230 HERSCHEL AND HIS WORK 



my attention already in the beginning of the year 

 1774, when viewing it with a Newtonian reflector I 

 made a drawing of it, to which I shall have occasion 

 hereafter to refer : and having from time to time 

 reviewed it with my large instruments, it may easily 

 be supposed that it was the very first object to which, 

 in February 1787, I directed my 40-feet telescope. 

 The superior light of this instrument shewed it of such 

 a magnitude and brilliancy that, judging from these 

 circumstances, we can hardly have a doubt of its being 

 the nearest of all the nebulae in the heavens, and as 

 such will afford us many valuable informations. I 

 shall however now only notice that I have placed it in 

 the present order because it connects in one object the 

 brightest and faintest of all nebulosities, and thereby 

 enables us to draw several conclusions from its various 

 appearance." 1 By nebulosity or nebulous matter he 

 meant " that substance or rather those substances 

 which give out light, whatsoever may be their nature, 

 or of whatever different powers they may be pos- 

 sessed." l From a laborious examination of these vast 

 regions of visible nebulous matter, Herschel found 

 reason to conclude that the power of gravitation was 

 condensing the matter towards one or more centres, 

 which shone with greater brilliance than the rest of 

 the mass. A motion of rotation round an axis would 

 also probably result from innumerable particles press- 

 ing towards a centre, and the matter which did not 

 condense into a nucleus perhaps a star or sun 



1 Phil. Trans, for 1811, pp. 278, 279, 277, 313. "The nature of 

 diffused nebulosity is such that we often see it joined to real nebuke." 

 He means apparently gas sometimes very rare joined to matter con- 

 densed or condensing into stars. 



