144 THE ICE AGE IN CANADA. :, 



attention has been directed. Eecent excavations in the 

 Montreal mountain have enabled Prof. Kennedy and Prof. 

 Adams to observe marine shells and gravel at a still higher 

 level than that of the old beach above Cote des Neiges, 

 which was so long ago described by Sir Wm. Logan and 

 Sir Charles Lyell. The new positions are 534 to about 

 600 feet above the sea. Let us place this fact along with 

 the discovery of the skeleton of a whale at an elevation of 

 420 feet, as far west as Smith's falls, in Ontario, and with 

 that recorded by Prof. Bell in the report of the Geological 

 Survey for 1870-71, of the occurrence of these same 

 shells on the high lands north of lake Superior, at a 

 height which, taking the average of his measurements, is 

 547 feet above the sea level. Let us further note the 

 fact, that in the hills behind Murray bay and at Les 

 Eboulements I have recorded the occurrence of these 

 remains at the height of at least 600 feet. We have, 

 then, before us the evidence of the submergence of a 

 portion of the North American continent, at least 1,000 

 miles in length and 400 miles in breadth, to a depth of 

 more than a hundred fathoms, and its re-elevation, with- 

 out any appreciable change in molluscan life. 



IV. — Date of the Glacial Period. 



The question of the time that has elapsed since the 

 glacial period is closely connected with that as to the 

 causes of the climatal changes involved. If these last 

 were astronomical, and dependent, as Croll* has ably 

 argued, on the varying eccentricity of the elliptical orbit 

 in which our earth moves, along with the gradual proces- 

 sion of the equinoxes on the equator, then the culmination 



* " Climate and Time in their Geological Relations." 



