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THE POPULAR SCIENCE MONTHLY. 



gained the heat of the Gulf Stream ; thus for the eastern part we 

 have cold accounted for and for the western part heat but the 

 glacial condition extended the whole length ; therefore, while it 

 seems possible that glaciers might form on the western part by 



reason of the snowfall 



being great, the case 

 is different for the 

 eastern part, which 

 seems to have been en- 

 tirely deprived of its 

 vapor - making ele- 

 ment, heat, for even 

 under existing condi- 

 tions the mean tem- 

 perature of Greenland 

 and Labrador is low 

 and the snowfall light 

 as compared with 

 Alaska. The answer 

 is made to this that 

 western winds carried 

 the moisture-laden at- 

 mosphere from the 

 west coast to the east, 

 but these winds would 

 have to cross the Sier- 

 ra Nevada and Rocky 

 Mountains, forcing 

 them to higher altitudes, resulting in the condensation and pre- 

 cipitation of their vapor upon the mountains. This difficulty is 

 overcome by having recourse to the immense lava outflows, cov- 

 ering thousands of square miles west of the Rocky Mountains, 

 which are supposed to have taken place about the Glacial period ; 

 this molten mass is supposed to have generated so much heat as 

 to modify the customary effect of mountain ranges and get the 

 vapor-laden atmosphere to the needed point and thus satisfy the 

 hypothesis, but it offers no explanation of the Glacial period in 

 Europe. 



Many leading geologists favor this view, while others think 

 the truth will be found in a combination of the last two hypothe- 

 ses, both being in some measure contributory to the result. 



Fossil man has been found in certain countries associated with 

 the remains of certain animals, among which are the mammoth, 

 woolly rhinoceros, cave bear, fossil horse, Irish elk, cave hyena, 

 cave tiger, reindeer, elk, musk ox, aurochs, hippopotamus, lion, 

 and others. These animals are either now extinct or are, for cli- 



Spy Ho. 1 Spy No. 2 



FIG. 3. SUPERIMPOSED OUTLINE DRAWINGS OF SKULLS. 



