MICROMETER OBSERVATIONS. FINAL EQUATIONS. 



497 



December 9. Distances of limbs after Ingress, measured with the double- 

 image micrometer 



[It does not appear that the value of tlic micrometer-scale has been ascertained, and the observa- 

 tions above, as a mass, are useless. If it is desired to utilize only the earlier observations, a. value 

 sufficiently accurate may be found from comparison of the earlier with the later, referring also to 

 the co-efficient of 8 t in the final equation. G. B. A.] 



For the Greenwich sidereal time, 7 h . 29 m . 41 S '3, Major Tupman has computed 

 the final equation as follows : 



Interpolating for the Greenwich sidereal time, 7 h . 29 m . 41 S '3, the N. P. D. 

 and Differential R. A. of Sun and planet, and computing from these elements 

 the Tabular Distance of centers (15'. 38"'25 "-0319 3 t + "'0141 3 ), and 

 equating this with the interpolated distance between centers or difference of 

 semidiameters (15'. 45"'38 + 3 R 3 r) we obtain the final equation 



+ 7"-i3 = + -0141 8 + -6174 S R.A. -7429 8 N.P.B. o"-o3ig S t % 11 + 8 r. 



The equations for the Greenwich sidereal times 7 h . 29 m . 40 s- 2 and 

 7 h . 29 m . 45 S> 2 will be found by making 3 t = 1-1 and -f 3'9 respectively. 



[G. B. A.] 



3s 2 



