THE INNER PLANETS. 89 



to discover if there was any trace of the varia- 

 tion of latitude, with the result that he brought 

 out a period of 14 months instead of 10. This 

 aroused much interest, and many prominent 

 astronomers denied Chandler's results, which 

 were announced in 1891. As a well-known 

 astronomer has expressed it, " Euler's work 

 had shown what period the motion must have, 

 and any appearance of another period must be 

 due to some error in the observations. Chandler 

 replied to the effect that he did not care for 

 Euler's mathematics : the observations plainly 

 showed 14 months, and if Euler said 10, he 

 must have made the mistake. I do not ex- 

 aggerate the situation in the least ; it was a 

 deadlock : Chandler and observation against 

 the whole weight of observation and theory." 

 It was now shown by Newcomb that Euler had 

 assumed the Earth to be an absolutely rigid 

 body, while modern investigations show that it 

 is not so. Chandler's discovery is now accepted, 

 and proves that the North Pole is not fixed 

 in position, but has a small periodic motion, 

 though never twelve yards from its mean posi- 

 tion. That the small resulting variation in the 

 position of the stars has been noticed at all 

 is a striking illustration of the accuracy of 

 astronomical observation. 



