"5. If the observations of one night are not sufficient to settle these points, the enunciation of the discovery must still be made, in compliance with the third article. As soon as a second observation is made, it must be communicated in like manner with the first, and with it the longitude of the place where the discovery is made, unless it take place at some known observatory. The expectation of obtaining a second observation will never be received as a satisfactory reason for postponing the communication of the first. "6. The medal will be assigned twelve months after the discovery of the comet, and no claim will be admitted after that period. "7. Messrs. Baily and Schumacher are to decide if a discovery has been made. If they differ, Mr. Gauss, of Göttingen, is to decide. "8. Messrs. Baily and Schumacher have agreed to communicate mutually to each other every announcement of a discovery. "Altona, April, 1840." On the 1st of October, 1847, at half-past ten o'clock, P.M., a telescopic comet was discovered by Miss Maria Mitchell, of Nantucket, nearly vertical above Polaris about five degrees. The further progress and history of the discovery will sufficiently appear from the following correspondence. On the 3d of October the same comet was seen at half-past seven, P.M., at Rome, by Father de Vico, and information of the fact was immediately communicated by him to Professor Schumacher at Altona. On the 7th of October, at twenty minutes past nine, P.M., it was observed by Mr. W.R. Dawes, at Camden Lodge, Cranbrook, Kent, in England, and on the 11th it was seen by Madame Rümker, the wife of the director of the observatory at Hamburg. Mr. Schumacher, in announcing this last discovery, observes: [Footnote: "Astronomische Nachrichten," No. 616.] "Madame Rümker has for several years been on the lookout for comets, and her persevering industry seemed at last about to be rewarded, when a letter was received from Father de Vico, addressed to the editor of this journal, from which it appeared that the same comet had been observed by him on the 3d instant at Rome." Not deeming it probable that his daughter had anticipated the observers of this country and Europe in the discovery of this comet, no steps were taken by Mr. Mitchell with a view to obtaining the king of Denmark's medal. Prompt information, however, of the discovery was transmitted by Mr. Mitchell to his friend, William C. Bond, Esq., director of the observatory at Cambridge. The observations of the Messrs. Bond upon the comet commenced on the 7th of October; and on the 30th were transmitted by me to Mr. Schumacher, for publication in the "Astronomische Nachrichten." It was stated in the memorandum of the Messrs. Bond that the comet was seen by Miss Mitchell on the 1st instant. This notice appeared in the "Nachrichten" of Dec. 9, 1847, and the priority of Miss Mitchell's discovery was immediately admitted throughout Europe.