ASTRONOMY. 363 



work is accompanied by a map showing the distribution of known and 

 suspected variable stars. 



A catalogue of this character forms a valuable working catalogue for 

 the observer's use. By further observation suspected variation will in 

 some cases be proved to be real, and the stars claim a place in a cata- 

 logue of known variables. A claim of this kind might indeed already 

 be made in the case of Nos. 234, 455, and 635 of Mr. Gore's list. It may 

 just be mentioned in passing that the place of No. 234, U Canis Minoris 

 is incompletely given in the catalogue. Its more exact place for 1880 

 is R. A. 7^ 34°^ 49« ; Deck, + 8° 39'-5. There are other cases in which, 

 though the period is as yet indeterminate, the fact of variation and its 

 amount may be stated with some confidence. On the other hand, fur- 

 ther observation may tend to throw a doubt on the suspicion of change 

 in the case of other stars, and, as our author observes, " these must of 

 course be removed from future catalogues." In the notes to ISTo. 287, of 

 his catalogue, a Hydrse, Mr. Gore quotes remarks by Sir John Herschel, 

 Dr. Schmidt, and Dr. Gould to the effect that the supposed variability 

 of this star may possibly be due to the influence of its ruddy color on ihe 

 estimates of its brightness. Is it not possible that the effect of color on 

 estimates of magnitude as respects different observers, or the same ob- 

 server at different times, has hardly received so much attention as it de- 

 serves? 



Large as is the number of stars included in Mr. Gore's catalogue, 

 further additions might be made to it. Comparing it, for instance, 

 with the tables of suspected variables, extracted from Mr. Chandler's 

 unpublished catalogue, by Professor Pickering, and printed in his 

 "Recent observations of variable stars" in the Proceedings of the 

 American Academy, we find some thirty stars which are not included 

 in Mr. Gore's list, and it is probable that others might be found in 

 other quarters also. Indeed, the experience of most variable star ob- 

 servers would probably suggest the view that cases of slight but dis- 

 tinctly recognizable light variation are relatively numerous. 



A word in regard to No. 445 in the catalogue may possibly helj) to 

 avert the ctance of a little confusion in the future. This star was en- 

 tered as TJ Bootis in Professor Schonfield's first catalogue of variable 

 stars, but was rejected by him in his Zn-eiter Catalog. There is 

 another star called IT Bootis by Mr. Baxendell, in a paper in the Man- 

 chester Lit. and Phil. Soc. Proceedings, vol. 21, No. 11, the place of which, 

 brought up to 1880, is R. A. U^ 48°' 47« ; Deck -f 18° 10'-9. This star 

 has a period of 175-5 days, with a range of magnitude from about 13-5 

 at minimum to about 9*2 at maximum. 



In conclusion we commend to the attention of all who are interested 

 in the subject of variable stars a work the i)reparation of tvhich must 

 have entailed on the author a considerable amount of labor both as 

 compiler and observer. (Nature.) 



