460 Clusters and Nebulce. 



figure ; the largest star in that portion is s f the centre ; and 

 n of the blaze, and beyond a comparatively vacant interval, 

 there is a curved line formed by several of the brighter stars, 

 pointing a little inwards at its p extremity, as though it were 

 a portion of a large spiral. These are indeed minutiae. But 

 such minutise not merely form the distinctive character of the v 

 object, but may be important in process of time as tests of the 

 stability of a system, of whose real nature we know much less 

 than we infer. It may be to this string of stars that the 

 E. of Rosse alludes, in including the cluster among those in 

 the exterior stars of which " there appears to be a tendency to 

 an arrangement in curved branches, which cannot weli be un- 

 real or accidental. " Supposing the impression to be as accurate 

 as it is strong, the brighter stars, of which there are many scat- 

 tered in a surrounding low-power field, are not accidentally pro- 

 jected in front of and around the mass, but form a constituent 

 part of it ; and if so, we have evidence of the combination of 

 widely different magnitudes in one system, more distinct than 

 even in the case of M 3, described in our last number. With 

 a power of 450, which for such an object overpresses the light 

 of 9i in. of silver- on- glass, it is but a turbid speck. But words 

 cannot express the magnificence of the spectacle could we be 

 transported to the corresponding, or a still less distance, till 

 that u stellar swarm x> was expanded into a glittering mass of 

 hundreds of suns of various sizes, occupying a widely ex- 

 tended region of the sky. Such an object would surely force 

 from the least attentive the exclamation which may well be 

 drawn out even by the feeble approximation to such a sight in 

 a competent telescope, <c Great and marvellous are Thy works, 

 Lord God Almighty ! " 



The boundaries of Libra and Serpens are strangely tortuous 

 and intermixed in this region ; in fact this cluster never should 

 have belonged to the former, and has been boldly thrown out of 

 it by Argelander in his Uranometria. It may be worthy of 

 notice that 5 Serpentis, the guide-star to the cluster, is marked 

 by him as of 5 mag., while he gives only 6 mag. to 10 Serpentis, 

 a star intervening with a southward bearing between it and e, 

 but the two appear to me, with a beautiful field-glass, of the 

 same brightness, as they are also marked in the S. D. U. K. 

 map. The remark acquires value from Argelander's* high. 

 reputation for accuracy ; and the stars may deserve watching. 

 By way of an instructive comparison with this and similar 

 objects in respect of the varying sizes of the stellar compo- 

 nents — a point deserving of more consideration than it has 

 received — we will add Sir John Herschel's account of a glorious 

 cluster in the S. hemisphere. We have another motive in 

 doing this — that of gratifying the laudable anxiety of some of 



