BY E. C. ANDREWS 801 



"Ifc should be said by way of qualification that the low-tide 

 stream and the breeze-lifted wave have a definite though sub- 

 ordinate influence on the topographic configuration. After the 

 great flood has passed by, the shrunken stream works over the 

 finer debris . . . the smaller waves of fair weather construct 

 a miniature beach profile adapted to their size. . , . Thus, 

 as early perceived by De la Beche* and Beaumont,! it is only 

 for a short time immediately after the passage of the great storm 

 that the beach profile is a simple curve; it comes afterwards to 

 be interrupted by a series of superposed ridges produced by 

 storms of different magnitude." 



McGee's paper of 1 883(21, «) is a remarkable statement. Atten- 

 tion is drawn therein to typical glacial profiles, and a great case 

 for glaciation is here unmistakably stated. 



Russell in 1889, (25, a) Cushing(6,«) in 1891, and Russell again 

 in 1 892(25, Z^) experienced difficulties in accepting the glacial 

 explanation for certain cailon-contours. Especially were these 

 difficulties experienced in attempting explanations of the moraine- 

 overriding habits, and general stagnation of the Muir and other 

 glaciers. 



McGee in 1894,(21, &) \vhen considering the mechanics of glacia- 

 tion, Culver in 1895(5,a) and Reid in 1896(24,«) all record appa- 

 rently anomalous phenomena, which, however, apparently admit 

 readily of explanation on the assumption of former ice-floods. 



The ' Great Ice Age,' by Dr. J. Geikie,(16) furnishes a grand 

 summary of glacial knowledge up till 1898. Incorporated with 

 this volume is a concise statement by Chamberlin of glaciation 

 in North America. 



The articles by Chamberlin(3,a,6,c) and Salisbury (26) throw 

 much light on glacial mechanics. 



In the illustrations accompanying Chamberlin's Reports, one 

 sees repeated evidence of the shearing and overthrusting of ice- 



* Manual of Geology. Philadelphia, 1832, p. 72. 

 t Le9ons, p. 226 and pl.iv. 



