S U N 
Sir Ifaac Newton hath made it probable, thdt the great 
comet in the year 1680, in its, perihelion, went fo near 
the Sun, as that it acquired a heat, which would not 
entirely go oft in 50,000 years ; whence we may guefs, 
that if the Sun and fixed ftars be only collections of 
denfe and folid matter, like the planets, but heated 
to a very intenfe degree, they may be many millions 
of years without lofing any confiderable part of their 
heat. 
According to Caflini, the Sun’s diftance from the earth 
is 172,800,000 Englifh miles. 
As for the annual motion of the Sun round the earth, 
it is eafily fhewn by aftronomers, that the annual mo- 
tion of the earth will occafion fuch an appearance. 
A fpeCtator in the Sun would fee the earth move from 
weft to eaft, for the fame realon that we fee the Sun 
move from eaft to weft, and all the phenomena re- 
fulting from this annual motion, in which foever of 
the bodies it be, will appear the fame from either. 
As to the nature, properties, and figure of the Sun, 
&c. 
1. As the folar fpots are found fometimes to ftay three 
days longer behind the Sun than they fpend in paffing 
over the hemifphere vifible to us, we eafily deduce 
that they do not adhere to the furface of the Sun, but 
are at fome diftance therefrom. 
2. As the fpots frequently rife and vanifii even in the 
midft of the Sun’s difk, and undergo feveral changes, 
both with regard to bulk, figure, and denfity, it fol- 
lows, that they frequently rife, de novo, about the Sun, 
and are again difiipated. 
3. Hence it fhould follow, that they are formed out 
of the exhalations of the Sun, and are no other than 
folar clouds. 
4. Since then exhalations proceeding from the Sun 
rife above him, and ftop at a certain altitude, it is 
evident there is fome fluid encompaffing the Sun to 
urge the exhalations to rife, and this fluid muft be 
denfer at bottom, and rarer at top, like our atmo- 
fphere. 
5. Since the fpots frequently difiolve and difappear 
in the middle of the Sun’s difk, the matter of the fpots, 
that is, the folar exhalations, fall back again to the 
Sun ; whence it follows, that there muft arife vari- 
ous alterations in the Sun’s atmofphere, and the Sun 
himfelf. 
6. Since the revolution of the fpots round the Sun is 
found very regular, and likewife very near the Sun, it 
follows, that they do not revolve round the Sun, but 
that the Sun, together with his atmofphere, wherein 
the maculae are, move round their common axis in 
an interval of about twenty-feven days ; and hence it 
is, that the fpots near the limb, being viewed ob- 
liquely, appear narrow and long. 
7. Since the Sun, in every fituation, appears like a 
circular difk, its figure, as to fenfe, muft be fphe- 
rical, though it is really fpheroidical. 
8. That the fubftance of the Sun is fire, is thus 
proved : the Sun fhines, and his rays, collected by 
concave mirrors, or convex lenfes, burn, confume, 
and melt the moft folid bodies, or elfe convert them 
into afhes or glafs. 
Wherefore, as the folar rays are diminiflied by their 
divergency in a duplicate ratio of the diftances reci- 
procally taken, it is evident that their force and ef- 
fect is the fame when collected by a burning lens or 
mirror, as if we were at fuch a diftance from the Sun 
where they were equally denfe. The Sun’s rays there- 
fore, in the neighbourhood of the Sun, produce the 
fame effeCts as might be expeCted from the moft 
vehement fire ; confequently, the Sun is of a fiery 
fubftance. 
Hence it follows, that its furface is every where fluid, 
that being the condition of flame. 
Indeed it is not abfolutely determined, whether the 
whole body of the Sun be fluid, as fome think, or 
folid, as others ; but as there are no other marks, 
whereby to diftinguifh fire fromother bodies, but light, 
heat s a power of burning, confirming, melting, cal- 
cining, and vitrifying, we do not fee what fhould hin- 
S U N 
der, but that the Sun may be a globe of fire like 
ours, invefted with flame. 
9. Since the maculae are formed out of the folar ex- 
halations, it appears, that the Sun is not pure fire, 
but that there are heterogeneous particles mixed along 
with it. 
Some make the mean diftance of the Sun from the 
earth 7490 diameters of the earth, others 10,000, 
others 12,000. 
The Sun, according to that excellent chemift, the 
younger Lemery, feems to be no other than a huge 
mafs, or collection of the matter of fire or light, 
though fo placed as to dilable it to aCt on bodies here 
on earth, otherwife than by one of thefe two ways : 
firft, by emanations or emiflions of his own fubftance 
tranfmitted hither ; but this hypothefts being fubjeCt 
to great difficulties, and not fufficiently anfwering to 
certain phtenomena, recourfe is had to another, which 
fuppofes trains of fire or light, difpofed in all the in- 
terftices of the grand expanle of air and tether be- 
tween the Sun and us ; and that thefe trains are made, 
to aCt on terreftrial bodies, by their being vigoroufty 
driven or impelled toward fuch bodies, by the imme- 
diate aClion of the Sun thereon. 
Thefe trains, in effeCt, may be efteemed as a fort of 
little Suns prolonged, but always depending on the 
great Sun, as the fource of their motion and aCtion 
on bodies ; it is thofe that form the rays of light ; 
they do not, in point of matter, differ from the fub- 
ftance of the Sun himfelf, but only in this, that the 
fame thing is more copious in one cafe than the other. 
In the Sun we may fuppofe the matter of light more 
abundant than in the focus of our largeft burning- 
glaffes. Thus from the vehement aCtion of the rays 
of the Sun collected in fuch glafs, we learn what ufe 
the air, interpofed between the rays of light, is 
of in tempering their aCtion, and rendering it more 
fupportable, fince, without fuch medium, inftead of 
warming and illuminating, it would blind and burn us. 
So that the air may be confidered as having fomewhat 
of the fame effeCt, with refpeCt to the rays of light 
upon us, that the water in a balneum marine has. 
Mem. de l’Acad. ann. 1713. 
Omitting to enter into a particular difcuffion about 
the matter of the Sun, and whether it be fire, to us 
it appears very extraordinary, that the Sun, after a 
continual emiffion of the corpufcles of fire upwards of 
5 000 years, fhould not be yet exhaufted. 
Whilft the Sun is above the horizon, he impels all the 
rays, before vague and fluctuating, toward a focus, 
and fuch impulfion or determination is always in right 
lines ; fo that all our light, heat, and colour, is the 
effeCt of a reCtilinear motion. 
Suppofe, for inftance, a fire in a dark place, and 
a thermometer placed at a certain diftance therefrom, 
with an iron plate between them •, in this cafe, the 
thermometer will not be affeCted by fire, by reafon 
that the reCtilinear paffage of the heat is flopped. 
Nor need it be added, that under the like circumftances 
no light, colour, &c. are perceivable, fo that none 
of thefe aCt but in right lines. 
If there were no Sun, nor any body to fupply its place, 
there would be no heat, i. e. the fire would not be 
determined in right lines, fo that the Sun is the fa- 
ther of all heat, or fome other body that aCts in the 
fame manner as the Sun, for the Sun does not make 
heat, but only the difference between the heat of the 
day and the night. 
Dr. Halley obferves, That the Sun, radiating on the 
earth in the morning, has but little effeCt, but that, 
when raifed to the meridian, he aCts with all his force. 
Now this is owing to the atmofphere, which, being 
replete with an infinite number of corpufcles, reflects 
more of the Sun’s rays to the earth, when they fall 
perpendicularly, than would otherwife arrive there ; 
for whereas falling obliquely, they would be reflected, 
and thus be thrown off, and difperfed into other parts, 
now that their incidence is perpendicular, they will 
pals direCtly through. 
And 
