244 



DETERMINATION OF AN OKBIT FROM FOUR OBSERVATIONS, [BOOK II. 



We find for the same times from the tables of the sun, 



The observed places of the planets have, the apparent obliquity of the eclip 

 tic being used, been converted into longitudes and latitudes, been freed from 

 nutation and aberration of the fixed stars, and, lastly, reduced, the precession 

 being subtracted, to the beginning of the year 1807 ; the fictitious places of the 

 earth have then been derived from the places of the sun by the precepts of arti 

 cle 72 (in order to take account of the parallax), and the longitudes transferred 

 to the same epoch by subtracting the nutation and precession ; finally, the times 

 have been counted from the beginning of the year and reduced to the meridian 

 of Paris. In this manner have been obtained the following numbers : 



, , a, a 



i , r, 



89.505162 

 178 43 38&quot;.87 

 12 27 6 .16 

 189 21 33 .71 



9.9997990 



Hence we deduce 



y =168 32 41&quot;.34, d 62 23 4&quot;.88, 

 y&quot;=173 5 15 .68, d&quot;= 100 45 1 .40, 



137.344502 



174 1 30&quot;.08 



10 8 7 .80 



235 56 .63 



0.0051376 



192.419502 

 18745 42&quot;.23 



6 47 25 .51 

 288 35 20 .32 

 0.0071739 



251.288102 

 21334 15&quot;.63 



4 20 21 .63 



345 9 18 .69 



0.0030625 



log a = 9.9526104, 

 log a&quot; =9.9994839, 



