xiv CONTENTS. 



presented, 371—374. The past and present Glacial Couditions of the Ural, of the 

 Scaudiiiavian Ran<;e, and of We.'^t Greenland compared and commented on, 371- 

 374. — Past Glaciation of Northeastern North America, 375—387. Complica- 

 tion of the Phenomena, 375. Statement of the Facts, 37C-378. Character of the 

 Northern Drift, 376. Topographical Features of the two sides of the Continent 

 compared, 376. Depressed area in central portion of Drift Region, 376, 377. 

 Nature and distribution of the Drift Material, 377, 378 ; area over which this is 

 chiefly developed, 378 ; direction in which it has been carried, 378. Indications 

 of former greater Rainfoll, and of Currents of Water, 379. Opinions earliest held 

 by heads of great American Surveys in regard to the Origin of tlio Drift, 379, 380. 

 Difficulty of malving out the po.sitions of the Ancient Rivers, 380. The former 

 presence of Ice rendered necessary by the existence of Striated Rock Surfaces, 380, 



381. Character of this Striation, 381, 382. The Inland Ice of Greenland cannot be 

 accepted as explaining the Drift Phenomena of Northeastern America, 382. The 

 theory tliat the Ice of Greenland once extended over North America examined, 



382. — Examiuatiou of the question of the former existence of a General or 

 Continental Glacier, 382-385. Professor Dana's Views, 382, 383. Facts about 

 Ktaadn, 383, 384. Profes.sor Hamlin's Observations (in note), 383, 384. Ex- 

 amination of the evidence that a Continental Glacier once passed over the White 

 and Adirondack Mountains, 384. Boulders and gravel not proof of former 

 presence of Ice, 384. Complication of the Striation in New England, 384, 385. 

 G. A. Wheelock quoted, in regard to the Striation on and about Monadnock, 385. 

 Theories of the movement of the Continental Glacier in various directions at the 

 same time, 385. Ideas of J. F. Carll and Professor Dana, 385. The Continental 

 Ice sheet extended fiir beyond tlie limits which ought, by any possibility, to be 

 claimed for it, 385. Geological importance of tlie Ground Moraine much exag- 

 gerated, 386. The presence of Ice often invoked where Water really did the 

 work, 386. The foots in regard to Past Glaciation in Northeastern America not 

 yet sufficiently studied out to justify extensive tlieorizing, 386. 



SECTION V. 



Pii^suMi^ AND Gexer.vl DISCUSSION 387-394 



The theory of a Polar ice-cap must be abandoned, 387. The Glacial epoch a 

 Local Phenomenon, 387. An increase of cold would not bring about Extensive 

 Glaciation, 388. Views of Lecoq, 388, 389. The theory advocated by Frankland, 



389. The phenomena of the Glacial epoch a magnified form of Present Conditions, 

 389. — Comparison of the facts observed in various regions, 389-391; the 

 Caucasus, 389 ; the Sierra Nevada, 390 ; the Alps, 390 ; the Scandinavian Range, 



390, 391; Northeastern America, 391. — Theories of a Recurrence of 'Warm 

 and Cold Periods on the t-wo hemispheres discussed, 392-394. The views of 

 Adhemar and CroU, 392. Evidence in support of these views, 393. The author's 

 opinion of the value of this evidence, 393, 394. General conclusions, 394. 



