THE LIFELESS EARTH 27 



down by these sediments. It appears that the internal heat 

 engine is far more active in the slowly cooling continental areas 

 than in the rapidly cooling areas underlying the oceans, as 

 manifested in the continuous outflows of igneous rocks, which, 

 especially in the early history of the earth — at or before the 

 time when life appeared — covered the greater part of the earth's 

 surface. The ocean beds, being less subject to the work of the 

 internal heat engine, have always been relatively plane; except 

 near the shores, no erosion has taken place. 



The Age of the Earth and Beginning of the Life Period 



The age of the earth as a solid body affords our first in- 

 stance of the very wide discordance between physical and 

 biological opinion. Among the chief physical computations 

 are those of Lord Kelvin, Sir George Darwin, Clarence King, 

 and Carl Barus.^ In 1879 Sir George Darwin allowed 56,000,- 

 000 years as a probable lapse of time since the earth parted 

 company with the moon, and this birthtime of the moon was 

 naturally long prior to that stage when the earth, as a cool, 

 crusted body, became the environment of living matter. Far 

 more elastic than this estimate was that of Kelvin, who, in 

 1862, placed the age of the earth as a cooling body between 

 20,000,000 and 400,000,000 years, with a probability of 98,000,- 

 000 years. Later, in 1897, accepting the conclusions of King 

 and Barus calculated from data for the period of tidal stability, 

 Kelvin placed the age limit between 20,000,000 and 40,000,000 

 years, a conclusion very unwelcome to evolutionists. 



As early as 1859 Charles Darwin led the biologists in de- 

 manding an enormous period of time for the processes of evo- 



' Becker, George F., 1910, p. 5. 



