Sscr. XXXVII. CLUSTERS OF STARS. 375 



an extensive mass of stars, whose thickness is small com- 

 pared with its length and breadth ; the earth is placed 

 near the point where it diverges into two branches, and 

 it appears to be much more splendid in the Southern 

 hemisphere than in the Northern. Sir John Herschel 

 says, " The general aspect of the Southern circumpolar 

 regions (including in that expression 60 or 70 of South 

 polar distance) is in a high degree rich and magnificent, 

 owing to the superior brilliancy and large development 

 of the milky way, which, from the constellation of Orion 

 to that of Antinous, is a blaze of light, strangely in- 

 terrupted, however, with vacant and entirely starless 

 patches, especially in Scorpio, near Alpha Centauri and 

 the Cross, while to the north it fades away pale and 

 dim, and is in comparison hardly traceable. I think it is 

 impossible to view this splendid zone, with the astonish- 

 ingly rich and evenly distributed fringe of stars of the 

 3rd and 4th magnitude, which forms a broad skirt to its 

 southern border like a vast curtain, without an impres- 

 sion amounting almost to conviction, that the milky way 

 is not a mere stratum, but annular, or at least that our 

 system is placed within one of the poorer or almost 

 vacant parts of its general mass, and that eccentrically, so 

 as to be much nearer to the region about the Cross, than 

 to that diametrically opposite to it." The cluster, of 

 which our sun is a member, and which includes the 

 milky way, and all the stars that adorn our sky, must be 

 of enormous extent, since the sun is more than two hun- 

 dred thousand times farther from the nearest of them 

 than he is from the earth ; and the other stars, though 

 apparently so close together, are probably separated from 

 one another by distances equally great. In the intervals 

 between the stars of our own system and far in the depths 

 of space, many clusters of stars may be seen like white 

 clouds or round comets without tails, either by unassisted 

 vision or with ordinary telescopes ; but, seen with pow- 

 erful instruments, Sir John Herschel describes them as 

 conveying the idea of a globular space insulated in the 

 heavens and filled full of stars, constituting a family or 

 society apart from the rest, subject only to its own in- 

 ternal laws. To attempt to count the stars in one of 

 these globular clusters, he says, would be a vain task, 



