34 5 ' ASTRO 
lie neared to ns. This ftratum I (hall call that of Cancer. 
It runs £ Cancri towards the fouth, over the fixty-feventh 
nebula of the Connoi/Tance des Temps, which is a very beau¬ 
tiful and pretty-much comprefled clufter of ftars, eafily to 
be feen by any good telefcope; and in which I have ob- 
ferved above 200 ftars at once in the field of view of my 
great re Bettor with a power of 157. This clutter appear¬ 
ing fo plainly with any good common telefcope, and being 
fo near to the one which may be feen with the naked eye, 
denotes it to be probably the next in diftance to that with¬ 
in the quartile formed by 7, 0 . From the fixty-fe¬ 
venth nebula the ftratum of Cancer proceeds towards the 
head of Hydra; but 1 have not traced it farther than the 
equator. Another ftratum, which perhaps approaches 
nearer to the foiar fyftem than any of the reft, and whofe 
fituation is nearly at reCtangles with the great fidereal ftra- 
tnm in which the Sun is placed, is that of Coma Berenices, 
as 1 (hall call it. I fuppofe the Coma itfelf to be one of 
the clufters in it, arid that on account of its nearnefs it ap¬ 
pears to be fo fcattered. It has many capital nebulae ve- 
py near it : and in all probability this ftratum runs out a 
very confiderable way. It may perhaps even make the 
circuit of the heavens, though very likely not in one of 
the great circles of the fphere ; for, unlefs it lltould chance 
to interfeCt the great fidereal ftratum of the milky-way be¬ 
fore-mentioned, in the very place in which the Sun is fta- 
tioned, fuch an appearance would hardly be produced. 
However, if the ftratum of Coma Berenices (hould_ ex¬ 
tend fo far as I apprehend it may, the direction of it to¬ 
wards the north lies probably, with fome windings, thro* 
the Great Bear onwards to Caftiopeia, thence through the 
Girdle of Andromeda and the Northern Filh, proceeding 
towards Cetus; while towards the fouth it paffes through 
the Virgin, probably on to the tail of Hydra and Centau- 
rus.” 
By a continued feries of obfervations, Dr. Herfchel be¬ 
came more confirmed in his opinion; and in a fucceeding 
.paper has given a (ketch concerning the interior conftruc- 
tion of the fidereal heavens. “ That the milky-way (fays 
he) is a mod extenfive ftratum of ftars of various fizes, ad¬ 
mits no longer of the leal! doubt; and that our Sun is one 
of the heavenly bodies belonging to it, is as evident. I 
have now viewed and gauged this (hining zone in almoft 
every direction, and find it compofed of (hining ftars, whofe 
number, by the account of thofe gauges, conftantly increa- 
fes and decreafes in proportion to its apparent brightnefs 
to the naked eye. But, in order to develope the ideas of 
the univerfe that have beenfuggefted by my late obferva¬ 
tions, it will be beft to take the fubjeCt from a point of 
view at a confiderable diftance both of fpace a.nd time. 
Let us then fuppofe numberlefs ftars of various fizes fcat¬ 
tered over an indefinite portion of fpace, in fuch a man¬ 
ner as to be almoft equally diftributed through the whole. 
The laws of attraction, which no doubt extend to the re- 
nioteft regions of the fixed ftars, will operate in fuch a man¬ 
ner as mod probably to produce the following remarkable 
cffeCts : 
“ Firft, it will frequently happen, that a ftar, being con- 
fiderably larger than its neighbouring ones, will attraCt 
them more than they will be attracted by others that are 
immediately around them; by which means they will be 
in time, as it were, condenfed about a centre ; or, in other 
words, form themfelves into a clufter of ftars of almoft 
a globular figure, more or lefs regularly fo according to 
the fize and original diftance of the furrounding ftars. The 
perturbations of thefe mutual attractions muft undoubt¬ 
edly be very intricate, as we may eafily comprehend, by 
confidering what Sir Ifaac Newton has faid, Princip. lib.i. 
prob. 38, et feq. But, in order to apply this great author’s 
reafoning of bodies moving in ellipfes to fuch as are here 
for a while fuppofed to have no other motion than what 
their mutual gravity has imparted to them, we muft fup¬ 
pofe the conjugate axes of thefe ellipfes indefinitely dimi- 
aifhed, whereby the ellipfes will become ftraight lines. 
“II. The next cafe, which will happen almoft as fre= 
N O M Y. 
quently as the former, is where a few ftars, though nof 
fuperior in fize to the reft, may chance to be rather nearer 
each other than the furrounding ones; for here al(o will 
be formed a prevailing attraction in the combined centre 
of gravity of them all, which will occafion the neighbour¬ 
ing ftars to draw together ; not, indeed, fo as to form a re¬ 
gular globular figure, but, however, in fuch a manner as 
to be condenfed towards the common centre of gravity of 
the whole irregular clufter. And this conftruCtion admits 
of the utmoft variety of (liapes, according to the number 
and fituation of the ftars which firft gave rife to the con- 
denftttion of the reft. 
“ III. From the compofition and repeated conjunction 
of botii the foregoing forms, a third may be derived, when, 
many large ftars, or combined (mail ones, are lituated in 
long extended regular or crooked rows, hooks, or branch¬ 
es ; for they will alfo draw the furrounding ones fo as to 
produce figures of condenfed ftars coarfely fitnilar to the 
former, which gave rife to thefe condenfations. 
“ IV. We may likewife admit of (till more extenfive 
combinations; when, at the fame time that a clufter of 
ftars is forming in one part of fpace, there may be another 
collecting in a different, but perhaps not fardiftant, quar¬ 
ter, which may occafion a mutual approach towards their 
common centre of gravity. 
“V. In the laft place, as a natural confequence of the 
former cafes, there will be great cavities or vacancies form¬ 
ed by the retreat of the ftars towards the various centres 
which attract them ; fo that, upon the whole, there is evi¬ 
dently a field of the greateft variety for the mutual and 
combined attractions of the heavenly bodies to exert them¬ 
felves in. 
“ From this theoretical view of the heavens, which has 
been taken from a point not lefs diftant in time than in 
fpace, we will now retreat to our own retired ftation, in 
one of the planets attending a ftar in its great combination 
with numberlefs others : and, in order to inveftigate what 
will be the appearances from this contracted fituation, let 
us begin with the naked eye. The ftars of the firft mag¬ 
nitude, being in all probability the neareft, will furnifh us 
with a ftep to begin our feale. Setting off, therefore, with 
the diftance of Sirius or ArChirus, for inftance, as unity, 
we will at prefent fuppofe, that thofe of the fecond mag¬ 
nitude are at double, thofe of the third at treble, the dif¬ 
tance, &c. Taking it for granted, then, that a ftar of the 
feventh magnitude (the fmalleft fuppofed vilible with the 
naked eye) is about feven times as far as one of the fir ft, 
it follows, that an obferver who is inclofed in a globular 
clufter of ftars, and not far from the centre, will never be 
able, with the naked eye, to fee to the end of it; for fince, 
according to the above eftimations, he can only extend his 
view to about feven times the diftance of Sirius, it cannot 
be expeCted that his_eyes fhould reach the borders of a 
clufter which lias perhaps not lefs than fifty ftars in depth 
every way around him. The whole univerfe to him, there¬ 
fore, will be comprifed in a fet of conftellations richly or¬ 
namented with fcattered ftars of all fizes. Or, if the uni¬ 
ted brightnefs of a neighbouring clufter of ftars (hould, in 
a remarkable clear night, reach his fight, it will put on 
the appearance of a fmall, faint, whitifti, nebulous, cloud, 
not to be perceived without the greateft attention. Let 
us fuppofe him placed in a much-extended ftratum, or 
branching clufter of millions of ftars, inch as may fall un¬ 
der the third form of nebula already confidered. Here 
alfo the heavens will not only be richly fcattered over with 
brilliant conftellations, but a (hining zone or milky-way 
will be perceived to furroundthe whole fphere of the hea¬ 
vens, owing to the combined light of thofe ftars which are 
too fmall, that is, too remote, to be feen. Our obferver’s 
fight vvill be fo confined, that he vyill imagine this (ingle 
collection of ftars, though he does not even perceive the 
zthoufandth part of them, to be the whole contents of the 
heavens. Allowing him now the ufe of a common telef¬ 
cope, he begins to fufpeCt that all the milkinefs of the 
bright path which furrounds the fphere may be owing to 
liars. 
