120 SPECIAL RESULTS IN THE URANOLOGICAL PORTION 



The clusters of stars, again, are either placed solitarily in 

 the heavens, or else are closely and unequally crowded, as it 

 were in strata, in the Milky Way and in the two Magellanic 

 clouds. The most numerous, and, in respect to the annular 

 configuration of the Milky Way, the most important assem- 

 blage of " globular clusters," is in a region of the southern 

 heavens, ( 238 ) between the Corona australis, Sagittarius, the 

 tail of the Scorpion, and the constellation of the Altar 

 (E. A. 16h. 45m. 19h.) But all the clusters of stars which 

 are in or near the Milky Way are not round or globular : 

 there are several of irregular outline, less rich in stars, 

 and with not very dense centres. In many round groups 

 the individual stars are of equal, and in others of unequal, 

 magnitudes. In some rare cases they show a fine reddish 

 central star ( 23 9) ; (E. A. h. 10m., N. Bed. 56 21'). 

 How such world-islands, with their multiplicity of suns, can 

 rotate free and undisturbed, is a difficult problem in dynamics. 

 Clusters of stars and nebulae, even though it be now very gene- 

 rally assumed respecting the latter that they also consist of 

 very small but still more distant stars, yet appear to be 

 subject to different laws in respect to their local distribution. 

 The recognition of these laws will have a prominent in- 

 fluence in modifying conjectures respecting what has been 

 adventurously termed the " structure of the heavens." It 

 is also a very remarkable fact of observation, that, with the 

 same aperture and magnifying power of the telescope, round 

 nebulae are more easily resolved into clusters of stars than 

 oval ones. ( 24 ) 



Of the clusters of stars which form, as it were, detached 

 systems, I content myself with naming the following : 

 The Pleiades : doubtless recognised from the earliest 



