42 cosmos. 



17 of his Catalogue) when he was making an observation of 

 Bode's Comet in 1779. Sir John Herschel was the first who 

 delineated and accurately determined its position (R. Asc. 19° 

 52' ; N. P. Decl. 67° 43'). This nebula, which is not of an 

 irregular form, first received the name of the " Dumb-bell" 

 on the application of a reflector with an eighteen-inch aper- 

 ture. (Philos. Transact, for 1833, No. 2060, fig. 26 ; Out- 

 lines, § 881.) This similarity to a dumb-bell entirely disap- 

 peared in Lord Rosse's reflector of three-feet aperture.^ (See 

 his recent important delineation, Philos. Transact, for 1850, 

 pi. xxxviii., fig. 17.) It was also successfully resolved into 

 numerous stars, which, however, continued mixed with neb- 

 ulous matter. 



The spiral nebula in the more northern of the Canes 

 Venatici was discovered by Messier on the 13th of Octo- 

 ber, 1773 (on the occasion of his discovery of the Comet), in 

 the left ear of Asterion, very near 7} (Benetnasch) in the tail 

 of the Great Bear (No. 51 of Messier, and No. 1622 of the 

 great Catalogue published in the Philos. Transact, for 1833, 

 p. 496, fig. 25). This is one of the most remarkable phenom- 

 ena in the firmament, both on account of its singular config- 

 uration, and of the unexpected transformative effect produced 

 on its appearance by Lord Rosse's six-feet speculum. In Sir 

 John Herschel's eighteen-inch reflector, the nebula presented 

 the appearance of a spherical body, surrounded by a far-dis- 

 tant ring, so that it exhibited, as it were, an image of our 

 starry stratum with its galactic ring.f But in the spring of 

 1845, the large Parsonstown telescope transformed the whole 

 into a helicine twisted coil — a luminous spiral, whose convo- 

 lutions appear unequal, and are prolonged at both extremi- 

 ties, both in the center and outward, into dense, granular, 

 globular nodules. Dr. Nichol made a drawing of this object, 

 which was laid before the meeting of the British Association 

 at Cambridge in 1845 by Lord Rosse.J But the most per- 



* Compare pi. ii., fig. 2, with pi. v. in Thoughts on some important 

 Points relating to the System of the World, 1846 (by Dr. Nichol, Pro- 

 fessor of Astronomy at Glasgow), p. 22. " Lord Rosse," says Sir John 

 Herschel, Outlines, p. 607, "describes and figures it as resolved into 

 numerous stars with much intermixed nebula." 



t Cosmos, vol. i., p. 150, and note, where the nebula, No. 1622, is 

 termed a " brother-system." 



X Report of the Fifteenth Meeting of the British Association for the 

 Advancement of Science, Notices, p. 4; Nichol, Thoughts, p. 23. (Com- 

 pare pi. ii., fig. 1, with pi. vi.) In the Outlines, § 882, we find the fol- 

 lowing passage : " The whole, if not clearly resolved into stars, has a 

 resolvable character, which evidently indicates its composition." 



