ASTRONOMY. 



[NOTES ON COM rrs. 



erer, to bar* been discovered by La Nux, at the Isle of 



>n, 

 1771. M 



on January 9th. 



April, and observed it to June 19th, It was also ob- 

 served by Dr. Maskelyne, at Greenwich, from April 14th 

 to May 30th. Its appearance was similar in brightness 

 to a star of the third magnitude, with a train varying in 

 length from 1 to 3. The orbit is supposed, with some 

 probability, to bo hyperbolic. 



177.'. BIKLA'S Cosirr. This body, of which there is no 

 doubt as to its identity with the comet of Gambart, or 

 Bie'la, was discovered by Montague, at Limoges, on the 

 8th of March. Messier observed it on three occasions, 

 on March 27th, March 30th, and April 3rd. 



1773. Discovered by Messier on the 12th of October, 

 and observed to the 14th of April, 1774. It was with 

 difficulty seen by the naked eye. 



1774. Montague discovered this comet on the 11th of 

 August, at Limoges. This was a small body, not visible 

 to the naked eye. 



177'J. The small comet of this year was discovered by 

 Bode, on January 6th, at Berlin ; and independently by 

 Messier, on January 18th, who observed it on the 17th 

 of May. 



7780. First comet. This comet was discovered by 

 Messier, on October 2Cth. 



1780. Second comet. This was discovered by Mon- 

 tague, at Limoges, on October 18th. It was also seen by 

 Olbers, on the same day. 



1781. First comet This small comet, which was not 

 visible to the naked eye, was discovered by Mechain on 

 the 28th of June. It had no tail. The diameter of the 

 nebulosity did not exceed 3' or 4'. 



1781. Second comet, discovered by Mechain on the 9th 

 of October, and observed to December 25th. On No- 

 vember 9th it was visible to the naked eye, the nebu- 

 losity being 4' or 5' in diameter, and its tail 3 or 4 in 

 K : ^: 1 1 1 . 



1783. Discovered by Pigott at York, on November 19th, 

 as a small faint body, with difficulty bearing any illumi- 

 nation of the telescope. There is little doubt as to the 

 ellipticity of its orbit, the period varying from five years 

 and ten years, in Burckhardt's two orbits. 



1784. "La Nux first observed this comet on the 15th of 

 December, 1783, at the Isle of Bourbon . At Paris, in the 

 month of January, 1784, it was visible to the naked eye, 

 with a tail from to 3 in length. 



1785. First comet discovered by Messjer and Mechain 

 on the 7th of January. It was invisible to the naked 

 eye. 



1 785. Second comet discovered by Mechain on the llth 

 of March, and observed to the 7th of April. On April 

 4th, the nucleus was visible to the naked eye, with a tail 

 l> in length. 



1786. First comet This is a well-ascertained appear- 

 ance of Encke's comet, which was discovered by Mi-chain 

 on January 17th, and only observed on two occasions. 



1786. Second comet. This body was discovered at 

 Slough, on the 1st of August 



This comet was discovered by Mechain on the 

 10th of April. It was a small luminous body, only 

 risible in a telescope. 



1788. First comet. This comet, which at its first ap- 

 pearance was not visible to the unaided vision, was dis- 

 covered by Messier on November 25th. Its brightness 

 increased so much that it was visible to the naked eye 

 on November 30th. It appeared with a train 2 or 3 in 

 length. The last observation was on December 29th, 

 when the comet had diminished considerably in bright- 



1788. Second Comet. This was discovered by Miss 

 Caroline Uenchel on December 21st It was a small 

 telescopic body, presenting, at its first appearance, a 

 nebulosity of five or six minutes in diameter. 



1790. First comet. Discovered by Miss Herschel on 

 January 7th. This was also a nebulous body, only visible 

 by the help of a telescope, and of a diameter equal to 

 about five or six minutes of arc. 



1790. Second cornet. Discovered by Mechain on Jiuiu- 



ary 9th. It appears to have been nearly similar to the 

 preceding, and visible at the sain.- tin>. 



17'.* >. Third comet. This was discovered by Miss 

 Herschel on the 18th of April. It was observed by 

 Messier from the 1st of May to the 29th of June. Its 

 brightness on the 17th of May was so great that it wan 

 visible to the naked eye ; the length of the tail varied 

 from 2 to 4. 



1792. First comet Discovered by Miss Herachol on 

 the 15th of December, 1791. It was a faint nebulous 

 body. 



1792. Second comet Discovered by the Rev. E. Greg- 

 ory on the evening of January 8th, 1793. It was a dull 

 nebulous body, with a faint appearance of tail 



1795. First comet. Discovered by Messier or Me- 

 chain on the 27th of September. 



17'.'">. Second comet Discovered by Peray on Sep- 

 tember 24th. Miss Herachol detected it on the 7th of 

 October. Burckhardt estimated its period to be twelve 

 years, which, from a revision of the elements by D' Ar- 

 rest, is improbable. The Utter astronomer makes its 

 period to be 422 yean. 



1795. Encke's comet. Discovered by Miss Herschel on 

 November 7th, and observed by Dr. Maskelyne, and 

 other astronomers, to the end of the mouth. It was a 

 round, ill-defined body, without a nucleus. 



179G. This comet was discovered by Olbers on March 

 31st. It was a very faint body, and would bear no illu- 

 mination of the field. 



1797- This comet was discovered by Bouvard on 

 August 14th. It was a nebulous body from 3' to 5' in 

 diameter. 



1798. First comet. Discovered by Messier on April 

 12th. 



1798. Second comet. Discovered by Bouvard on 

 December 6th. It was a faint body, with a slight in- 

 crease of light in the centre. 



1799. First comet Thia body was discovered by Me- 

 chain on August 7th, and visible to October. It was 

 very faint when first seen ; but at the eud of August it 

 was visible to the naked eye, with a tail about 1 in 

 length. 



1799. Second comet Discovered by Mechain on 

 December 2(ith ; it was visible to the naked eye as a 

 star of the fourth or fifth magnitude. It had a tail from 

 1 to 3 in length. 



1801. Discovered by Reissig, jun., of Cassel, on June 

 30th, and observed by Messier to July 23rd. It was a 

 small body. 



1802. Discovered by Pons, at Marseilles, on August 

 26th ; it was not visible to the naked eye. 



1804. This comet, which had neither nucleus nor tail, 

 was discovered by Pons ou March 7th. It was seen the 

 last time on the 1st of April. 



1805. (1) Encke's comet. It was visible to the naked 

 eye, and much resembled the nebula in Andromeda. It 

 was discovered by Thulis, of Marseilles, on October 19th. 

 One observer mentions its tail as being 3 in length. 



1805. (2) Biela's comet. Discovered by Pons, on 

 November 10th, as a very faint body, the nebulosity 

 scarcely bearing the slightest illumination of the ' 



1806. Discovered by Pons on the 10th of November. 

 The coma was from 5' to 7' in diameter. 



1807. Discovered by Pons on September 20th ; but it 

 appears to have been first seen eight days previously by 

 an Augustine monk in Italy. This was the finest comet 

 that had appeared since 1 769. On the 30th of Septeml -r, 

 the nucleus was equal to a star of the first magnitude. 

 Olbers, on November 7th, iiuvd the division of the tail 

 into two branches. 



1808. (2) Discovered by Pons, in Camelopardus, on 

 March 25th, and observed to the 2nd of April. 



1810. Discovered by Pons, on the 22ud of August, 

 and observed to October 8th. It was a faint and small 

 round nebulous body. 



1811. The great comet of this year, which was first dis- 

 covered by Flangergues on March 25th, and visible to tlio 

 end of October. 



The great comet of this year, so remarkable in 



