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natures, from suns far more brilliant than our own Sun, to 
glistering, or merely glimmering particles, and on to strange 
luminous patches ; which, although unresolvable into stars, as 
it was thought possible they might be — exhibit a certain 
degree of coalescence, which preserves those nebulous masses 
in a definite form. That the characters of those may be 
familiarized, the drawings of four nebulae have been borrowed 
from Lord Eosse^s Memoirs, communicated to the Eoyal 
Society. Fig. 1 is a nebula described by Lord Eosse as 
having a nebulous ring, seen on the flat. Of this nebula 
twenty-one observations were made without any symptom of 
resolvability, and the only change observable between the 
years 1850 and 1861 was that the outer luminous ring was of 
unequal brightness.* * * § Fig. 2 has lateral extensions presenting 
the appearance of handles, which probably indicate a surround- 
ing nebulous ring seen edgeways. No central star has been 
detected in this nebula.f Fig. 3 is a nebula, which with a 
power of 600 appears distinctly annular. The colour of its 
fight is greenish blue ; it has no star, but is surrounded with a 
faint external annulus. J Fig. 4. This is a bright, pretty 
large, elongated annular nebula. Lord Eosse, in his descrip- 
tion of this nebula, remarks, The filaments proceeding from 
the edge become more conspicuous under increasing magni- 
fying power within certain limits, which is strikingly 
characteristic of a cluster ; still I do not feel confident that it 
is resolvable.^^§ Many of the nebulae observed by Lord 
Eosse and others, present forms far more singular than those 
which we have selected for our illustration. We may with 
advantage borrow a few descriptions from the ever graphic 
pen of Sir John Herschel.|| The nebulous group of 
Sagittarius consists of several conspicuous nebula of very 
extraordinary forms, by no means easy to give an idea of by 
mere description. One of them is singularly trifid, con- 
sisting of three bright and irregularly-formed nebulous masses, 
graduating away insensibly externally, but coming up to a 
great intensity of fight at their interior edges, where they 
enclose and surround a sort of three-forked rift, or vacant 
area, abruptly and uncouthly crooked, and void of nebulous 
fight. A fourth nebulous mass spreads like a fan or downy 
plume from a star, a little distance from the triple nebulas. 
* Eosse, “ Phil. Trans.,” 1850, p. 507, Plate xxxviii.. Fig. 15, and “ Phil. 
Trans.,” Part iii., 1861, p. 793. 
t Ibid., 1850, p. 507, Plate xxxviii.. Fig. 14. 
X Ibid., 1850, p. 507, Plate xxxviii.. Fig. 13. 
§ Ibid., 1844, p. 322, Plate xix.. Fig. 29. 
\\ “ Outlines of Astronomy,” 3rd edition, 1850. 
