mo, 



PHILOSOPHICAL TRANSACTIONS. 



[anno 1737. 



it difficult, in some of the latter observations, to take its place with any to- 

 lerable certainty; which is, in part, the cause of some little disagreement ob- 

 servable in the Comet's places taken from the same stars on different nights j 

 though there are likewise other irregularities that occur in this series of obser- 

 vations, which seem to arise from small errors in the assumed places of 

 the stars. 



Supposing the trajectory described by this Comet to be nearly parabolical, 

 conformable to what Sir Isaac Newton has delivered in the 3d book of his 

 Princip. Math, he collects from the foregoing observations, that the motion of 

 this Comet, in its own orbit, was direct, and that it was in its perihelion, 

 Jan. 19, 6^ 20*" equal time at London. That the inclination of the plane of 

 the trajectory to the ecliptic, was ]8°20'45". The place of the descending 

 node b 16° 22'. The place of the perihelion ^ 25° 55'. The distance of 

 4;he perihelion from the descending node 80" 27'- The logarithm of the peri- 

 helion distance from the sun 9.347960. The logarithm of the diurnal motion 

 0.938 1 88. 



From these elements, by the help of Dr. Halley's general table for Comets, 

 to which they are adapted, he computed the places in the following table; 

 which also contains the longitudes and latitudes of the Comet, calculated from 

 the observed right ascensions and declinations abovementioned, with the dif-, 

 ferences between the observed and computed places. 



From the small differences between the Comet's observed and computed 

 places, exhibited in t'ne last two columns of this table, we may reasonably 

 conclude, that the orbit, as above determined, cannot differ much from the 

 truth, and must therefore be near enough to enable future astronomers to 

 distinguish this Comet on another return, and thus to settle its period ; which 



