180 HISTORY OF ASTRONOMY. 



nounced in 1785, with, regard to the constitution of the 

 Milky Way, and which .is still connected with Her- 

 schel's name in almost all the popular treatises on as- 

 tronomy, was afterward substantially abandoned by its 

 author. 



Quite recently, M. Struve, of Pulkova, has undertaken 

 a discussion of the same subject, employing, as the basis 

 of his researches, the most extensive catalogues of stars. 

 He has determined, partly by enumeration, and partly by 

 estimation, the number of stars of each class, as far as the 

 ninth magnitude, and their distribution throughout the 

 heavens. He finds that these stars are not uniformity 

 distributed ; but that near the equator they are most 

 abundant, in the neighborhood of two points almost 

 diametrically opposed, viz., in right ascension 6h. 40m., 

 and 18h. 40m. The stars are least abundant near the 

 diameter passing through Ih. 30m., and 13h. 30m. This 

 diameter makes an angle of 78 with the preceding. The 

 diameter of greatest condensation coincides almost exactly 

 with the position of the Milky "Way ; thus proving that 

 the phenomena of the Milky "Way are intimately con- 

 nected with the distribution of the stars from the first to 

 the ninth magnitudes, or rather that the two phenomena 

 are identical. Herschel proved, in 1817, that the Milky 

 Way was fathomless, even with his telescope of 40 feet. 

 The same uncertainty respecting the limits of the visible 

 stars exists in every part of the heavens, even toward the 

 poles of the Milky Way. Hence, if we regard all the fixed 

 stars which surround the sun as forming one grand system. 



