REVIEWS 481 



Lehrbuch der geologischen Formationskunde. By Dr, Emmanuel 

 Kayser. Dritte Auflage, 1908. Stuttgart: Verlag von Ferdi- 

 nand Enke. 

 The third edition of this very useful textbook contains many changes of 

 a minor character which were rendered necessary by the recent rapid strides 

 in statigraphical research. A few sections have been extensively revised 

 and rewritten. The volume is one-sixth larger than the second edition, 

 and contains over 100 additional illustrations of fossils, besides new figures 

 and plates. H. H. 



Physical Geography of the Evanston-Waukegan Region. By W. W. 

 Atwood and J. W. GoLDTHWAiT. Urbana, 111. : Illinois State 

 Geological Survey, Bulletin No. 7, 1908. 



This forms the first of a series of " Educational Bulletins " descriptive 

 of various parts of Illinois, and should be of particular interest to teachers 

 of physiography and geology. Excellent accounts of the work and deposits 

 of continental glaciers and of the evolution of lake shore-lines are given 

 as well as summaries of the history of the greater Great Lakes and of the 

 features characteristic of the various stages of an erosion cycle. 



H. H. 



The Evolution of the Falls of Niagara. By J. W. Spencer. 470 pp., 

 43 pis., 30 figs. Ottawa: Canadian Geological Survey, 1907. 

 From 1842 to 1905 the average recession of the Canadian Falls was 

 found to be 4.2 ft. per year, and of the American Falls only 0.6 foot per 

 year. G. K. Gilbert (U. S. G. S.,.Bull. 306) calculated the retreat for the 

 two falls at 5 ft. and 3 in. respectively. The former breadth of the Cana- 

 dian Falls has been reduced nearly one-seventh by commercial operations, 

 and if the whole amount of water granted by the present franchises for 

 power purposes be utilized these falls will shrink from 3,000 ft. to 1,600 ft., 

 while on the American side there will remain but a few disconnected streams. 

 New soundings show a depth of 92 ft. below the level of Lake Ontario at 

 the head of the Whirlpool Rapids and furnish equally interesting figures 

 for other parts of the river. Much new light is thrown on the history of 

 the Whirlpool — St. David buried channel, and the truth about this feature 

 seems finally to have been made clear. The ancient stream which flowed 

 in it never drained the Erie basin, nor does it account for much of the gorge 

 above the Whirlpool, as has been sometimes stated. To its great depth, 

 however, it caused the formation of the Whirlpool. A small, superficial. 



