Clusters and Neb idee. 209 



sures give, for 1855*448, position 15°' 54; distance 4' 22 // * 78. 

 This wonderful object, which stands as No. 1622 in H/s cata- 

 logue of 1833, and 3572 in the General Catalogue, is the leader 

 of the marvellous class of spiral nebulce of which the Earl of 

 Rosse had, up to 1850, discovered 14, with suspicions of others, 

 and concerning which he remarks, that " the question may 

 perhaps suggest itself, whether there is not something in the 

 aspect of a spiral nebula which forces upon us the conviction 

 that it is a system with an organization quite different from 

 that of any known cluster. The only answer I am enabled to 

 give to that question is, that in the exterior stars of some 

 clusters there appears to be a tendency to an arrangement in 

 curved branches, which cannot well be unreal or accidental;" 

 and he instances 5, 10, and 13 M. ; in the latter of which H. 

 had already noticed this structure. It has also been remarked 

 by Secchi among the stars of the galaxy, and was traced by 

 G. P. Bond among the wisps and streaks of the nebula in 

 Orion — a singular fact in connection with the gaseous compo- 

 sition now ascribed to it by the best observers of the day. We 

 have as yet no intelligence as regards the result of Mr. Hug- 

 gins' s examination of the Great Spiral; and it may be feared 

 that the light is too feeble for satisfactory analysis. With 

 regard to the starry appearance, which seems to have been 

 more visible to Secchi than might have been expected from 

 Lord Rosse' s remarks, we may observe that the former thinks 

 that his achromatic has more resolving power than the latter' s 

 reflectors, owing to its superb definition. It may possibly be 

 worthy of notice that, in the catalogue of 1833, H. has spoken 

 of the companion nebula as " very suddenly brightening in the 

 middle to a star," a description which does not appear in the 

 accounts of other astronomers. 



We proceed now to another celebrated object — ■ 

 30. The Dumb-Bell Nebida in Vulpecidct. 27 M. 2060 H. 

 4532 Gen. Cat. It would be difficult to find this object from 

 description, and a diagram is therefore given, including the 

 portion of the sky between Albireo (/3 Gygni) and Al Tair (a 

 Aquilce), by means of which, with a good eye and ordinary 

 finder, it may be picked up without much trouble ; especially 

 after the student has carefully noted .the four leading stars of 

 the little constellation Sagitta a, /3, 8, <y; about 3° N. of the 

 latter, inclining a very little to the E., a keen sight will catch 

 a 5-mag. star, 14 Vuljpeculce, just sf which the nebula will be 

 detected, though not readily, with a finder of 1 j inch aperture. 

 With 5|- inches and a power of 65 it is a comparatively brilliant 

 mass of luminous haze, divided into two contiguous oval lobes, 

 on either side attended with much irregular scattered light, 

 involving a 10-mag. star, p the S. end. y, who seems to have 

 vol. vin. — no. in. P 



