248 Mr, Herschel on the 



ocean, and therefore I fliall go no farther than the gages will 

 authorifs ; but confidering the httle depth of the ftratum in 

 all thofe places which have been actually gaged, to which muft 

 be added all the intermediate parts that have been viewed and 

 found to be much like the reft, there is but little room toexpe6i: 

 a conneclion between ournebuhi and any of the neighbouring 

 ones. I ought alio to add, that a telefcope with a much larger 

 aperture than my prelent one, gralping together a greater quan- 

 tity oi light, and thereby enabling us to fee farther into fpace, 

 will be the f-arefl: means of compleating and eflablifliing the 

 arofuments that have been ufed : for if our nebula is not abfo- 

 lutely a detached one, I am firmly perl-Jaded, that an inftru- 

 ment may be made large enough to diicover the places where 

 the ftars continue onwards. A \evj bright milky nebuloficy 

 muft there undoubtedly come on, fmce the flars in a Held of view 

 will increafe in the ratio of fi\ greater than that of the cube 

 of the vifual ray. Thus, if 588 flars in a given field of view 

 are to be fcen by a ray of 497 times the diftance of Sirius ; 

 when this is lengthened to 1000, which is but little more 

 than double the former, the number of ftars in the fame field 

 of view will be no lefs than 4774 : for when the vifual i^ay r 



is giv^n, the number S of fl:ars will be = ^; where «=:r4-i; 



and a telefcope with a three-fold power of extending into fpace, 

 or with a ray of 1500, which, I think, may eafily be con- 

 flru6:ed, will give us 16096 flars. Now, thefe would not be 

 fo clofe but that a good power applied to luch an inflrument 

 might eafily diflinguifh them ; for they need not, if arranged 

 in regular Iquares, approach nearer to each other than 6^^,27; 

 but what would produce the milky nebulofity wiiich I have 

 mentioned is the numberlefs flars beyond them, which in one 



refpcdl 



