CORRESPONDENCE 109 



to be supported by Major-General Drayson's so-called " dis- 

 covery," viz., that the pole of the heavens moves in a circle 

 whose centre is 6° removed from the pole of th.e ecliptic, and 

 makes a complete revolution in a period of 31,756 years. 



With the geological facts I am not concerned. But for the 

 benefit of those of your readers who do not claim to be able to 

 express an authoritative opinion on astronomical matters, I 

 think it is desirable to point out that astronomers generally 

 do not accept Drayson's theory. Into the reasons for its 

 unanimous rejection it is not necessary to enter here. Any 

 geological conclusions, however, which are based upon it 

 should be received with caution. Even if such conclusions 

 were in accordance with purely geological evidence, it would 

 not necessarily follow that Drayson's theory was correct. 

 Astronomical and geological reasoning sometimes lead appar- 

 ently to widely different conclusions, as in the question of the 

 age of the earth. In such cases, it is reasonable to attribute 

 the divergence of view to an incomplete knowledge on one or 

 both sides of the underlying data. 



Yours faithfully, 



H. Spencer Jones, 

 Royal Observatory, Greenwich. 



