180 



SCENERY OF THE HEAVENS. 



they are resolved into clusters of stars, of which we have examples in Prsesepe, and 

 the Galaxy. 



Herschel's catalogue contains upwards of a hundred of these clusters. One of the more 

 remarkable is in the sword-handle of Perseus, a somewhat difficult object to resolve, but 

 sufficient optical aid discriminates its components, and places before us a distinct grouping 

 together of an immense number of stars, with a circlet of brighter individuals towards 

 the centre. A line carried from Algenib, the principal star in the constellation, to the 

 middle of Cassiopeia, passes over this assemblage, situate about half-way between the 

 two. The next spherical congress of which a view is given, is in Canes Venatici, dis- 

 covered by Messier in 1784, and described as a nebula without a star, brilliant and round. 



Twenty years afterwards it was assailed by Her- 

 schel with his twenty-foot reflector, and resolved 

 into a beautiful cluster of stars about 5' or 6' in 

 diameter. Its locale in space is about 11 north- 

 west of Arcturus, nearly midway on a line drawn 



from that star to Cor Caroli. Another globular 



Nebula in Pegasus. combination was found by Mavaldi in 1745. near 



e Pegasi, observed by Messier in 1764, and described as a circular nebula with a brilliant 

 star-like centre, but Herschel separated it into constituents in 1783. Taking a favourable 

 night in spring or autumn, a practised eye may discern a feeble speck between v? and 

 Herculis, two stars of the third magnitude north and south of each other, in that con- 

 stellation, t\ being about 22 nearly due west of Vega. This speck is the thirteenth 

 nebula of Messier's list, described by him as nebuleuse sans etoiles. It was observed 

 by Halley in 1714, who remarks, "This is but a little patch, but it shows itself to the 

 naked eye when the sky is serene, and the moon absent." Employing a common telescope, 

 it assumes the appearance of a small and faint cometary body, of a globular shape ; 

 but using an instrument of first rate power, it resolves into a mass of stars, whose 



number must be enormous, but apparently 

 so closely wedged together, owing to their 

 remoteness, as to present the little indivisible 

 streak of light which is scarcely perceptible 

 without optical aid. It is impossible, says 

 an assiduous observer, to give a fitting re- 

 presentation of this magnificent cluster : 

 perhaps no one ever saw it for the first time 

 through a large telescope, without uttering 

 a shout of wonder. Such spherical stellar 

 clusters are common, the individuals of each 

 being no doubt separated from one another 

 by as wide a gulf as that which exists be- 

 tween our sun and the nearest star, their 

 apparent contiguity and compression to us 

 arising from their immeasurable distance. 

 Nebula in Hercules. , ^he globular form of clusters, however, is 



by no means unvarying. There are oval shapes, while some are of very irregular 

 outline, and present a fantastic appearance. The 30 Doradus, as sketched at Paramatta 

 by Mr. Dunlop, and examined by Sir John Herschel at the Cape of Good Hope, resem- 

 bles a number of loops, forming a kind of knot at the centre like a bunch of ribbons. 

 An angular-shaped mass appears in the Twins, on a line drawn from Pollux to the middle 

 of Orion's belt, discovered by Herschel in 1783. Another, in the form of a distant flight 



