WARREN UPHAM, ESQ., ON CAUSES OF THB iCE AQE. 213 



the place of the pole since the Glacial period, and froMi 

 even earlier geologic times, has been without greater 

 changes of position than would lie inside the area of a block 

 or square enclosed by the intersecting streets of a city.* 

 2S We come now to the wholly terrestrial or geologic theory 

 of the causes of the Ice age, which, in terms varying with 

 increasing knowledge, has been successively advocated by 

 Lyell, Dana, Le (^onte, AVriglit, and others, including the 

 present writer. This theory is called Ijy Professor James 

 Geikie the *' earth-movement hypothesis," and is adversely 

 criticized by him in a paper which forms, with its accom- 

 panying discussion, pages 221-26f in vol. xxvi (1893) of the 

 Journal of the Transactions of the Victoria Institute. Accord- 

 ing to this explanation, the accumulation of the ice-sheets 

 Avas due to uplifts of the land as extensive high plateaus 

 receiving snowfall throiighout the year. 



M Geology is indebted to Gilbert in his U.S. Geological 

 {Survey monograph, Lake Bonneville, for the terms epelrot/en/f 

 and epeirogenic (continent-producing), to designate the broad 

 movements of uplift and subsidence whicli affect the whole 

 or large portions of continental areas or of the oceanic basins. 

 This view, accounting for glaciation by high altitude, may 

 therefore be very properly named the epeirogenic theory. 

 25 In the first edition of the Frinciples of Geology (1830), 

 Lyell pointed out the intimate dependence of climate upon 

 the distribution of areas of land and water and upon the 

 altitude of the laud. In 1855 Dana, reasoning from the 

 prevalence of fjords in all glaciated regions and shov/ing 

 tliat these are valleys eroded by streams during a formerly 

 greater elevation of the land previous to glaciation, a.nd 

 Irom the marine beds of the St. Lawrence valley and basin 

 of Lake Champlain belonging to the time immediately 

 following the glaciation, announced that the formation of 

 the drift in North America was attended by three great con- 

 tinental movements: the first upward, during which the 

 ice-sheet was accumulated on the land ; the second down- 

 ward, when the ice-sheet was melted away ; and the third, 

 Avithin recent time, a re-elevation, bringing the land to its 

 present height.* But with the moderate depth of the 

 Ijords and submarine valleys then known, the amount ol 



* Fortnighthj Review, new series, vol. liv, pp. 171-183. Aug., 1893. 

 + Froc. Am. Asfoc. for Adv. of Science, vol. ix, for 1855, pp. 28, 29 ; Am. 

 Jour, of Science, II, vol. xxii, pp. 3?8, 329, Nov. 1856. 



