ON THE CONSTRUCTION OF THE HEAVENS, g9 



two different ways, we have 1 65 thoufand for each cluttering 

 collection. Now, as a more particular account of the milky- 

 way will be the fubject of a feparate paper, I fhall only ob- 

 ferve, that the above-mentioned milky appearances deferve 

 the name of cluttering collections, as they are certainly brighter 

 about the middle, and fainter near their undefined borders. 

 For, in my fweeps of the heavens, it has been fully afcer- 

 tained, that the brightnefs of the milky-way arifes only from 

 ttars ; and that their compreffion increafes in proportion to the 

 brightnefs of the milky-way. 



We may indeed partly afcribe the increafe, both of bright- 

 nefs and of apparent compreffion, to a greater depth of the 

 fpace which contains thefe ttars ; but this will equally tend to 

 fhew their cluttering condition : for, fince the increafe of 

 brightnefs is gradual, the fpace containing the cluttering ttars 

 mutt tend to a fpherical form, if the gradual increafe of bright- 

 nefs is to be explained by the fituation of the ttars. 



,\ V. Of Groups of Stars. 



From cluttering ttars there is but a fhort tranfition to groups 5. Groups of 

 of ttars ; they are, however, fufficiently diftinct to deferve a s * 

 leparate notice. A group is a collection of clofely, and almoft 

 equally comprefled ttars, of any figure or outline ; it contain s 

 no particular condenfation that might point out the feat of an 

 hypothetical central force ; and is fufficiently feparated from 

 neighbouring ttars to (hew that it makes a peculiar fyftem of 

 its own. It mutt be remembered, that its being a feparate 

 fyftem does not exclude it from the action or influence of other 

 fyftems. We are to underftand this with the fame referve 

 that has been pointed out, when we explained what we called 

 infulated ttars. 



The conftruction of groups of ttars is perhaps, of all the ob- 

 jects in the heavens, the raoft difficult to explain ; much lefs 

 can we now enter into a detail of the numerous obfervations I 

 have already made upon this fubject. I therefore proceed m 

 my enumeration. 



VI. Of Clujlers of Stars. 



Thefe are certainly the moft magnificent objects that can 6. Clutters of 

 be feen in the heavens. They are totally different from mere ftar ** 

 groups of ttars, in their beautiful and artificial arrangement : 



their 



