18G ASTRONOMY 



that " stellar variability is by no means an exceptional X'tenomenon, 

 but that at least one-lialf of the stars above the 7.0 magnitude vary 

 by amounts which careful observation cannot fail to detect." 



An atlas of fourteen charts accompanies the catalogue, and gives an 

 exact pictorial representation of the state of the sky at the epocli of the 

 work. Besides giving a rei)resentation of the isolated stars, the shad- 

 ings and gradations of the milky way are given with the greatest detail 

 from repeated observations and revisions. By no means the least valu- 

 able part of the work is the discussion of the course of the milky way 

 throughout the whole sky. The course of the galaxy is now, and only 

 now, known with precision. The data of this and preceding uranoine- 

 tries are discussed by Dr. Gould with reference to the question of the 

 distribution of the stars in space, starting from the assumption that, on 

 the whole, stars are equally scattered. Dr. Gould finds that there is a 

 marked excess of the stars from the first to the fourth magnitude 

 Furthermore, he finds that there is in the sky a zone or belt of bright 

 stars as marked as the milky way, and that all the bright stars are dis- 

 tributed more symmetrically with respect to this belt than with regard 

 to the milky way itself. From these facts Dr. Gould concludes that 

 "our own solar system forms a part of a small cluster distinct from the* 

 vast organization of that which forms the milky way." This cluster may 

 l^erhaps be comparable with that of the Pleiades, since by a rough esti- 

 mate it would seem to consist of about 500 stars. It is situated nearly 

 in the plane of the belt of bright stars. 



No more valuable work than this has been given to astronomy within 

 the decade; and it will be a source of pride to Americans to find such 

 important contributions coming from one of their countrymen in the 

 southern hemisphere, with which the name of Gilliss was already in- 

 dissolubly associated. 



There are no marks about the work itself which would show that it 

 was done in a community in about the state of Europe during the dark 

 ages, and it will add, not to the value of the work, but to the credit of 

 the workers, if one remembers that this is strictly the case. 



Dr. AuwERS has published, for the zone committee of the Astronom- 

 ische Gesellschaft, an important work, "Fundamental Catalog fiir die 

 Zonen-Beobachtungen am nordlichen Himmel." (Leipzig, Engelmann, 

 4to.) This catalogue of 539 stars, on which the places of all the stars 

 between — 2° and +80° Deck down to the 9th mag. inclusive will de- 

 l^end, is founded on the following systems of standard places: Pulkova, 

 1845 and 18G5 ; MS. of Pulkova Observations, 1809-'74; MS. of Bradley's 

 Stars from Greenwich Observations 183G-'72 on the system of the first 

 7-year Catalogue; Greenwich 9-year Catalogue; Harvard College Ob- 

 servatory, vol. X ; Engelmanu's Declinations, 18G6-'70 ; Leiden Declina- 

 tions, 18G4-'70. 



At the Berlin meeting of the Astronomische Gesellschaft reports on 



