230 IIKRSCHEL 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 oc< 

 hereafter to refer: and having from time to thm 

 reviewed it with my large instruments, it may < 

 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 oi 

 a magnitude and brilliancy tluit, jii'l^in^ I'mm thrsr 

 circumstance n hardly have a doubt of its 1> in ; 



the nearest of all the nebula) in tin- liravms. ami 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 objeet tin- 

 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 natmv. 

 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 mor 

 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 ] 

 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 D< i 

 He means apparently gas sometimes very rare joined to matt 

 densed or condensing into stars. 



