190 COSMOS. 



nebulous stars of Eratosthenes 71 and Ptolemy, the nebulotce 

 of the Alphonsine Tables in 1483, and the same of which 

 Galileo said in the Nuncius sidereus, " Sicut areolae sparsim 

 per sethera subfulgent." 



These clusters of stars are either scattered separately 

 throughout the heavens, or closely and irregularly crowded 

 together, in strata, as it were, in the Milky Way, and in the 

 Magellanic clouds. The greatest accumulation of globular clus- 

 ters, and the most important in reference to the configuration of 

 the galactic circle, occurs in a region of the southern heavens 72 

 between Corona Australis, Sagittarius, the tail of Scorpio, and 

 the Altar. (R.A. 16h. 45m.-19h.) All clusters in and near 

 the Milky Way are not, however, round and globular ; there 

 are many of irregular outline, with but few stars and not a 

 very dense centre. In many globular clusters the stars are 

 uniform in magnitude, in others they vary. In some 

 few cases they exhibit a fine reddish central star. 73 (R. A. 

 2h. 10m.; N. Decl. 56 21'.) It is a difficult problem in 

 dynamics to understand how such island- worlds, with their 

 multitude of suns, can rotate free and undisturbed. Nebulous 

 spots and clusters of stars appear subject to different laws 

 in their local distribution, although the former are now 

 very generally assumed to consist of very small, and still 

 more remote stars. The recognition of these laws must 

 specially modify the conjectures entertained of what has 

 been boldly termed the " structure of the heavens." It is 

 moreover worthy of notice that, with an instrument of equal 

 aperture and magnifying power, round nebulous spots are 

 more easily resolved into clusters of stars than oval ones. 74 



71 On the nebula in the right hand of Perseus, (near the hilt 

 of his sword,) see Eratosth. Catast., c. 22, p. 51, Schaubach. 



72 John Herschel's Observations at the Cape, 105, p. 136. 



73 Outlines, 864-869, pp. 591-596 ; Madler's Astr., s. 764. 



74 Observations at the Cape, 29, p. 19. 



