ASTRONOMT. 



Hence, 



.6428 A ,9848 B = 73.5 



.7071 A 1.0000 B = 80.2 



.7660 A .9848 B = 87.0 



.8191 A .9357 B = 94.1 



,8660 A .8660 B = 99.5 



.9063 A .7660 B = 104.5 



.9397 A .6428 B = 107.5 



.9660 A .5000 B = 110,2 



By adding ttte last four into Oiie, afld also the first 

 four, we get 



3.6780 A 2.7748 B = 421.7, and 

 2.9350 A 3.9033 B =: 334.8; 

 and therefore, 



A _ 3.9033 X 421. 7 2.7748 X 334.8 

 ~ 3.678 X 3.9033 2.935 X 2.7748* 



or A = 1.55'.00. 



In like manner, B 2= 1'.2 ; so that tne equation be- 

 comes, 



y = (\ 55') sin * + (l',2) sift 2 x, 



This is nearly the equation of the centre in the 

 Earth's orbit. 



In this way all the elements of any of the planetary 

 orbits may be determined simultaneously* or may 

 be corrected if they are already nearly known In 

 the construction of Astronomical Tables, the num- 

 ber of equations combined has sometimes amount- 

 ed to several thousands. 



VOL. IL P Suppose, 



