ASTRONOMY. 
ecs tliofe near the ftar. In further confirmation of this, he 
obferves, that aclufterof liars will not fo completely account 
for the milkinefs or foft tint of the light of thefe nebulae, 
as a felf-liuninous fluid. This luminous matter feems more 
tit to produce a (lar by its condenfation, than to depend on 
the liar for its exiftence. There is a telefcopic milky way 
extending in right afeenfion from 5b. 15'. 8". to 5I1. 39'. 1". 
and in polar difiance from 87°. 46'. to 98°. 10'. This, 
Dr. Herfchel thinks, is better accounted for by aluminous 
matter, than from a collection of (tars. He obferves, that 
perhaps fome may account for thefe nebulous ftars, by 
luppofing that the nebulofity may be formed by a collec¬ 
tion of liars at an immenle difiance, and that the central 
fiar may be a near ftar accidentally fo placed ; the appear¬ 
ance however of the luminous part does not, in his opi¬ 
nion, at kll favour the fuppofition that it is produced by 
a great number of ftars ; on the other hand it mu ft be 
granted, that it is extremely difficult to admit the other 
fuppofition, when we know nothing but a (olid body that 
is felf-luminous, or, at leali, that a fixed luminary muft 
immediately depend upon Inch, as the flame of a candle 
upon the candle itfelf. See Phil. Tranf. 1791. 
In fpeaking of the planetary nebulae, Dr. Herfchel fays, 
« If we fhould fuppofe them to be lingle ftars with large 
diameters, we ffiall find it difficult to account for their not 
being brighter, unlefs we fliould admit that the intrinlic 
light of fome ftars may be very much inferior to that of 
the generality ; which, however, can hardly be imagined 
to extend to fuch a degree. We might fuppofe them to 
be comets about their aphelion, if the brightr.efs, as well 
as magnitude of their diameters, did not oppofe this idea: 
fo that, after all, we can hardly find any hypothefis fo pro¬ 
bable as that of their being nebulas; but then they muft 
conlilt of ftars that are comprelfed and accumulated in the 
higheft degree. If it were not perhaps too hazardous to 
purfue a former furmife of a renewal in what I figurative¬ 
ly called the laboratories of the univerfe, the ftars forming 
thefe extraordinary nebulae, by fome decay or wafte of na¬ 
ture being no longer fit for their former purpofes, and 
having their projectile forces, if any fuch they had, re¬ 
tarded in each others atmofphere, may rufii at laft toge¬ 
ther; and, either in fucceflion, or by one general tremen¬ 
dous ftiock, unite into a new body. Perhaps the extra¬ 
ordinary and fudden blaze of a new ftar in CalTiopeia’s 
■chair, in 1572, might poftibly be of fuch a nature. If a 
little attention to thefe bodies fhould' prove that, having 
no annual parallax, they belong moft probably to the clals 
of nebulae, they may then be expected to keep their fta- 
tion better than any one of the ftars belonging to our 
fyftem, on account of their being probably at a very 
great diftance.” Thus, then, according to Dr. Herfchel, 
the univerfe confifts of nebula r, or fyftems of innumerable 
co-lleCtions of ftars, and of Angle lucid ftars, eacli individual 
of which is a fun, not only equal, but perhaps fuperior, to 
ours ; at leaf! if the words of Mr. Nicholfon, in his Na¬ 
tural Philofophy, have any weight; for he tells us, tliat 
“ each individual fun is deftined to give light to hundreds 
of worlds that revolve about it, but which can no more 
be feen by us, on account of their great diftance, than the 
folar planets can be feeri from the fixed ftars. Yet, con¬ 
tinues he, as in this unexplored, and perhaps unexplora- 
ble, abyfs of fpace, it is no necefl’ary condition that the 
planets fhould be of the fame magnitudes as thofe belong¬ 
ing to our fyftem, it is not impollible but that planetary bo¬ 
dies may be d:(covered among the double and triple ftars.” 
In the Philofophical Trani'aCtions of 1795, Dr. Herfchel 
affects, that the fun is in reality a planet, furrounded with 
a lucid atmofphere which furnifhes its light, and is richly 
ftored with inhabitants. “ This way of conlidering the 
fun, fays he, is of the utmoft importance; and that ftars 
•are funs, can hardly admit of a doubt. Their immenfe 
•diftance would perfectly exclude them from our view, if 
the light they fend 11s were not of the folar kind. Befides, 
the analogy may be traced much farther. The fun turns 
•on its axis: fo does the ftar Algol. So alfo do the ftars 
Vol. II. No. 75. 
34'J 
called /? Lyrae, ^ Cephei, x Antinoi, » Ceti, and many 
more; moft probably all. From what other caufe can we 
fo well account for their periodical changes. ? Again, our 
fun has fpots on its furface. So has the ftar Alg'ol; and 
fo have the ftars already named ; and probably every ftar 
in the heavens. On our fun thefe fpots are changeable. 
So they are on the ftar 0 Ceti, as evidently appears from 
the irregularity of its changeable luftre, which is often 
broken in upon by accidental changes, while the general 
period continues unaltered. The fame little deviations 
have been obferved in other periodical ftars, and ought to 
be aferibed to the fame caufe. If then ftars are funs, and 
funs are inhabitable, we fee at once what an extenfive field 
for animation opens itfelf to our view. 
“ It is true that analogy may induce us to conclude, 
that fince ftars appear to be funs, and funs, according to 
the common opinion, are bodies that ferve to enlighten, 
Warm, and fuftain, a fyftem of planets, we may have an 
idea of numberlefs globes that ferve for the habitation of 
living creatures. But, if thefe funs themfelves are pri¬ 
mary planets, we may fee fome thou lands of tl cm w ith 
our own eyes ; and millions by the help of telefcopes ; 
w hen at the fame time, the fame analogical reafoning (till 
remains in full force, with regard to the planets which 
thefe funs may fupport. 
“ I may here, fays Dr. Herfchel, take notice that, from 
other conliderations, the idea of funs or ftars being merely 
the fupporters of fyftems of planets, is not abfolutely to 
be admitted as a general one. Among tire great number 
of very compreffed chillers of ftars 1 have given in my ca¬ 
talogues, there are fome which open a different view of 
the heavens to us. The ftars in them are fo very dole 
together, that, notwithftanding the great diftance at which 
we may fuppofe the drifter itfelf to be, it will hardly be 
poflible to affign any fufficient mutual diftance to the ftars 
compofing the clulter, to leave room for crowding in tliofe 
planets, for whole fupport thefe ftars have been, or might 
be, fuppofed to exift. It fhould feem, therefore, highly 
probable that they exift for themfelves ; and are, in fad, 
only very capital, lucid, primary, planets, connected toge¬ 
ther in one great fyftem of mutual fupport. And as in 
this argument I do not proceed upon conjedures, but 
have adual obfervations in view, I (Hall mention an in- 
ftance in the drifters No. 26, 28, and 35, clafs vi. of my 
catalogue of nebulre and clufters of ftars. In thefe the 
ftars are fo crowded, that I cannot conjecture them to be 
at a greater apparent diftance from each other than five fe- 
conds; even after a proper allowance for fuch ftars, as, on 
a fuppofition of a globular form of the clulter, w ill inter¬ 
fere with one another, has been made. Now, if we would 
leave as much room between each of thefe ftars as there is 
between the Sun and Sirius, we muft place thefe clufters 
42,104 times as far from us as that ftar is from the Sun. 
But, in order to bring down the luftre of Sirius to that of 
an equal ftar placed at the above-mentioned diftance, I 
ought to reduce the aperture of my twenty-feet telefcope to 
lets than the two-and-twenty hundredth part of an inch ; 
w hen certainly I could no longer expeCt to lee any ftar at all. 
The fame remark may be made with regard to the number 
of very dole double ftars, whofe apparent diameters being 
alike, and not very fmall, do not indicate any very great 
mutual diftance. From which, however, muft be deduded 
all thofe where the different diftances may be compenfated 
by the real difference in their refpedive magnitudes. 
“ To what has been faid may be added, that in fome 
parts of the milky-way, where yet the ftars are not very 
fmall, they are fo crowded, that in the year 1792, Au- 
guft 22, I found by the gauges that, in forty-one minutes 
of time, no lefs than 258,000 of them had palled through 
the field of view of my telefcope. It feems, therefore, 
upon the whole, that, in many cafes, ftars are united in 
fuch clofe fyftems as not to leave much room for the orbits 
of planets, or comets ; and that confequently, upon this 
account alfo, many ftars, unlefs we would make them 
mere ufelefs brilliant points, may themfelves be lucid pla- 
4 U nets, 
