of new Nebulae and C Infers of Stars • ±i§ 
Would be mod condenfed, and more advanced to the maturity 
of its figure. An obvious confequcnee that may be drawn 
fro m this coniideration is, that we are enabled to judge of the 
relative age, maturity, or climax of a fidereal fyftem, from the 
difpofition of its component parts; and, making the degrees 
of brightnefs in nebulae {land for the different accumulation of 
flars in chaffers, the fame conclufions will extend equally to 
them all. But we are not to conclude from what has been 
faid that every fpherical clufter is of an equal Handing in re- 
gard to abfolute duration, fince one that is compofed of a 
thoufand ftars only, muff certainly arrive to the perfedtion of 
its form fooner than another, which takes in a range of a 
million. Youth and age are comparative expreflions ; and an 
oak of a certain age may be called very young, while a co- 
temporary fhrub is already on the verge of its decay. The 
method of judging with fome aflurance of the condition of 
any fidereal fyftem may perhaps not improperly be drawn from 
the ftandard laid down page 218; fo that, for inftance, a, 
clufter or nebula which is very gradually more comprefied and 
bright towards the middle, may be in the perfedlion of its 
growth, when another which approaches to the condition, 
pointed out by a more equal comprefiion, fuch as the nebulae 
I have called Planetary feem to prefent us with, may be 
looked upon as very aged, and drawing on towards a period of 
change, or diffolution. This has been before furmifed, when* 
in a former paper, I confidered the uncommon degree of com- 
preffion that muft prevail in a nebula to give it a planetary 
afpedt ; but the argument, which is now drawn from the 
powers that have collected the formerly fcattered ftars to the 
form we find they have affumed, muft greatly corroborate that 
fentiment* 
