OEBIT ELEMENTS COMET I., 1899, (SWIFT) 



187 



Declination. 



Normals 



Date 1899. 



S 



K 



db 



Weight 

 P 



I. 



March 6 



O 1 II 



- 25 5 14-2 



O t II 



- 25 5 25 



- 11-7 



13 



II. 



16 



- 12 19 49-3 



- 12 19 34-3 



- 150 



25 



III. 



28 



- 1 23 471 



- 1 23 41-6 



- 55 



4 



IV. 



May 55 



+ 26 17 297 



+ 26 17 28-4 



+ 13 



9 



V. 



265 



+ 55 40 41-9 



+ 55 42 398 



- 1179 



5 



VI. 



June 12 



+ 40 46 47-9 



+ 40 45 43-1 



+ 64 8 



12 



VII. 



July 4 



+ 18 42 53-6 



+ 18 42 1-6 



+ 52-0 



9 



VIII. 



14 



+ 13 37 471 



+ 13 36 54-2 



+ 529 



4 



In the foregoing tables the right ascension a , and the declina- 

 tion 8 have been deduced from the combination of the observations 

 as already explained. The values of a c 8 C being computed from 

 the elements II. 



Before introducing the values of da into the equations of con- 

 dition, they have been changed into seconds of arc, also multiplied 

 by cos 8. 



liquations of Condition. — If represent any co-ordinate of the 

 place of the comet computed from assumed elements of the orbit, 

 then in this discussion 



0=/(o, ft, c, T,q,e.) 

 The equations of condition will therefore take the form 



cos 8da = cos 8 — — da) + cos 8 _ — d$l cos 8 de 



do) dQ. de 



j$ dS j , d8 j o d8 -. 



do = — — doi + - — d9. de 



dco d& de 



The formulae for computing the differential coefficients in these 

 equations may be easily deduced by differentiating the various 

 equations that determine the position of the comet. 



In the equations of condition the quantities dco, d&, dc, are to 

 be determined in seconds of arc; so that the equations may be 

 homogeneous, the coefficients of the terms containing dT, dq, de, 

 have been divided by sin 1"; they have also been multiplied by 

 10~ 4 , 10~ 6 , 10~ 6 respectively; this has been done as a matter of 

 convenience for the numerical reduction. 



