Price.] '^»''-' [March 3, IT, & 



feet thick ; when the ghiciers of Great Britain ploughed into the sea, and 

 when those of the Swiss Mountains had ten times tlieir present altitude ; 

 when every lake in Northern Italy was tilled with ice, and these frozen 

 masses extended even into Northern Africa ; when a sheet of ice, reachintr 

 nearly to the summit of Mount Washington * * (that is, having a thick- 

 ness of nearly six thousand feet, ; moved over the continent of North 

 America ; is it so improbable that, in this epoch of universal cold, the Val- 

 ley of the Amazons also had its glacier pour«d down into it from the ac- 

 cumulations of snow in the Cordilleras, and swollen laterally by the tribu- 

 tary glaciers descending from the table lands of Guiana and Brazil? The 

 movement of the immense glacier must have been eastward, determined as 

 well by the vast reservoire of snows in the Andes as by the direction of the 

 valley itself It must have ploughed the valley bottom over and over 

 again, grinding all the materials beneath it to a fine powder, or reducing 

 them to small pebbles ; and it must have accumulated at its lower end a 

 moraine of proportions as gigantic as its own ; thus building a colossal sea 

 wall across the valley." p. 425. But he found no striated stone as there 

 was no natural rock-surface in the valley; and admits "I have not here the 

 positive evidence which has guided me in my previous glacial investiga- 

 tions." p. 426. 



All this account of the Amazonian Valley is inconsistent with what Mr. 

 Agassiz had, in the same Journal, 403, said of a Northern and Southern 

 Ice-cap "moving to the Equator," and with all the other glacialists who 

 claim that it did not descend below the thirty-ninth degree of latitude. 

 This gigantic glacier certainly did not come from the South Pole ; hay, 

 wiien in the stage of thawing, it did not move at all. It was dammed in 

 by its own moraine or huge wall of debris ; and when it melted it became 

 a vast fresh-water lake. And Agassiz says: "In this shallow sheet of 

 water under the ice, and protected by it from any violent disturbance, those 

 finer triturated materials always found at a glacier bottom, and ground 

 sometimes to powder by its action, would be deposited and gradually trans- 

 formed from an unstratified paste containing the finest sand and mud, to- 

 gether with coarse pebbles and gras'el, into a regularly stratitied formation." 

 lb. 428. This is said to explain why this is not like the same glacial pro- 

 duct in Europe ; why it is stratified as a deposit of still waters, but does 

 not explain how the same material has a different appearance over the 

 general surface of Brazil ; how the trituration and stratification would go 

 on without motion of both ice and water, nor what, during such quiet 

 lake-like operation under ice, had become of the floods that were ever de- 

 scending from the greatest water shed of the world which must reach the 

 sea. The attempted theory demands too much, involves difficulties not 

 cleared up, and stands upon anotlier basis than that of polar glaeiation. 

 That the floods of the Amazon and all its tributaries sliould be self-dammed 

 into a lake of fresh water, and, at near the sea level, covered with ice un- 

 der the equator is a proposition that seems of the most extraordinary na- 

 ture, and self-condemning. 



