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 Ruemker, the wife of the director of the observatory at Hamburg.