NEW FORMULA RELATIVE TO COMETS. 295 



In addition to these results, I would join the remark, that the com- 

 puted values of x„y,, z„ expressed by the preceding differential for- 

 mulae, cannot be made to agree with (e), so long as are employed the 

 above numerical quantities found for dl, d7i', and that from this and 

 other instances, I consider as defective the manner in which the first 

 and second differentials of the geocentric longitudes and latitudes are 

 determined in the method here noticed; and which, I think, should 

 not be used for determining the component velocities of a comet, or 

 the position of its orbit. 



We might now particularize further the expressions (c?) by means 

 of (25) and (26), and the consequent values of the distances r and p. 

 But our principal aim in the present paper has, we imagine, been suf- 

 ficiently attained. We intend again to resume the subject on an early 

 occasion. 



VI. — 3 V 



