350 KRETZ. 



(35) GREENWICH YEARLY RESULTS, 1887 to 

 1 894. Results of the Astronomical Observations made at the 

 Royal Observatory, Greenwich, in the years 1887 to 1894. 



The Greenwich Five-Year Catalogue includes some of these obser- 

 vations ; but the greater part of them are not as yet combined. Such 

 of my stars as were found in this series were of the latter number. 



Weights : On the preceding pages I have detailed the cata- 

 logues used in the present paper. The observations are, of 

 course, not all of the same standard of excellence. Weights 

 were assigned depending approximately on the probable error 

 of a position as given in a catalogue, the probable error of an 

 observation of unit weight being taken arbitrarily as o''.4 of arc 

 of a great circle. A table of weights was constructed on this 

 basis by Dr. Davis when engaged in a research similar to the 

 present one, and is printed in his memoir on the subject.^ To it 

 I refer. It must be remembered, however, in regard to the An- 

 nual Results, that I have regarded the observations of each year 

 as forming a separate catalogue, and have weighted them as 

 such, whereas Dr. Davis first reduced them all to 1875, and then 

 assigned a weight to the mean depending on the total number 

 of observations taken at the observatory in question. In all 

 other respects the table was used exactly as there explained. 



A few of the catalogues used by me are not included in 

 this list. They follow, together with the number of the star 

 or stars, the corresponding number of observations, and the 

 assigned weight. The figures in brackets refer to the preceding 

 list of catalogues. 



(11) GILLISS, 1840. Star no. 605, i obs.,wt. =0.1. 

 Star no. 608, 13 obs., wt. = i.o. 



(14) WROTTESLEY, 1850. Starno. 447, 5 obs., wt. = 0.5. 



(22) SAFFORD, 1865. Starno. 194, 7 obs., wt. = 2.0. 



Star no. 195, 6 obs., wt. = 2.0. 



1 ".Declinations and Proper -Motions of Fifty-Six Starsj" by Herman S. Davis, 

 Ph.D. Memoir I, of the N. Y. Academy of Sciences. Referred to &% Davis. The 

 table of weights will be found on pp. 14 to 18. 



(10) 



