130 SPECIAL RESULTS IN THE URANOLOGICAL PORTION 



formation . Thomas "Wright of Durham, ( 258 ) Kant., Lambert, 

 and at first also William Herschel, were inclined to regard 

 the form of the Milky Way, and the apparent accumulation 

 of stars in it, as consequences of the flattened form and 

 unequal dimensions of the " world-island" (sidereal stratum) 

 in which our solar system is included. The hypothesis of 

 equal magnitude and equable distribution of fixed stars has 

 recently been shaken on many sides. The bold and able 

 investigator of the heavens, William Herschel, declared 

 himself, in his last work, ( 259 ) decidedly in favour of the 

 assumption of a ring or annulus of stars, which assumption 

 he had combated in a treatise in the year 178 k. Recent 

 observations have favoured the hypothesis of a system of 

 detached concentric rings. The thickness of these rings 

 appears to be very unequal, and the several strata whose 

 united stronger or fainter light we receive, are doubtless 

 situated at very different heights, i. e. very different distances 

 from us : but the relative brightness of the several stars, 

 which we estimate as being from the 10th to the 16th mag- 

 nitude, cannot be regarded as such a measure of their relative 

 distances, as could enable us to derive from thence a satis- 

 factory numerical ( 26 ) determination of the radii of the 

 respective spheres of distance. 



In many parts of the Milky Way, the space-penetrating 

 power of instruments is sufficient to resolve the star- clouds, 

 and to enable us to see single luminous points projected 

 on the dark starless regions of celestial space. In such case 

 we really look through into free and open space. " It leads us/' 

 says Sir John Hersthel, " irresistibly to the conclusion, that in 

 these regions we see, fairly through the starry stratum." ( 261 ) 

 In other regions we see, as through openings and fissures, 



