326 APPENDIX. 



in which M and M &quot; have the sign of v and v &quot; ; the constant log n is 



log n = 0.0398723. 



The upper signs serve for direct, the lower for retrograde motion. 

 For the use of Table Ha instead of BARKER S Table, see Article 18 of the 

 Appendix. 



THIRD CONTROL. 



The two values of T, from it, and f&quot;, must agree exactly. 



XII. 



With T, q,n, 8 , i, I&quot;, A&quot;, &quot;, compute a&quot; and (i&quot;, and compare them with the 

 observed values. And also compute with these values the formula 



tan/?&quot; 

 ~ S m (a&quot; A&quot;) 



If this value agrees with that of m of formulas I., the orbit is exactly deter 

 mined according to the principles of Olbers s Method. That is, while it satisfies 

 exactly the two extreme places of the comet, it agrees with the observations in 

 the great circle which connects the middle place of the Comet with the middle 

 place of the Sun. 



If a difference is found, M can be changed until the agreement is complete. 



