BIOGRAPHICAL NOTICE. xxix 



" Accordingly, I found that if I simply corrected the elliptic elements, so as to satisfy 

 the modern observations as nearly as possible, without taking into account any additional 

 perturbations, the corresponding increase in the radius vector would not be very different 

 from that given by my actual theory. Hence it was that I was led to defer writing to 

 you till I could find time to draw up an account of the method employed to obtain 

 the results which I had communicated to you. More than once I commenced writing 

 with this object, but unfortunately did not persevere. I was also much pained at not 

 having been able to see you when I called at the Royal Observatory the second time, 

 as I felt that the whole matter might be better explained by half-an-hour's conversation 

 than by several letters, in writing which I have always experienced a strange difficulty. 



" I entertained, from the first, the strongest conviction that the observed anomalies 

 were due to the action of an exterior planet ; no other hypothesis appeared to me to 

 possess the slightest claims to attention. 



" Of the accuracy of my calculations I was quite sure, from the care with which they 

 were made, and the number of times I had examined them. The only point which 

 appeared to admit of any doubt was the assumption as to the mean distance, and this 

 I soon proceeded to correct. The work however went on very slowly throughout, as I 

 had scarcely any time to give to these investigations except during the vacations. 



"I could not expect however that practical astronomers, who were already fully 

 occupied with important labours, would feel as much confidence in the results of my 

 investigation as I myself did ; and I therefore had our instruments put in order, with 

 the express purpose, if no one else took up the subject, of undertaking the search for 

 the planet myself, with the small means afforded by our Observatory at St John's. 



" I remain, dear Sir, 



" Yours very respectfully, 



"J. C. ADAMS. 



"I drew up a paper for the meeting of the British Association at Southampton, but 

 did not arrive there in sufficient time to present it, as Section A closed its sittings one 

 day earlier than I expected." 



In connexion with Adams's researches on the new planet, and his omission to reply 

 to Airy's enquiry 1 , the following interesting extracts from a letter from Challis to Airy, 

 of December 19, 1846, should also find a place here. 



"In the Atheruvum of Dec. 5 there was an article on the new planet, ably and 

 fairly written in general, but so unjust with respect to Mr Adams's scientific merits, that 

 I wrote a letter to the Editor, which is in the Athenceum of to-day... There is one point 

 in the story which is in an unsatisfactory state. Why did not Adams answer your question ? 

 I know that he is extremely tardy about writing, and that he pleads guilty to this fault. 



i In 1883, when the present writer was preparing the the Astronomer Royal's letter about the radius vector, 

 obituary notice of Challis for the Royal Astronomical Adams said, "I should have done BO: but the enquiry 

 Society, in reply to a question why he had not answered seemed to me trivial." 



