several Comets not previously computed. 4rl'9 



The Comet o/' 1433 was observed both in Europe and China. 

 In the eighth year of the period Siouen-tef eighth (intercalary) 

 moon, day Jin-tseii, a comet was seen near Thien-tsiang (6, /, 

 xBootis): the tail was about 10° in length. On day Ki-sse 

 (October 2) it entered Kouan-so (Corona BoreaUs) : it swept 

 the stars 8, jw,, i, \l/, ^ Bootis. On day Ki-mao (October 12) it 

 was seen again, entering the group of stars surrounding 

 a Ophiuchi and a Hercuhs (a Chinese constellation) : it swept 

 the star Tsin (xHerculis). The comet was seen twenty-four 

 days. The elements which I have computed from this de- 

 scription, though doubtless very uncertain, have a striking 

 similarity to those of a comet discovered by M. Montaigne in 

 1780 and calculated by Olbers. 1 place the two orbits Ijin 

 juxtaposition for the sake of easy comparison. i>' ' 



' ^ Comet of U33. ^';*^^"/f Second Comet of 1780, 



Perihelion passage. Nov. 5*]9. Greenwich Dec. 1*85139. Paris miean 

 mean time. Julian style. time. New style. 



L:"|:of&'*de??o}E-.--xofl433. . - f « «f 



Inclination 77 or 76° 72 3 30 



Log. perihelion distance 9-5166 or ^^^ 0-329. q = 0'51528. 



Motion retrograde. Retrograde. 



It is extremely desirable that we should extract as much as 

 possible from the aimals of the Chinese astronomers ; in those 

 cases where the probable identity of comets seen at intervals 

 of many hundred years can be brought to light by the aid of 

 their records, we in some measure anticipate what would 

 otherwise be the work of centuries to come. It is true that 

 these bodies can now be observed with the greatest accuracy, 

 and that the researches of modern geometers furnish us with 

 ready means of ascertaining the period of revolution when the 

 observations can be implicitly depended upon; still the Chinese 

 records enable us to search for past returns of a comet, whose 

 periodicity is suspected, and thus render it possible to carry 

 back its history to a more remote period than any European 

 observations we possess. In addition to those comets already 

 computed by Burckhardt, Pingre and myself, M. Biot's ex- 

 cellent memoir exhibits the path of several others, perhaps in 



sufficient detail to allow of rough approximations to their ele- 

 ments. W...W,,,... ..,,..... .. ,. .^.w.^., ^.,: .-. . -^.v. ... ^ ■^., 



Mr. Bishop 8 Observatory, Regent s Park, J.Tv. JCIIND. 



November 3, 1845. daili-itiqlo ybuJij^iio.J 



3bfii3oii3K JtttrJoM 



