ASTRONOMY. 
tcrs of fpots, with many fcaMered ones befides. Every 
one of them was certainly below the fnrface oi tlie lumi¬ 
nous diflc. * 
“ September 8, 1792. Having made a fmall fpeculum, 
merely brought to a perfect figure upon hones, without 
polifli, I found, that, by.(tilling a great part of the folar 
rays, my objeCt fpeculum would bear a greater aperture, 
and thus enable me to lee with more comfort and lefs dan¬ 
ger. The furface of the Sun was unequal; many parts of 
it being elevated, and others depreffed. This is here to 
be underftood of the (liining furface only, as the real bo¬ 
dy of the Sun can probably be feldom feen, otherwife than 
in its black fpots. It may not be impofiible, as light is a 
tranfparent fluid, that the Sun’s real furface alfo may now 
and then be perceived ; as we fee the (liape of the wick of 
a candle through its flame, or the contents of a furnace in 
the midft of the brighteft glare of it; but this, I (hould 
fuppofe, will only happen where the lucid matter of the 
Sun is not very accumulated. 
“ September 9, 1792. I found one of the dark fpots in 
the Sun drawn pretty near the preceding edge. In its 
neighbourhood I faw * great number of elevated bright 
places, making various figures: I (ball call them faculce. 
I fee thefe faculce extended, on the preceding fide, over 
about one-fixth part of the Sun; but, fo far from refem- 
bling torches, they appear to me like the fhrivelled eleva¬ 
tions upon a dried apple extended in length, and mod of 
them are joined together, making waves, or waving lines. 
By fome good views in the afternoon, I find that the reft 
of the furface of the Sun does not contain any faculcq, ex¬ 
cept a few on the following and equatorial part of the Sun. 
Towards the north and fouth I fee no faculce; there is all 
over the Sun a great unevennefs in the furface, which has 
the appearance of a mixture of fmall points of an unequal 
light; but they are evidently an unevennefs or roughnefs 
of high and low parts. 
“ September 16, 1792. The Sun contains many large 
faculce, on the following fide of its equator, and alfo fe- 
veral on the preceding fide. I perceive none about the 
poles. They feem generally to accompany the fpots, and 
probably, as the faculce certainly are elevations, a great 
number of them may occafion neighbouring depreflions : 
that is to fay, dark fpots. The faculae being elevations, 
very fatisfactorily explains the reafon why they difappear 
towards the middle of the Sun, and reappear on the other 
margin ; for, about the place where we lofe them, they be¬ 
gin to be edgeways to our view ; and, if between the fa¬ 
culae fhould lie dark fpots, they will mod frequently break 
out in the middle of the Sun, becaufe they are no longer 
covered by the fide views of thefe faculce. 
“ February 23, 1794. By an experiment juft now tried, 
1 find it confirmed thafthe Sun cannot be fo diftindly view¬ 
ed with a fmall aperture and faint darkening glalfes, as 
with a large aperture and ftronger ones ; this latter is the 
method I always ufe. One of the black fpots on the pre¬ 
ceding margin, which was greatly below the furface of the 
Sun, had, next to it, a protuberant lump of (bining mat¬ 
ter, a little brighter than the reft of the Sun. About all 
the fpots the (bining matter feems to have been difturbed, 
and is uneven, lumpy, and zig-zagged, in an irregular man¬ 
ner. I call the fpots black, not that they are entirely fo, 
but merely to diftinguifti them; for there is not one of 
them to-day which is not partly, or entirely, covered over 
with whitifh and unequally-bright nebulolity, or cloudi- 
nefs. This, in many of them, comes near to an extinc¬ 
tion of the fpot; and, in others, feems to bring on a fub- 
divifion. 
“ September 28, 1794. There is a dark fpot on the Sun 
on the following fide. It is certainly depreffed below the 
fhining atmofphere, and has (helving fides of (hining mat¬ 
ter, which rile up higher than the general furface, and are 
brighteft at the top. The preceding (helving fide is ren¬ 
dered almoft invisible, by the overhanging of the prece¬ 
ding elevations, while the following is very well expofed ; 
the fpot being apparently fuch in figure as denotes a cir- 
Vol. II. No. 76. 
cular form, viewed in an oblique direClion. Near the fol¬ 
lowing margin are many bright elevations, dole to vilible 
depreflions. The depreffed parts are lefs bright than the 
common furface. The penumbra, as it is called, about 
this fpot, is a confiderable plane,- of lefs brightnefs than 
the common furface, and feems to be as much depreffed 
below that furface as the fpot is below the plane. Hence, 
if the brightnefs of the Sun is occafioned by the lucid at¬ 
mofphere, the intenlity of the brightnefs muff be lefs 
where it is depreffed ; for light, being tranfparent, mud 
be more intenfe the more it is deep. 
“ It will now (fays Dr. Herfchel) be eafy to bring the 
refult of thefe obfervations into a very narrow compafs. 
That the Sun has an extenfive atmofphere cannot be doubt¬ 
ed ; and that this atmofphere conlifts of various elaffic 
fluids, that are more or lefs lucid and tranfparent, and of 
which the lucid one is that which rurnifhes us with light, 
feems alfo to be fully effablifhed by all the phenomena of 
its fpots, of the facuhe, and of the lucid furface itfelf. 
There is no kind of variety in thefe appearances but what 
may be accounted for with the greateft facility from the 
continual agitation which we may eaftly conceive muff take 
place in the regions of fuch extenlive elaffic fluids. It 
will be neceffary, however, to be a little more particular, 
as to the manner in which I fuppofe the lucid fluid of the 
Sun to be generated in its atmofphere. An analogy that 
may be drawn from the generation of clouds in our own 
atmofphere, feems to be a very proper one, and full of in- 
ftruCtion. Our clouds are probably decompofitions of fome 
of the elaftic fluids of the atmofphere itfelf, when fuch 
natural caufes, as in this grand chemical laboratory are 
generally at work, aft upon them; we may therefore ad¬ 
mit, that in the very extenfive atmofphere of the Sun, from 
caufes of the fame nature, fimilar phenomena will take 
place ; but with this difference, that the continual and ve¬ 
ry extenfive decompofitions of the elaffic fluids of the 
Sun are of a pliofphoric nature, and attended with lucid 
appearances, by giving out light. 
“ If it (hould be objected, that fuch violent and unre¬ 
mitting decompofitions would exhauft the Sun, we may 
recur again to our analogy, which will furnifti us with the 
following reflections. The extent of our own atmofphere, 
we fee, is (till preferved, notwithftanding the copious de¬ 
compofitions of its fluids, in clouds and falling rain; in 
flafties of lightning, in meteors, and other luminous phe¬ 
nomena ; becaufe there are frefh fupplies of elaltic vapours 
continually afeending, to make good the wafte occafioned 
by thole decompofitions. But it may be urged, that the 
cafe with the decompolition of the elaftic fluids in the fo¬ 
lar atmofphere would be very different, fince light is emit¬ 
ted, and does not return to the Sun, as clouds do to the 
earth when they defeend in (bowers of rain. To which I 
anfwer, that in the decompolition of the pliofphoric flu¬ 
ids every other ingredient but light may alfo return to the 
body of the Sun. And that the emillion of light mud 
wafte the Sun, is not a difficulty that can be oppofed to 
our hypothefis. For, as it is an evident faff that the Sun 
does emit light, the fame objection, if it could be one, 
would equally militate againft every other aflignable way 
to account for the phenomenon. 
“ There are moreover conliderations that may leffen the 
ptrefflire of this alleged difficulty. We know the exceed¬ 
ing fubtilty of light to be fuch, that in ages of time its 
emanation from the Sun cannot very fenlibly leffen the lizc 
of this great body. To this may be added, that, very 
poffibly, there may alfo be ways of reftoration to compen- 
fate for what it loft by the emillion of light; though the 
manner in which this can be brought about (hould not ap¬ 
pear to us. Many of the operations of nature are carried 
on in her great laboratory, which we cannot comprehend ; 
but now and then we fee fome of the tools with which (he 
is at work. We need not wonder that their conftruttion 
(hould be fo lingular as to induce us to cunfefs our igno¬ 
rance of the method of employing them, but we may reft 
alfured that they are not a mere lufus no/urce. I allude to 
> 4 X the 
