Permanent Contraction of the Planetary Orbits. 95 



On the Evidence afforded by Bode's Law of a per- 

 manent Contraction of the Radii Vectores of the 

 Planetary Orbits. By Henry Wilde, F.R.S. 



{Received February jt/i, 1895.) 



In my paper on the multiple proportions of the atomic 

 weights,* in which a geometric series of planetary distances, 

 or condensations, was compared with an arithmetical series 

 of atomic weights, it was laid down as a principle of scientific 

 reasoning that, when a number of recurring instances was 

 sufficient to establish the relation of cause and effect, or, 

 in other words, the general accuracy of a law, the road to 

 further discovery lay rather in the direction of explaining 

 the anomalous departures from it, than in challenging 

 the truth of the law itself. 



Although this principle will be very generally admitted 

 by philosophic thinkers, yet, a number of specialists in the 

 natural sciences tacitly reject or openly deny it altogether. 

 The cause of this divergence of opinion between different 

 classes of thinkers and workers is not far to seek. 



Next in order of importance to the discovery of the 

 phenomenal properties of matter, is the accurate determina- 

 tion of the numerical relations subsisting among them. It 

 is from close observation of these properties and their 

 mathematical relations, that the physical sciences have 

 attained their present high state of perfection, and on 

 which their future progress will still further depend. 



Through the laborious researches of an army of scientific 

 workers, the physical constants of nature have been deter- 

 mined with a degree of accuracy which is truly marvellous. 



* Memoirs and Proceedings of the Manchester Literary and Philosophical 

 Society, 4th Series, Vol. IX. 



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