Conjlruciion of the Heavens. 255 



faid to be one that has fewer marks of profound antiquity upon 

 it than the reft. To explain this idea perhaps more clearly, we 

 fhouid recoiled that the condenfation of clufters of (lars has 

 been afcribed to a gradual approach ; and whoever refiecrs on 

 the numbers of ages that muft have paft before fome of the 

 clufters, that will be found in my intended catalogue of them, 

 could be fo far condenfed as we find them at prefent, will not 

 wonder if I afcribe a certain air of youth and vigour to many 

 very regularly fcattered regions of our fidereal ftratum. There 

 are moreover many places in it where there is the greateft 

 reafon to believe that the ftars, if we may judge from ap- 

 pearances, are now drawing towards various fecondary centers, 

 and will in time feparate into different clufters, fo as to occa- 

 fion many fub-divifions. Hence we may furmife that when a 

 nebulous ftratum coniifts chiefly of nebulie of the firft and fe- - 

 cond form, it probably owes its originate what may be called ' 

 the decay of a great compound nebula of the third form ; and 

 that the fub-diviiions, which happened to it in length of time, 

 occafioned all the fmall nebulae which fprung from it to lie in a 

 certain range, according as they were detached from the pri- 

 mary one. In like manner our fyftem, after numbers of ages, 

 may very poftibly become divided fo as to give rife to a ftratum ' 

 of two or three hundred nebulas; for it would not be difficult 

 to point out fo many beginning or gathering clufters in it ( / ). 

 This view of the prelent fuLije£l throws a contiderable light ' 

 \3p0n the appearance of that- remarkable coUedion of many ■ 



{/) Mr. MiciiELL has alfo conGdered the ftars as gathered tcgerher into ' 

 groups (Phil. Tranf. vol. LVII. p. 249.) ; which idea agrees with the fish divilicn ■ 

 of our great fyftem here pointed out. He founds an elegant proof of this on • 

 the computation of probabilities, and mentions the Pleiades, the Piafepe Cancri, 

 and the nebula (or duller of liars) in the hilt of Perfcus's fword, as infrance'^. 



hu-iidreds 



