275 



Hence the oppositions of Ceres will be deduced as follows: 

 8 9 1 827. Sept. 26. 9^ 30' 45". Mean time at Gottingen. 

 Heliocentric longitude... 2° 58' 19"'5 



Geocentric latitude —15 41 56-4 



S "i 1829. Jan. 1. 4'^ 8' 47". Mean time at Gottingen. 

 Heliocentric longitude... 101° 3' 13"-5 



Geocentric latitude +5 56 5'5 



The mean geocentric errors in all six oppositions are con- 

 sequently : 



where the last somewhat more considerable difference answers 

 to heliocentric errors of 13" in longitude, and 7" in latitude; 

 so that it is to be hoped, even if these errors are chargeable 

 to the elements only, and not, perhaps, also partly to the per- 

 turbation caused by Saturn and Mars, which have been neg- 

 lected, that these errors will not render the finding of Ceres 

 (lilTicult for the approaching years, until the orbit shall have 

 been more accurately determined. 



The early development of the perturbations of Ceres, which 



was almost contemporary with the determination of the orbit 



itself, and the certainty, thereby obtained, of always being, 



2 N 2 for 



