Latitudes of Montjouy and Barcelona, 



247 



In reducing these declinations to the 1st January, 1794, 

 which is the epoch nearly of M. M^chain's observations, I have 

 computed the precession by the formula at length, employing the 

 constants determined by M. Bessel, in a memoir published in 

 the * Connoissance des Tems ' for 1829. I thus obtain,- — 



Such are the errors of the declinations employed in the 

 * Base du Systeme M^trique.' In recalculating the latitudes 

 with them by the usual method of absolute zenith distances, I 

 have computed the apparent places for each day of observation, 

 by employing 20",255 for aberration, and 18'',036 for nutation. 



Lastly, I have verified the calculations of refraction, and the 

 reduction of the zenith distances ; but in these I have found no 

 other corrections required in the published account, than of 

 several typographical faults, which, however, veiy rarely occur 

 in any of the definitive results. 



The following tables contain the series for each star recalcu- 

 lated. 



