446 N. H. DA ETON — CATALOG OF PHOTOGRAPHS 



1372, 1373. Model M. Two stages, full size of model for class use. 



1374-1376. Model J. Three stages, full size of model, illustrating development of 

 an overthrust fault in soft strata beneath a harder series, and also accom- 

 modation of constant volume to change of form by shearing in two sys- 

 tems and displacement of triangular prisms. 



1377. Model J 1. Two views of one stage, large scale, illustrating major folds 



longitudinally related to thrusts. 



Photographed for G. P. Merrill, United States National Museum 

 8 by 10 inches 



1378. Hypothetical map of the North American continent during the period of 



maximum glaciation, in early Pleistocene time. 



1379. Hypothetical map of the North American continent at the close of Neocene 



time. 



1380. Hypothetical map of the North American continent in Middle Cretaceous 



time. 



1381. Hypothetical map of the North American continent at the close of Carbonif- 



erous time. 



1382. Hypothetical map of the North American continent in early Carboniferous 



time. 



1383. Hypothetical map of the North American continent in early Devonian time. 



1384. Hypothetical map of the North American continent in earliest Silurian time. 



1385. Hypothetical map of the North American continent in early Lower Cambrian 



time. 



1386. Hypothetical map of the North American continent during late Algonkian 



time. 



Photographed by J. S. Diller 

 6J by 8| inches. Negatives in United States Geological Survey 



1387. Hon. 0. D. Walcott, Director United States Geological Survey ; Major J. W. 



Powell, Director United States Bureau of Ethnology ; Sir Archibald Geikie, 

 Director of Geological Survey of Great Britain (No. 359 G). 



1388. Geikie excursion party, Jefferson rock, Harpers ferry, West Virginia, May, 



1897 (No. 358 G). 



1389. Geikie excursion party, Jefferson rock, Harpers ferry, West Virginia, May, 



1897 (no negative). 



1390. Geikie excursion party, Jefferson rock, Harpers ferry, West Virginia, May, 



1897 (No. 360 G). 



Photographed by the late Dr G. H. Williams, of Johns Hopkins University, Baltimore, 



Maryland 



4 J by 62 inches 



Photographs of laboratory specimens 



1391. Anticlinal fold ; Animikee slate, Pigeon point, lake Superior. 



1392. Folded hala-flinta; Naerodal, Norway. 



