PHOTOGRAPHS DONATED BY U. S. NATIONAL MUSEUM. 387 



1370. The Washington boulder. A glacial-drift boulder at Conway, New Hamp- 



shire. This is a very solid block of Conway granite. It cannot be shown 

 to have been transported more than one mile. Its dimensions are 30 by 

 40 by 25 feet. View from the northeast. 



1371. Cathedral rock. Profile view from the northeast. North Conway, New 

 • Hampshire. The hills show the typical roche moutonnee outline. 



1372. Marine erosion of till, Boston harbor. 



1373. Marine erosion of till, Long Island head, Boston harbor. 



1374. Roche moutonnee, Marblehead, Massachusetts. 



1375. Ship rock, Massachusetts. A glacial-drift boulder at Peabody. This boulder 



is 51 feet long, 27 feet wide, and 31 feet high. View from the north. The 

 source is probably local. 



1376. Churchill rock, Nottingham, New Hampshire. A glacial-drift boulder on 



Pawtuckaway mountain. This boulder is 62 feet long, 40 feet wide, and 

 40 feet high ; estimated to contain 75,000 cubic feet and weighs 6,000 tons. 

 The source is probably local. View from the southwest. 



1377. Marine erosion of till, Boston harbor. Cliff on eastern edge of Great Brew- 



ster islands (a drumlin). 



1378. Glacial-drift boulders, Rattlesnake island, lake Winnepesaukee. New Hamp- 



shire. 



1379. Hypothetical map of the North American continent during the period of 



maximum glaciation, in early Pleistocene time. 



1380. Hypothetical map of the North American continent at the close of Neocene 



time. 



1381. Hypothetical map of the North American continent in Middle Cretaceous 



time. 



1382. Hypothetical map of the North American continent at the close of Carbo- 



niferous time. 



1383. Hypothetical map of the North American continent in early Carboniferous 



time. 



1384. Hypothetical map of the North American continent in early Devonian time. 



1385. Hypothetical map of the North American continent in earliest Silurian time. 



1386. Hypothetical map of the North American continent in early Lower Cambrian 



time. 



1387. Hypothetical map of the North American continent during late Algonkian 



time. 



Thirty-four views presented by J. F. Kemp 



The Minnesota views were taken during the summer of 1894; all others in the 



summer of 1896. Size, 4| by 6g inches 



1388. Open cut at iron mines of the Minnesota company. Tower mine, showing 



forking of beds, Vermillion Lake district. 



1389. Open cut at iron mines of the Minnesota company near Tower, Minnesota. 



1390. Sunken ground over the Chandler mine, Ely, Minnesota. 



1391. Sunken ground over the Chandler mine, Ely, Minnesota. 



1392. Auburn mine near Virginia, Minnesota, stripped ready for mining. 



