ioo Mr. Henry Wilde on a 



numbers for Neptune with the actual distance of the 

 planet* 



The latest and most uncompromising objector to Bode's 

 law is the eminent astronomical computer, Simon Newcomb, 

 who says that, " before the discovery of Neptune the agree- 

 ment was so close as to suggest the existence of an actual 

 law of distances; but the discovery of this planet in 1846 

 completely disproved the supposed law, and there is now 

 no reason to believe that the proportions of the solar system 

 are the result of any exact and simple law whatever." f 



In the opinions expressed by the eminent astronomers 

 here referred to, we see the same mental attitude towards 

 approximate laws which inclines to reject them absolutely, 

 as in the case of the law of multiple proportions in the 

 atomic weights, rather than to search for the causes of 

 differences. 



So accustomed are astronomical computers to viewing 

 the exact relations of Kepler's laws with the law of gravita- 

 tion, and the extreme refinements of measurement employed 

 in connexion with these relations, that their power of 

 forming a just estimate of probabilities becomes atro- 

 phied by disuse, to the great hindrance of the science 

 which they endeavour to advance. This habit of mind 

 is all the more deplorable in its consequences, from the 

 fact of its being unsuspected, and associated with attain- 

 ments of the highest order in men occupying important 

 positions in observatories and in seats of learning, where 

 the influence of their peculiar idiosyncrasies makes itself 

 felt through a long, course of years. % 



* Outlines af Astronomy, pp. 334 — 336. 



+ Popular Astronomy, p. 233. 



J A remarkable combination of the habit of exact observation with the 

 power of generalising is seen in the discovery, by Sir Edward Sabine, of the 

 direct connexion of the eleven-year dark sun-spot period with the same period 

 of terrestrial magnetic disturbances — a generalisation which is justly considered 

 to be one of the finest examples of inductive philosophy that has ever been 

 presented to the world. Nevertheless, a mathematician of reputation (Lord 



