Meanwhile, in France, another and better-known mathematician had taken up the subject, and in three memoirs presented to the French Academy of Sciences in 1846, Leverrier furnished data concerning the new planet which agreed in very remarkable fashion with those furnished by Adams to Airy. The coincidence shook Airy's scepticism, and he asked Dr. Challis, director of the Cambridge Observatory, to begin a search for the planet with the large Northumberland equatorial. Challis, who had no complete charts of the region to be searched, began to make observations for the construction of a chart which would enable him to detect the planet by means of its motion. It is more than likely that had he adopted Hussey's suggestion of simply sweeping in the vicinity of the spot indicated, he would have been successful, for the Northumberland telescope was of 11 inches aperture, and would have borne powers sufficient to distinguish readily the disc of Neptune from the fixed stars around it. However, Challis chose the more thorough, but longer method of charting; and even to that he did not devote undivided attention. 'Some wretched comet,' says Proctor, 'which he thought it his more important duty to watch, prevented him from making the reductions which would have shown him that the exterior planet had twice been recorded in his notes of observations.' Indeed, a certain fatality seems to have hung over the attempts made in Britain to realize Adams's discovery. In 1845, the Rev. W. R. Dawes, one of the keenest and most skilful of amateur observers, was so much impressed by some of Adams's letters to the Astronomer Royal that he wrote to Lassell, asking him to search for the planet. When Dawes's letter arrived, Lassell was suffering from a sprained ankle, and laid the letter aside till he should be able to resume work. In the meantime the letter was burned by an officious servant-maid, and Lassell lost the opportunity of a discovery which would have crowned the fine work which he accomplished as an amateur observer. A very different fate had attended Leverrier's calculations. On September 23, 1846, a letter from Leverrier was received at the Berlin Observatory, asking that search should be made for the planet in the position which his inquiries had pointed out. The same night Galle made the search, and within a degree of the spot indicated an object was found with a measurable disc of between two and three seconds diameter. As it was not laid down on Bremiker's star-chart of the region, it was clearly not a star, and by next night its planetary nature was made manifest. The promptitude with which Leverrier's results were acted upon by Encke and Galle is in strong contrast to the sluggishness which characterized the British official astronomers, who, indeed, can scarcely be said to have come out of the business with much credit.