Revieics — /. C. Russell on Hi. St. Julias. 277 



admitted that it may be difficult to distinguish the effects of 

 grounding icebergs from those of land-ice. Charles Darwin's 

 theory of the transport of boulders, from lower to higher levels, 

 by floating ice, on a subsiding land, affords the only satisfactory 

 explanation, it is urged, of the occurrence of erratics in Eastern 

 Canada at a higher level than the rocks from which they were 

 derived. Dr. G. M. Dawson is quoted as stating that he finds 

 himself in agreement with Dr. Hector and Dr. Hayden in attributing 

 the glacial phenomena of the great western plain of Canada to the 

 action of floating ice, though the rounding, striation, and polishing 

 of the Laurentian plateau, in the region of the Lake of the Woods, 

 is to be attributed to the ice of glaciers. Such a glacier, covering 

 the Laurentian uplands, liberated icebergs, which, depositing boulders 

 and sediment, formed the highlands of the second plateau, including 

 the Touchwood Hills, Moose Mountain and Turtle Mountain. The 

 changed climatal conditions are regarded as mainly attributable 

 to changes in the level of land ; and it is believed that the present 

 climate of Canada is separated from that of the Glacial age b}'' one 

 somewhat warmer, which coincided with an elevated condition of 

 land. The date of the Glacial period was anterior to the excavation 

 of the Niagara gorge, which is estimated to have required from 

 12,000 to 15,000 years. 



The fifth chapter gives a summary of local details in the regions 

 of Canada in which glacial phenomena have been observed ; and 

 the sixth chapter is an account of the fossils found in the deposits, 

 illustrated with figures. There is a final summary of conclusions. 



The book is illustrated with useful sections and woodcut maps. 

 Its teaching is valuable from the breadth of country examined, the 

 variety of phenomena considered, and. the breadth of view which 

 seeks to explain each set of facts by causes which are in harmony 

 with the physical conditions evidenced in the several regions of 

 Canada ; and although the tone of the book has more that of an 

 advocate recapitulating the steps of his exposition, now extending 

 over a long period of time, than may be necessary in an impartial 

 history of the Ice-Age, the story is well told, interesting in every 

 page, and forms a valuable epitome of laborious work. 



IL— Second Expedition to Mount St. Elias, in 1891. By Israel 

 C. Russell, United States Geological Survey. Extract from the 

 Thirteenth Annual Report, 1891-92. Pp. 91, Maps and Plates 

 iii.-xxi. and 6 Figures. (Washington, 1894.) 

 ri'^HIS Report contains the observations of a small exploring 

 X expedition, under the charge of Mr. Russell, which re- 

 visited in 1891 the glaciated regions between Mount St. Elias 

 and the sea-coast west of Yakutat Bay, in Southern Alaska. One 

 of the objects of the expedition was to attempt to reach the summit 

 of this mountain, but the difficulties proved too great and no higher 

 elevation than 14,500 feet was reached. Many valuable and im- 

 portant observations relating to the structure of the glacier, its 

 drainage, the nature of the moraines, and other points were 



