Geological Papers. 73 



terrestrial contraction and gravitation." (Popular Science 

 Monthly, October, 1879, p. 833.) 



On the same subject Geikie says : 



"It has been demonstrated that the protuberance of the 

 earth at the equator so vastly exceeds that of any possible 

 elevation of mountain masses between the equator and the 

 poles that any slight changes which may have resulted from 

 such geological causes could have only an infinitesimal effect 

 upon the general climate of the globe." (The Great Ice Age, 

 p. 98.) 



We must, therefore, fall back to Croll's theory, which Mr. 

 Wallace and many other scientists and geologists say was not 

 sufficient to produce so protracted a glacial epoch as is sup- 

 posed to have existed. But if Mr. Croll's theory, or even Mr. 

 Wallace's, is accepted it is simply because no better one has 

 been advanced, for it does not account for a contemporaneous 

 southern ice sheet which, as is proved below, did then exist. 



As evidence of contemporaneous glacial action, Le Conte 

 says that the glacial action in the glacial epoch was as exten- 

 sive in the southern hemisphere as in the northern. (Elements 

 of Geology, p. 596.) 



In reference to the same, Dana says : 



"In South America in glacial times, indications of great ice 

 masses are met with from Fugia as far toward the equator as 

 37 , and especially, as Agassiz has shown, in the great valley 

 between the Andes and the coast mountains to the latitude of 

 Conception." 



He also states on the same page that there were glaciers in 

 that epoch in New Zealand, and also in Australia and Tas- 

 mania. (Manual of Geology, 4th ed., p. 977.) 



Now, since the above-mentioned men are recognized au- 

 thority on this subject, it is evident, beyond the least shadow 

 of a doubt, that the glacial epoch was not caused by the com- 

 bined influence of northern elevation, the precession of equi- 

 noxes, and maximum eccentricity of the earth's orbit, for as 

 Mr. T. J. Bonney says (Story of Our Earth, p. 502), the pre- 

 cession of the equinoxes and aphelion winter in conjunction 

 would produce a cold climate in one hemisphere and the direct 

 opposite in the other, because if said aphelion winter and the 

 precession of equinoxes in conjunction would make the winters 

 twenty-two days longer than now in the northern hemisphere, 



