166 



Astronomical and Nautical Collections 



In the above the comets' longitudes, and latitudes by obser- 

 vation are corrected for parallax and aberration, and the longi- 

 tudes are reckoned from the mean equinox. 



The faintness of the light of the comet prevented the continu- 

 ance of exact observations by the meridian instruments, as the 

 light barely sufficient for illuminating the \vires entirely effaced 

 the light of the comet. 



The following very late observations, by Dr. Olbers, made at 

 Bremen, have been compared by Dr. Brinkley with the above 

 elements. 



Nothing in the above indicates that any elliptic orbit, that 

 could be found, would be more to be depended on than a pa- 

 rabolic one ; and it may be thought useless to endeavour to 

 correct the elements, so that the very small errors exhibited 

 may disappear, because the extent of the errors of observation 

 in September and October, when the comet was so exceedingly 

 faint must be uncertain. It was rather an object to ascertain 

 the degree of precision that could be attained by the elements 

 deduced from early observations near together. 



The correctness of the elements, from the observation of the 

 4th, 5th, and 6th of July, deduced by M, Laplace's method by 

 an exact computation, may be considered worthy of notice, as 

 tending to shew the value of that method when applied to exact 

 observations. They give the perihelion distance rr 0,3397, and 

 the time of passing perihelion, June 27"* 15'' 5' 28" for the first 

 approximation. 



Dr. Brinkley, as soon as he had made these observations, 

 computed the elements by M. Laplace's method, merely to ob- 

 tain the outlines of the orbit, and with only a few places of 

 fio'ures. Those elements appeared in the Dublin Journal of 



