312 Royal Astronomical Society, 



In the meanwhile, the parabolic orbit, which seems to represent 

 est all the observations, is the following : — 



Perihelion Passage, Feb. 27*5643. 



Perihelion Distance 0-00538 



Long, of the Perihelion 277° 52' 35" 



Long, of the Node 354 48 50 



Inclination 35 56 55 



Motion retrograde. 



M. Capocci thinks it probable, however, that the comet really 

 moves in an elliptic orbit, and that it has appeared several times 

 previously. He thinks it exceedingly probable that the comets of 

 1618, 1668 and 1702, were identical with the one in question, and 

 that that of 1689 was still more clearly so, a probability which has 

 not suggested itself to any one on account of the orbit of that comet 

 inserted in the catalogue, calculated by Pingre, not being correct. 

 But M. Capocci has found that, supposing the day of the perihelion 

 passage in the year 1689 to have been December 3, the old observa- 

 tions of that comet are sufficiently well represented by the elements 

 of the present one. The physical characters of the comet coincide 

 also perfectly with those of the present one. Now this new and 

 undeniable recognition, observes M. Capocci, curiously modifies the 

 supposed period ; and to make it satisfy all the returns of which we 

 have an account, it is perhaps necessary to reduce it to one of seven 

 years nearly. He does not deny the difficulty of explaining how 

 it has happened that the comet has not been seen at its nineteen 

 former returns ; but he contends that it is less difficult to do this 

 than to account for the strange coincidence in the positions and in 

 the physical appearances of the four comets above mentioned. The 

 following is the whole series of the apparitions which may possibly 

 belong to this one and the same body : — 



1618, 1652, 1668, 1689, 1702, 1723, 1758, 1843. 



Without laying very great stress on this coincidence, he thinks it 

 proper to draw the attention of other astronomers to it, to the end that 

 each, deducing a corresponding ellipse from his own observations, may 

 either confirm or destroy the hypothesis ; a circumstance so much the 

 more important, as each may cherish the reasonable hope of seeing with 

 his own eyes, within the space of seven years, the prediction verified. 



The following is an abstract of a notice of the comet from a Ma- 

 dras paper received by the Astronomer Royal : — 



" The comet was first seen on the 2nd of March, but the only 

 part seen above the horizon was part of the tail, and that faintly. 



" On the 3rd and 4th the nucleus was distinctly visible to the naked 

 eye : the tail was divided into two distinct branches, the one long, but 

 faint, the other much shorter, but broader and much brighter. 



" On the 5th the tails had apparently united ; but on a careful 

 examination a less luminous band was detected between them. 



" On the 6th several stars were visible through the tail, which 

 near the star r Ceti was about 40' in breadth. At this part it ap- 

 peared through the telescope to consist of three luminous bands ; the 

 one next to the sun being broad and bright, the other two fainter 



