pre- 

 sented in a course of lectures delivered in Berlin during the 

 winter term of 1908-09. Much new material has been added 

 particularly in the chapters on deserts, glaciation and shore lines. 

 While the methods of research developed by the author as well 

 as the conclusions drawn are familiar to American geologists. 

 the present book will repay careful reading. It is the best gen- 

 eral treatment of Physiography which has so far appeared, and its 

 wealth of pictorial and verbal illustrations adds to its value as a 

 reference text. h. e. g. 



8. Ocean-depth Charts of the Berlin Institut fur Meeres- 

 Jcunde. — Three charts of ocean depths, prepared by Dr. Max 

 Groll and issued by the Institut fur Meereskunde of the Uni- 

 versity of Berlin, serve admirably to summarize present knowl- 

 edge of ocean basins. The charts are on a central scale of 

 1 : 40,000,000, and are specially projected according to Lambert's 

 true-area device, so as to include the Atlantic, the Pacific and the 

 Indian oceans with their southward extensions. The lands are 

 uniformly tinted in ochre ; the shallow continental waters, down 

 to 200 meters, in a lighter shade of the same color ; then increas- 

 ing depths for every 1000 meters are shown in darkening shades 

 of blue down to 6000 meters ; after which purple, pink and red 

 show more extreme depths. Several results stand forth clearly ; 

 large unexplored areas have contours of simple pattern, evidently 

 because of lack of data rather than because of simplicity of 

 fact. Several lines of soundings from California to Fiji demand, 

 much greater irregularity of bottom contours than can now be 

 drawn for the neighboring unexplored spaces. The most strik- 

 ing fact is the occurrence of maximum depths, not in the middle 

 of the ocean basins farthest from the lands, but in narrow troughs, 

 closely associated with the borders of the continents or with 



Am. Jour. Sci.— Fourth Series, Yol. XXXV, No. 209.— May, 1913. 

 39 



