414 GLOBULAR CLUSTERS. SECT. XXXVI. 



where the stars are seen projected on each other, is one blaze of 

 light. If each of these stars be a sun, and if they be separated by 

 intervals equal to that which separates our sun from the nearest 

 fixed star, the distance which renders the whole cluster barely 

 visible to the naked eye must be so great, that the existence of 

 such a splendid assemblage can only be known to us by light 

 which must have left it at least a thousand years ago. These 

 magnificent globular or spheroidal aggregates of stars are so 

 arranged that the interior strata are more crowded and become 

 more nearly spherical as they approach the centre. A most 

 splendid object of this nature may be seen in the constellation 

 Hercules (N. 235). 



Of 131 of these magnificent objects in the southern hemisphere, 

 two of them are pre-eminently splendid. The globular cluster of 

 a Centauri is beyond comparison the finest of its kind : it is per- 

 fectly spherical, and occupies a quarter of a square degree ; the 

 stars in it are literally innumerable, crowding and densely aggre- 

 gated towards the centre ; and, as its light is not more to the 

 naked eye than that of a star of the 4th or 5th magnitude, their 

 minuteness is extreme. It has a dark hole in its centre, with a 

 bridge of stars across, a circumstance peculiar to this cluster. 



Lacaille's globular cluster, or 47 Toucani, is completely insu- 

 lated in a very dark part of the sky not far from the lesser of the 

 Magellanic clouds. The stars, which are of the 14th magnitude, 

 immensely numerous, compressed and white, form three distinct 

 stages round a centre, where they suddenly change in hue, and 

 form a blaze of rose-coloured light. One cluster consists of large 

 ruddy stars and small white ones ; another of greater beauty con- 

 sists of shells or coats of stars of the llth and 15th magnitude. 

 There are thirty globular clusters of extreme beauty collected 

 within a circular space of not more than eighteen degrees radius, 

 which lies in the part of the sky occupied by the constellations 

 Corona Australis, the body and head of Sagittarius, the tail of 

 Scorpio, part of Telescopium and Ara. The Milky Way passes 

 diametrically across the circular area in question, which gives 

 prodigious brilliancy to this part of the sky. For besides these 

 globular clusters, which all lie in the starry part, and not in the 

 dark spaces, there are the only two annular nebulse known to 

 exist in the southern hemisphere. No part of the heavens is 

 fuller of objects beautiful and remarkable in themselves, and ren- 



