1840-50] ROYAL ASTRONOMICAL SOCIETY 93 to communicate the concluded position in 1845 September to Challis, and in October of the same year to Airy. No one else knew it ; Adams told nobody, neither did Challis, neither did Airy, and as far as the Society was concerned nothing happened until the November meeting of the following year. "J. C. Adams, Esq., B.A., Fellow and Assistant Tutor of St. John's College, Cambridge," was balloted for, and duly elected a Fellow of the Society in 1845 November. Previous to that he had contributed, in 1844 January, a paper on " Elements of the Comet of Faye," communicated by Prof. Challis, where, after computing an elliptic orbit, " the author suggests that the comet may, perhaps, not have been moving long in its present orbit, and that, as in the case of the comet of 1770, we are indebted to the action of Jupiter for its present apparition " ; and proceeds to show that the planet and comet must have made a near approach so recently as the year 1840. Not a bad first paper, and one that might have drawn some attention to its author. In 1846 April he must have attended the meeting, for he " presented a diagram showing the relative positions of the heads of Beila's comet, and deducing the velocity of the smaller head, finds that its periodic time is 8-48 days longer than the periodic time of the larger." Le V errier* s Publication. In 1846 June, Le Verrier published the paper which was the culmination of his investigations upon Uranus, and in which he produced the position of a disturbing planet that would account for the unexplained errors, agreeing in the closest possible way with that which Adams had assigned. It is an extra- ordinary thing that Adams did not seize the occasion to make some announcement of his own parallel, completer, and earlier determina- tion. But Adams was in some respects very immature, and all his life was beset by a peculiar reluctance to performing any ordinary conclusive act, like publishing a paper or even writing a letter. The same cannot be said of Airy. He was immensely struck with Le Verrier's paper. He wrote to him at once to say so, and at the same time put to him his famous poser, his experimentum crucis, of the explanation of the errors in the radius vector of Uranus by the same means, which he had also put to Adams, and to which Adams had not sent a reply. The singular thing about this letter is that it did not contain a single word, a hint, that Airy had already had for seven months past, in a pigeon-hole at Greenwich, identi- cally the same explanation of the anomalies of Uranus in consider- ably greater completeness. It would have interested Le Verrier vastly to know it. It would have prevented the resentment and the charge of disingenuousness which was, not unnaturally, the first feeling which the French expressed on the introduction of Adams's name at a later date. One wonders what Airy proposed
