€cnfirli$wn of the Hea*Oe'ns, 
0? Shifts. And, perhaps, in putting it, by the apparent fize 
of the ftars, at 600 only, I may have confiderably under-rated 
it ; but my argument, if that firould be the cafe, will be fo 
much the Wronger, Now to proceed, 
Some of thefe round nebuke have others near them, perfectly 
fimilar inform, colour, -and the diftribution of ftars, but of only- 
half the diameter; and the ftars in them feem to be doubly crowded/ 
and only at about half the diftance from each other : they are 
indeed fo fmall as not to be vifible without the utmoft attention^ 
1 fuppofe thefe miniature nebulae to be at double the diftance of 
the ftrft. An inftance, equally remarkable and inftrudtive, is 
a cafe where, in the neighbourhood of two fuch nebulae as 
have been mentioned, I met with a third, fimilar, refolvabie, 
but much frn aller and fainter nebula. The ftars of it are no 
longer to be perceived ; but a refemblance of colour with the 
former two, and its diminifhed fize and light, may well per- 
mit us to place it at full twice the diftance of the fecond, or 
about four or five times that of the firft. And yet the nebu- 
lolity is not of the milky kind; nor is it fo much as difficultly 
refolvabie, or colourleis. Now, in a few of the extended ne- 
bulas, the light changes gradually fo as from the refolvabie to 
approach to the milky kind; which appears to me an indica- 
tion, that the milky light or nebula; is owing to their much 
greater diftance. A nebula, therefore, wnofe light is perfectly 
milky, cannot well be fuppofed to be at lefs than fix or eight 
ihoufand times the diftance of Sirius ; and though the numbers 
here affirmed are not to be taken otherwife than as very coarfe 
eftimates, yet ail extended nebula, which in an oblique fixa- 
tion',, where it is poftibly foreshortened by one-half, two thirds, 
or three- fourths of its length, fubtends a degree or more in 
Liz diameter, 
