OBSERVATIONS WITH THE ZENITH TELESCOPE. 



291 



Weights. 



In case of the Right Ascensions the weights have been taken from Auwers' values, 

 Astronomische Nachrichten, Bd. 151, for all authorities found there. For other cases the 

 attempt has been made to conform as closely to this system as practicable. 



For the Declinations the system of weights is nearly the same as that given by 

 Davis.* The most noticeable differences between the weights here employed and those of 

 Newcomb are, first, the greater value assigned by Newcomb to the Poulkova and Wash- 

 ington catalogues ; and second, in general the greater increase in weight corresponding to 

 an increase in the number of observations. This last feature is not usually very con- 

 spicuous in the present discussion, as there are comparatively few cases where the number 

 of observations is large. For the purpose of comparison the weights assigned by New- 

 comb to the authorities employed in the above example are given below, together with 

 such as are given by Bossf in connection with his investigation. 





1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



ll 



12 



13 



14 



15 



1G 



17 



18 



19 



20 



21 



22 



23 



24 



25 



26 



27 



Wght. hero used 



.0 



.3 



.0 



.0 



1.0 



.5 



.5 



.3 



.5 



3.0 



.0 



3.0 



2.0 



2.0 



2.0 



1.0 



1.5 



2.0 



1.0 



1.0 



1.0 



1.5 



.3 



1.5 



2.0 



1.0 



3.0 



Newcoml) 



.5 







.4 



1.0 











3.0 





4.0 







5.0 



1.5 



2.5 

















2.5 





2.0 



Boss 





.1 





.3 



.8 



.2 





.0 



.3 



1.5 





2.5 



.0 



1.0 



3.0 



1.0 



.7 



3.0 



1.5 



















This comparison will illustrate the different conclusions which have been reached as 

 to the relative merits of some of the authorities. It is not claimed that the weights here 

 employed are in all cases the best, but the effort has been made to follow a consistent 

 system throughout in order to reach results which shall be so far as possible 

 homogeneous. 



The Star List. 



The list of 254 latitude stars which follows includes 74 which are found in New- 

 comb's new Fundamental Catalogue. The places of these have been taken directly from 

 that publication, applying the reduction to Auwers' system as explained below. Polaris 

 is an exception, the position being taken without change from Newcomb. There are also 

 three stars given in Davis' paper before referred to. — The Declinations and Proper 

 Motions of Fifty-six Stars — the declinations of these have been taken from that publication. 



The coordinates of the remaining stars — 180 right ascensions and 177 declinations 

 — have been derived as explained in the preceding pages. 



As Newcomb's system is no doubt preferable to that of Auwers' for the reason that 



* Declinations and Proper Motions of Fifty '-six Stars, pages 14-18. 



f Declinations of the Fixed Stars, Report of the IT. S. Northern Boundary Commission, Appendix ii. 



