132 DETERMINATION OF ELLIPTIC ORBITS. 



For control : s s 2 = a s 2 + /3 3 2 + y 3 2 = -4 3 



Components of '" 



The computer is now to assume any reasonable values either of the 

 geocentric distances, p lt /o 2 , /o 3 , or of the heliocentric distances, r lt r 2 , 

 r 3 (the former in the case of a comet, the latter in the case of an 

 asteroid), and from these assumed values to compute the rest of the 

 following quantities : 



By equations IIIj, III'. By equations III 2 , III". By equations III 3 , III"'. 



/ 



IV. 



Calculations relating to differential coefficients. 



Components of @" x @'" Components of @"' x @' Components of @' x @" 



n /// // /// i /// / /// t 



i = V a ay 2 = y a ay 



Cl = a"^" - ^V" C 2 = a'"P - P"a' 



t // 



ay 



These computations are controlled by the agreement of the three 

 values of G. 



The following are not necessary except when the corrections to be 

 made are large : 



