THE ORBIT OF NEPTUNE. 



53 



20. Corrections to the observed 2>ositions in order to render them strictly com- 

 parable with each other. 



These corrections have been derived from a comparison of the positions of the 

 ten fundamental clock stars, from y Aquilre to a Ceti inclusive, given by obser- 

 vations at the different observatories, with the adopted standard positions. The 

 standard right ascensions are those of Dr. Gould, prepared for the United States 

 Coast Survey. The declinations are those of Wolfers in the " Tabulte Reduc- 

 tionum," diminished by 0".50. Both are given in the following table : 



In reducing the Albany observations, it was found advisable to add o Piscium to 

 the number of standard stars for determining these corrections. Its assumed 

 position is 



R. A. 18GO.O. 



23 51 7.42 



Declination 1800.0. 



+ 6 



5' 17". 9 



The observed mean right ascensions and declinations of these stars, reduced to 

 the beginnings of the several years, have been compared with those derived from 

 the above table, giving the result from each star a weight proportional to the 

 number of observations when the observations were few in number, but giving 

 each result equal weight when they were numerous. Thus the following sys- 

 tematic corrections have been derived: 



