6 Wilde, New Binary Progression of Plmietary Distances. 



19. It will be further observed that, while the plus and 

 minus differences in the distances are irregular in amount, 

 they are rectified by the mutual attraction of the planetary 

 bodies among themselves, to effect an approximate ratio 

 of equality between the binary progression of the distances, 

 shown in columns i and 4, and those derived from 

 observation. 



20. Turning now to the anomalous departure of the 

 distance of Neptune from the binary progression of 

 distances of the other members of the solar system ; it 

 will readily be admitted that, had the agreement between 

 the numbers of the binary progression and the observation 

 distances, as shown in the table, been absolute, the 

 outstanding minus difference of the distance of Neptune, 

 I9'4I0, would have still remained an exception to the law. 



21. In my former paper on the multiple proportions of 

 the atomic weights, it was laid down as a general principle 

 of philosophic 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 was in the direction 

 of explaining the anomalous departures from it, than in 

 challenging the truth of the law itself* 



22. That the distance of Neptune, at the genesis of its 

 history', was the first and exact term of the binary 

 progression is an inference justly to be drawn from the 

 like progression observable in the distances of the other 

 planetary bodies, and it was on this same distance (38'4) 

 that Adams, in 1845, based his first determination of the 

 then unknown planet. 



* Manchester Memoirs, vol. 39, p. 7 1, 1895. 



