/ 
a 4 S Mr. Herschel on the 
ocean, and therefore I fhall go no farther than the gages will 
authorife ; but confidering the little depth of the ftratum in 
all thofe places which have been actually gaged, to which mud 
be added all the intermediate parts that have been viewed and 
found to be much like the reft, there is but little room toexpeft 
a connection between our nebula and any of the neighbouring 
ones. I ought alfo to add, that a telefcope with a much larger 
aperture than my prelent one, grafping together a greater quan- 
tity of light, and thereby enabling us to lee farther into Ipace, 
will be the fureft means of compleating and eftablilhing the 
arguments that have been ufed : for if our nebula is not abfo- 
lutely a detached one, I am firmly perfuaded, that an inftru- 
ment may be made large enough to difcover the places where 
the ftars continue onwards. A very bright milky nebulofity 
muft there undoubtedly come on, fince the ftars in a field of view 
will increafe in the ratio of n\ greater than that of the cube 
of the vifual ray. Thus, if 5 B 8 ftars 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 ray r 
is given, the number S of ftars will be — ^ ; where n = r+ 1; 
and a telefcope with a three-fold power of extending into fpace, 
or with a ray of 1 500, which, I think, may eafily be con- 
ftrudted, will give us 16096 ftars. Now, thefe would not be 
fo clofe but that a good power applied to fuch an inftrument 
might eafily diftinguilh them ; for they need not, if arranged 
in regular fquares, approach nearer to each other than 6 7/ ,27 ; 
but what would produce the milky nebulofity which I have 
mentioned is the numberlefs ftars beyond them, which in one 
refpedl 
