96 The Amenca?i Geologist. August, i899 
/. A Decrease in the Original Heat of the Globe. 
The first of these theories is universally admitted, and 
taught in even elementary works on physical geography, but it 
fails to account for all the phenomena accompanying the Ice 
age, or to account for the disappearance of that age, and, so 
far as the author is aware, has not been presented in such form 
as to satisfactorily account for "geological" and present 
climates in rigid conformity with the facts and known laws. 
Nor has it been presented in such form as to account for the 
occurrence of glacial phenomena during each of the great eras 
of geological time; nor again does this theory present any 
mode of accounting for the rise in temperature since the cul- 
mination of the Ice age. 
The idea that the earth was, at an early period of its history, 
a heated mass is recognized and admitted by nearly all physi- 
cists. Some of the earlier geologists have attempted to ac- 
count for the climatic changes which are recorded by fossil life 
upon the basis that the gradual cooling of the globe was the 
cause of these changes in temperature. 
But the complications introduced by the announcement 
that the earth has passed through an Ice age, and the interpre- 
tation of ice action in earlier ages into proofs of "glacial pe- 
riods", have caused most geologists to abandon this view. How 
thorough this abandonment has beeen can be seen from the 
following quotations: 
"It is evident that the idea of connecting the phenomena 
"of the internal heat of the globe with terrestrial climates, 
"whether of the present or of the past geological ages, must 
"be entirely abandoned, as it has been by most writers on this 
"subject. The hypothesis cannot be allowed to stand as even 
"one of the possible theories of climatic change."* 
"In fact is seems almost certain that during the whole re- 
"corded history of the earth, i. e., during the time that it has 
"been inhabited by organisms, the surface temperature of the 
"earth has been almost wholly due to external causes."! 
"The first theory brought forward to account for glacia- 
"tion, was that the earth having been originally in a fiery state. 
*Whitney — The Climatic Changes of Later Geological Times. 
fLe Conte — Elements of Geology; p. 381. Third Edition, N. Y., 
i8qi. 
