512 Prof. G. B. Airy on the History of the Discovery of 



suggested by a theory, which, fruitful as it has been, we may 

 almost venture to call fanciful. Astraea was found, in the 

 course of a well-conducted re-examination of the heavens, ap- 

 parently contemplating the discovery of a new planet as only 

 one of many possible results. But the motions of Uranus, 

 examined by philosophers who were fully impressed with the 

 universality of the law of gravitation, have long exhibited the 

 effects of some disturbing body : mathematicians have at length 

 ventured on the task of ascertaining where such a body could 

 be; they have pointed out that the supposition of a disturbing 

 body moving in a certain orbit, precisely indicated by them, 

 would entirely explain the observed disturbances of Uranus : 

 they have expressed their conviction, with a firmness which I 

 must characterise as wonderful, that the disturbing planet 

 would be found exactly in a certain spot, and presenting ex- 

 actly a certain appearance ; and in that spot, and with that 

 appearance, the planet has been found. Nothing in the whole 

 history of astronomy can be compared with this. 



The principal steps in the theoretical investigations have 

 been made by one individual, and the published discovery of 

 the planet was necessarily made by one individual. To these 

 persons the public attention has been principally directed ; 

 and well do they deserve the honours which they have received, 

 and which they will continue to receive. Yet we should do 

 wrong if we considered that these two persons alone are to be 

 regarded as the authors of the discovery of this planet. I am 

 confident that it will be found that the discovery is. a conse- 

 quence of what may properly be called a movement of the 

 age; that it has been urged by the feeling of the scientific 

 world in general, and has been nearly perfected by the colla- 

 teral, but independent labours, of various persons possessing 

 the talents or powers best suited to the different parts of the 

 researches. 



With this conviction, it has appeared to me very desirable 

 that the authentic history of this discovery should be published 

 as soon as possible; not only because it will prove a valuable 

 contribution to the history of science, but also because it may 

 tend to do justice to some persons, who otherwise would not 

 receive in future times the credit which they deserve. And 

 as a portion of the history, I venture to offer to this Society 

 a statement of the circumstances which have come to my own 

 knowledge. I have thought that I could with propriety do 

 this, not because I can pretend to know all the history of the 

 discovery, but because I know a considerable part of it ; and 

 because I can lay claim to the character of impartiality to this 

 extent, that, though partaking of the general movement of the 



