CHAPTER III. 



MISAPPREHENSIONS REGARDING THE PHYSICAL THEORY 

 OF SECULAR CHANGES OF CLIMATE. — REPLY TO 

 CRITICS — Continued. 



Tables of Eccentricity. — Influence of Winter in Aphelion. — Influence 

 of a Snow-covered Surface. — Heat Evolved by Freezing. — The 

 Fundamental Misconception. — The Mutual Reaction of the 

 Physical Agents. — Explanation begins with Winter. — Herr 

 Woeikof on the Cause of Glaciation. 



Tables of Eccentricity. — Referring to my tables of 

 eccentricity of the earth's orbit, he says : — " That there 

 are from time to time such periods of great eccentricity 

 is a well-established result of the mutual gravitation 

 of the planets ; but whether the particular epochs of 

 great and small eccentricity computed by Mr. Croll 

 are reliable is a different question." I may here 

 mention that Professor McFarland, of the Ohio State 

 University, Columbus, a few years ago, undertook the 

 task of re-computing every one of the 150 periods 

 given in my tables, and he states that, except in one 

 instance, he did not find an error to the amount 

 of -001* 



" The data for this computation," continues Professor 

 Newcomb, " are the formulae of Le Verrier, worked 

 out about 1845,-f* without any correction either for the 

 later corrections to the masses of the planets or for 



* " American Journal of Science," vol. xi. p. 456 (1876). 



f Le Verrier's formulae were worked out several years before 1845. 



