CHAPTERS ON THE STARS. 319 



From what has been said the question which will first occupy our 

 attention is that of the distribution of the stars with reference to the 

 galactic plane, or rather, the great circle forming the central line of the 

 Milky Way. 



The whole sky is divided by Seeliger into nine zones or regions, each 

 20° in breadth, by small circles parallel to the galactic circle. Eegion I. 

 is a circle of 20° radius, whose center is the galactic pole. Eound this 

 central circle is a zone 20° in breadth, called Zone II. Continuing the 

 division, it will be seen that Zone V. is the central one of the Milky 

 Way, extending 10° on each side of the galactic circle. 



The condensed result of the work is shown in the following table: 



Column 'Area' shows the number of square degrees in each region, 

 so far as included in the survey. It will be remarked that the cata- 

 logues in question do not include the whole sky, as they stop at 24° 

 S. Dec. 



Column 'Stars' shows the number of stars to magnitude 9.0 found 

 in each area. 



Column 'Density' is the quotient of the number of stars by the area, 

 and is, therefore, the mean number of stars per square degree in each 

 region. In column 'D' these numbers are corrected, for certain anom- 

 alies in the magnitudes given by the catalogues, so as to reduce them to 

 a common standard. 



Area. 



Region. Degrees. Stars. Density. D. 



1 1,398.7 4,277 3.06 2.78 



II 3,146.9 10,185 3.24 3.03 



III 5,126.6 19,488 3.80 3.54 



IV 4,589.8 24,492 5.34 5.32 



V 4,519.5 33,267 7.36 8.17 



VI 3,971.5 23,580 5.94 6.07 



VII 2,954.4 11,790 3.99 3.71 



VIII ...1,790.6 6,375 3.56 3.21 



IX 468.2 1,644 3.51 3.14 



A study of the last two columns is decisive of one of the fundamental 

 questions already raised. The star density in the several regions in- 

 creases continuously from each pole (regions I. and V.) to the galaxy 

 itself. If the latter were a simple ring of stars surrounding a spherical 

 system of stars, the star density would be about the same in regions 

 I., II. and III., and also in VII., VIII. and IX., but would suddenly in- 

 crease in IV. and VI. as the boundary of the ring was approached. 

 Instead of such being the case, the numbers 2.78, 3.03 and 3.54 in the 

 north, and 3.14, 3.21 and 3.71 in the south, show a progressive increase 

 from the galactic pole to the galaxy itself. 



The conclusion to be drawn is a fundamental one. The universe, 

 or, at least, the denser portions of it, is really flattened between the 



