546 Obfervations on 



The following diflances of the comet from the earth, 

 and the fun were alfo calculated : 



Di/hnces frofn the earth. 



In semidiam. of the 



earth's orbit. In miles. 



July 10th, 2.411 229,045,000 



September 1 7th, 1.512 1 43,670,000 



October I7th, 1.224 116,290,000 



November 14th, 1.591 151,145,000 



December 16th, 2.359 224,070,000 



Di/iances from the Sun. 



Semidiam. oj 



earth's orbit. Miles. 



Sept. 12th 1.0329 98,125,500 



Sept. 7th and 17th, 1.0367 98,490,000 



Sept. 2d and 22d, 1.0470 99,470,000 



Aug. 23 and Oa 1 , 1.081 103,000,000 



Aug. 8 and OcT:. 17, 1.189 113,000,000 



July 23 and Nov. 1, 1 .323 126,000,000 



July 11 and Nov. 14, 1.463 139,000,000 



June 23 and Dec. 1, 1.655 157,000,000 



June 9 and Dec. 16, 1.831 174,000,000 



May 23, 1811,and7 ^.022 192,000,000 



Jan y 1, 1812, 3 



April22 1811and7 ^.ssS 227,000,000 



reb. 1, 1812, 3 



In addition to the elements given above, one thing 

 farther is neceffary to complete the theory of the com- 

 et's motion — the period of its revolution. This is an 

 article on which much labour has heretofore been bes- 

 towed, with very little fuccefs. Two methods are ob- 

 vioufly fuggefled,for determining the time of a comet's 

 return. The moft dired; of thefe, is to derive, by calcu- 

 lation, the figure and dimenfions of the whole orbit, from 

 that fmall part of it, which is defcribed, while the comet 

 is viiible. It refults from the well known laws of grav- 

 itation, that any body, moving round the fun, and influ- 

 enced by the attraftion of no other body, muft move in 

 one of the three conic fedions, the ellipiis, the parabola, 



