1 1814
SHORT ACCOUNT
THB
SOLAR SYSTEM,
AND
OF
COMETS IN GENERAL:
TOGETHER WITH A
PARTICULAR ACCOUNT
OB THE
со М M E T
THAT WILL APPEAR IN
1789.
-శికరంగా
BY BARTHOLOMEW BURGES.
BOSTON:
BINTID AND SOLD BY B. EDES & SON,
No. 7, State-Street. -1789.

THIS Work is moſt
humbly Dedicated to the Ameri-
can Academy of Arts and Sciences
in the State of Mafſachuſetts,
and to the Philoſophical Society
of. Pennſylvania.
By their moſt obedient,
humble Servant,
Bartholomew Burges.

A SHORT ACCOUNT, &c.
HE Sun, though in reality not exactly
placed in the center of the Solar Syſtem,
it being in one of the focuſſes of the orbits of
the planets, its diſtance from the common cen-
ter is ſo ſmall in proportion to the diameters of
planets orbits, that as it makes no ſenſible dif-
ference in the degrees of heat, light, or attrac-
tion in the approaches of the planets towards
it-as too nice a diſtinction to introduce in
general accounts of the Solar Syſtem, it is ſaid
to be in the centre of the univerſe.
The Sun is a ſtupendous body of fire, 890,000
miles in diameter. By the various attractions
of the circumvolving planets, he is agitated by
a ſmall motion round the centre of gravity of
the Syſtem, and in 25 days and 6 hours, makes
a rotation round his own axis, as is evident
from the ſpots on his diſk's diſappearing, and
returning to the fame point on his diſk again,
periodically, in the above-mentioned time.
In different periods, and at different diſtances,
revolve about the Sun, the planets.
iſt. Mercury, the neareſt to the Sun, goes
round him in 87 days and 23 hours, which
makes one of his years. In his courſe round
the Sun, he moves at the rate of 109,699 miles

4
A SHORT ACCOUNT OF
an hour : his diameter is 3,000 miles ; but hav-
ing no viſible ſpots on his diſk, his diurnal ro-
tation is unknown.
2d. Venus, the next planet in order from
the Sun, is 9,330 miles in diameter. She moves
round the Sun in 224 days and 17 hours, and
is 24 days and 8 hours turning round her axis.
From whence it appears, that there is only 9
days in one of her Solar years, making her
day and night 24 days and of ours long.
Her diſtance from the Sun is 68,891,468 miles.
3d. The Earth is the next plauet above Ve-
nus in the Syſtem. She is 7,970 miles iu diam-
eter -is 95,173,046 miles from the Sun. She
turns round her axis in 24 hours, and is 365
days, 6 hours, and 49 minutes going from any
equinox or folftiee, and 365 days, 6 hours, and
9 minutes going from any fixed ftar, and re-
turning to it again-the former being the length
of a trophical year, and the latter the length of
a fydereal year. The Earth travels at the rate
of 68,243 miles an hour, in its orbit; which
motion is upwards of 140 times ſwifter than a
cannon ball. The viciffitudes of day and night
are cauſed by the Earth's rotation round its
axis, from weſt to eaſt, which makes the Sun,
and other heavenly bodies, ſeemingly nove
from eaſt to weſt ; and the angle the Earth's
axis makes with its orbit, which is 660 30%, OC-
cafions the inequality of ſeaſons, days and
nights. The Earth is illumined by the San,
and reflected light of the Moon, and planets,
and

THI SOLAR SYSTEM.
5
and fixed stars. It is an opaque round body,
but flattened a little towards the poles, which
occaſions a difference of 35 miles between its
equatorial diameter and its axis, and, ſcientifi-
cally expreffed, makes the Earth an oblate
fpheroid. By the Earth's violent motion round
its axis, there is more matter accumulated about
the equatorial parts than any where elſe, which
occaſions the flatneſs at the poles, and ſwelling
about the equator.
The ſphericity of the Earth in other reſpect
is undeniable. Its round ſhadow on the face of
the Moon in an eclipſe; the intervention of the
convex part of the Sea between the eye and a
ſhip's maſt, head, and hull, its very rotation
round its axis, and its having been ſo often cir-
cumnavigated, leaves no manner of room to
doubt of its fpericity. The mountains and val-
lies on its furface being no more in compariſon
to its bulk than the duſt on an artificial globe.
The known, and unknown parts of the Earth,
together with the Seas, contain 199,512,559
miles ; about of which fuperfices is water.
The Earth is furrounded with an atmoſphere
of air, that preſles on all parts of its fuperfices,
and
grows thinner in meaſure as it is diſtant
from its furface. This atmoſphere buoys up
the clouds and vapours, and refracting the
ſun's
rays, prevents a ſudden tranſition from
light to darkneſs, by keeping his image in
view ſome minutes longer above the horizon
than

6
OF
A
SHORT ACCOUNT
than it would be if there were no refraction,
and brings it in fight as much ſooner before it ri-
fes, at about 6 minutes every day at a mean rate.
Our luminary, the Moon, is not conſidered as
a planet ; but only a ſatellite attendant on the
Earth ; perforining her circuit round the earth
from change to change in 29 days, 12 hours
and 44 minutes ; making 13 revolutions round
the earth, wanting 8 hours and ), whilſt the
earth is performing one revolution round the
fun ; the difference between which folar year
and lunar year is called the Epact. The Moon's
diameter is 2180 miles, and her diſtance from
the earth's centre is 240,000 miles. She goes
round her orbit in 27 days, 7 hours and 43 mi-
nutes, moving at the rate of about 22,290 miles
every hour ; and turns round her axis exactly
in the time that ſhe goes round the earth,
which is the reaſon of her keeping the ſame fide
towards us, and makes her day and night taken
together, as long as our lunar month.
The Moon has no atmoſphere, as has been
repeatedly made evident by teleſcopical obſer-
vations, conſequently, no ſeas.
Thoſe dark
ſpots in the moon, once thought to be ſeas, are
now found to be only vaft deep cavities, which
reflect not the light fo ſtrongly as others. To
her the Earth ſeems to be the biggeſt body in
the univerſe : For it appears thirteen times as
big as ſhe does to us.
4th. The planet Mars is next above the earth's
orbit.

THE
7.
SOLAR SYSTEM.
He goes
orbit. His diſtance from the ſun is 145,01 4,148
miles. His diameter is 5400
miles.
round the fun in 686 of our days and 23
hours.
His motion in his orbit is 68,243 miles an hour ;
and his diurnal rotation 24 hours & 40 minutes.
Mars is of a fiery red aſpect, and by his appul-
fes to the fixed ſtars, ſeems to be encompaſs'd
with a very grofs atmoſphere. He appears
through a teleſcope ſometimes gibbous, but ne-
ver horned.
5th. Jupiter, the biggeſt of all the planets, is
conſiderably above Mars; being 495,000,coo of
miles from the Earth wanting 24 miles. His
diameter is 94,000 miles, which makes him near
I 200 times as big as the earth, notwithſtanding
which amazing magnitude, he turns round his
own axis in 9 hours and 56 minutes, and moves
in his orbit at the rate of 25,920 miles an hour.
His year contains 10,470 days. His body is
furrounded by faint ſubſtances, called Belts, ly-
ing parallel to his equator, which by the chan-
ges obſerv'd in them are thought to be clouds.
So large a body and ſo diſtant from the Sun, he
muſt receive confiderably lefs heat and light
from it than the interior planets : To compen-
fate which, he is fupplied with 4 nioons or ſa-
tellites, fome bigger and ſome leſs than our
earth, which revolve about him in the times
and at the diſtances repreſented in the angles
of the plate.
6th. Saturn, the remoteft of all the planets, is
about 908,000,000 of miles from the Sun, and,
travelling

8
A SHORT ACCOUNT OF
travelling at the rate of 22,100 miles an hour,
he performs his revolution in 29 years, 167
days, and 5 hours. His diameter is 78,000 miles.
This planet is ſurrounded by a thin broad
luminous ring, as an artificial globe is by a ho-
rizon, with 5 moons, which revolve round him
with-out. Her ring compenſates for the finall
quantity of light he receives from the Sun.
Their orbits are repreſented in the ſcheme,
together with the ring that encompaſſes Saturn.
7th. Next in order is the planet Herſchel,diſco-
vered the 13th of March, 1781, by Mr. Herſchel,
a German aſtronomer. This planet is the moſt
exterior one that has been as yet diſcovered in
the Solar Syſtem, and two fatellites already has
been obſerved to circumvolve him. He is 83
years and almoſt 33 days performing his revo-
lution round the Sun, and is, according to the
obſervations taken by Mr. Herſchel's microme-
ter, 35,511 miles in diameter, and 1805 mil-
lions of miles diſtant from the Sun, which con-
fequently makes the diameter of his orbit, which
limits as yet the planetary fyftem, 3610 millions
of miles in diameter.
BBSIDRS the Planets, there are Comets in
various, and vaſtly eccentric Orbits revolving
about the Sun, in different ſituations and peri-
ods of time. Beyond the Orbits of theComets,
at inconceivable diſtances, are the fixed Stars,
which are fo many Suns diſpenſing light and
heat to planetary worlds,revolving round them,
SIRIUS

THE SOLAR SYSTEM.
9
SIRIUS, theGreat Dog, is computed to be 2
billions and 200,000 millions of miles from us.
So that Sound would not arrive to us from thence
in 50,000 years ; and a cannon-ball would re-
quire 700,000 years, at the rate of 480 miles
an hour to reach us.
With reſpect to the Comets, various were
the conjectures concerning them.
The extreme heat, the denſe atmoſphere,
the chaotic ſtate of the Comets, have induced
ſome to believe they are ſo many hells for tor-
menting the damnd with perpetual vicillitudes
of heat and cold. See Whiſton, &c. Some
have had the vanity even to infinuate, that Co-
mets were the works of the Devil, invented by
him to oppoſe the meaſures of the Omnipotent.
OTHERS conceiving Comets to have been
created to chaſtiſe this and other worlds, have
preſumed that theſe ignited bodies in their ap-
proaches to the Sun, in imbibing his heat, ab-
forb from him amongſt others, his moſt noxious
and malign qualities, which in their reſpective
returns and revolutions, impregnating the at-
inofpheres of the planets and circumambient
elements with the earth, as it were, by
contagion, partakes of. Hence droughts, fa-
mines,plagues, leproſies & the like, and the juices
of the human body contaminated, the brain dif-
turbed, and human paſions thereby irritated ;
rapine-fuicides-parricides and wars enfue.
Some giving a greater latitude to conjecture,
have from the great eccentricity of the Comets
orbits, and the aſtoniſhing lengths they run into
empty ſpace, conceived that they pervade other
planetary regions and their reſpective Suns, and
B
girting

to
OF
A SHORT ACCOUNT
to
girting round them as they do round ours, thus
by elliptical links connect fyſtems & fyftems to-
gether. Others as vaguely have ſurmiſed, that
HE who could create, and ſet in motion, this
greatPlanetarium, could cauſe Suns to blaze and
Comets to dive from ſuch aſtoniſhing altitudes of
ſpace, to the very centre of our ſyſtem, and
afcend again, could with the ſame eaſe, cauſe
the orbit of aComet to dilate or contract ſo as to
cauſe the Comet in its travels thro' our fyftem, to
meet in its flight this,or any otherPlanet, and daſh
it to atons. I ſay, vaguely have they furiniſed
thus, it being as inconſiſtent with the laws of rea-
fon, to admit of what is incompatible with the laws
of nature, (eſtablished by the Omnipotent)
happen. Others have thought Comets to be
fiery meteors, generated in the air, and other
opinions no leſs erroneous have been conceiv.
ed concerning them : "but ſince the great in-
provenients made in aſtronomy, and all its
collateral ſciences, chronology, optics, ſtatics,&c.
they have been diſcovered to be fixed bodies, or
earths, of prodigious denſity, and of different
degrees of inagnitude, and extenſion, revolving
about the Sun in very eccentric ellipſes, and
deſcribing equal areas in equal times. They
have long tranfucid tails illuing from that fide
which is turned froin the Sun, and are of a
much greater deriſity than the earth, for ſome
of them are heated in every period to ſuch a
degree, as would vitrify, or diſſipate any ſub-
(ſtance known to us.'
Monſieur Pingre, an eminent modern author,
in his Cometographie, ou Traite des Gometes
page 117, fays, that though it is not poffible to
determine

TN SOLAR SYSTEM.
IJ
determine at preſent the number of Comets,
there are near 580 Comets of whoſe appearance,
at leaſt there is probable teſtimony, but the
periods of only three of thein being perfectly
known, I ſhall not attempt an account of any
more, as a defcription of them will be fufficient
to convey an idea of Comets in general. The
firſt of theſe Comets appeared in the years 1531,
1607, 1682, and 1758 ; its period being 75 years.
The next that appeared was in 1532, and
1661 ; its period being 129 years neareſt. “The
interval between the paſſages of this Comet by
the perihelion in 1532 and the one of 1661 is
128 years, 89 days, and 29 minues, which added
to the time of its perihelion in 1661, allowing
for 32 of the years being Biſſextile, together
with the 11 days,to reduce to theGregorian ſtyle,
brings out the expected time of the next perihe-
lion, to be April 27th, I hour 10 minutes, 1789.'
Doctor Halley, and other Aſtronomers have
diſcovered ſuch a fimiliarity between the ele-
ments of the orbits of the Comets of 1532 and
1661, that they have left no room to doubt of
their being one, and the fame Comet, then the
interval of time between the coming to the pe-
rihelion of the Comet of 1532 and 1661, as al-
ready obſerved, being 128 years, 89 days, I
hour, and 29 minutes; we may reaſonably
expect the Comet in queftion, to be viſible the
latter end of the year 1788 or the beginning of
the tyear 1789, and certainly ſome time before
the 27th of April 1789.
It will approach us from the ſouthern part
of its orbit and therefore will have conſiderable
South latitude and with South declination.
B 2
This

12
A SHORT ACCOUNT OP
This Comet's inotion is direct.
The Perihelion diſtance of this Comet from
the Sun is o, 44, 851 ; that is, in ſuch parts as
the mean diſtance of the Sun from the Earth,
contains 100,000 parts. Then to find its diſtance
in Engliſh miles ſay,--If 100,000 parts require
95,173,000 miles, (which is the diſtance of the
Earth from the Sun) how many miles will
0,44,851 parts require and you will have the
Comet's Perihelion diſtance in Engliſh miles.
The place of its aſcending Node is 2 figns,
24 degrees, and 18 minutes, that is, 24° 18' in
Gemini.
The inclination of the Plane of its orbit to
the ecliptic is 32° 36.'
Its Perihelion forwarder in its orbit than its
afcending Node, 33° 28'.
Its Perihelion oo° 50'00" in Leo 82.
The time of its Perihelion calculated for the
Meridian of London, is fitted to 10 minutes paſt
one o'clock in the afternoon the 27th of April,
1789, then there being 70 degrees difference
of Longitude between the Meridian of London
and the Meridian of Boſton, and 15 degrees of
Longitude being equal to one hour of time
and one degree of longitude equal to 4 minutes
of time, and 15 minutes of a degree equal to I
ininute of time, in 70 degrees there will be 4 hours
and 40
minutes difference of time between Lon-
don and Boſton, which added to thePeriodic time
at London, reduces it to the
H. M. S.
Meridian of Boſton, & makes
its Perihelion at Boſton, 27th
4
April, at 50 minutes paſt 5
40
o'clock in the afternoon. 5
To
I
IO
O
O
50 o P.M.

TH SOLAR SYSTEM.
13
To perfectly elucidate which, I have annexed
to this work, a Diagram, to which I have fixed
Threads, which when extended ſhow thePerihe-
lion diſtance of the Comet--fhow the angle its
orbit makes with the ecliptic, and the diſtance
the Earth will be from it at that time - to be
meaſured from theScale on the Diagram ; and for
a further ſatisfaction to the Readers, as it is
known that the Perihelion of Comets alter
every period, and their Perihelion diſtance from
the Sun likewiſe ; they muſt recollect that
the motion the Sun has round the centre of
gravity, as has been already obſerved, bring-
ing the centre ſometimes nearer the vertex of the
Comet's orbit, and removing it ſometimes far-
ther from it will conſequently alter the Perihe-
lion diſtance, and make it greater or leſs in mea-
fure as the Sun's centre happens to be removed
nigher or farther from the vertex of the Comet's
orbit, and the point of the Perihelion alter-
ing in the Heaven's ariſes from the preceſſion of
the Equinoxes, which is a more or leſs exten-
ſive angle in proportion to the Periodic Times.
All which things being premiſed, we will now re-
turn to the Comet in queſtion, which will certain-
ly be viſible in our hemiſphere on or before the
27thApril 1789, at which time it will be between
the orbits of Mercury and Venus, and ſo fuffi-
ciently diftant from the Sun as not to be
merg'd
in his rays, before his riſing or after his ſetting,
but it muſt not be inferred from this, that theCo-
met's perihelion will happen preciſely at the above
mentioned time ; we only may reſt aſſured of
the Comet's being vifible on or before that time,
but

A SHORT ACCOUNT
Of
but how much fooner cannot be perfectly af-
certained. The Comets motions being leſs-
uniform than the Planets, and by their ap-
proaches to the Planets, particularly to the
planets Jupiter and Saturn, in their deſcent to
their perihelions and aſcent upwards again to-
wards their aphelions, are liable to be accelerated
or retarded in their motions, in proportion to
their approximation to or elongation from theſe
celeſtial bodies.
The next was the Comet that appeared in 1680.
The period of this Comet being no leſs than 575
years, cannot return till the year 2225. This
Comet at its greateſt diſtance is about 11,200
millions of ntiles from the Sun, and at its
leaſt diſtance within leſs than a third part of the
Sun's femi-diameter from the Sun's ſurface.
In this ſituation in which Sir Iſaac Newton com-
puted its heat to be 200000 times hotter than red
hot iron. It flies with the amazing velocity of
880,000 miles an hour, and theSun as ſeen from
it, appears an hundred degrees in breadth, con-
ſequently 40,000 times as big as he appears to us.
It is the opinion of Philoſophers that Comets
are capable of doing great injury to the Planets.
The Author of the Hiſtory of the Heavens
introduces, amongſt his hypotheſis, the poſſibi-
lity of the Earth’s having moved uniformly on
the plane of the Equator, till the approaches of
a Cornet, wrenching it out of its original pofi-
tion 23° 30', proluced thereby the inequality of
days, nights and ſeaſons, we now experience ;
and at the ſame time, the waters being drawn
up by the attraction of the Comet, in its ap-
proaches to the Earth, to a conſiderable diſtance
without

SOLAR SYSTEM.
15
without its furface, in their ſudden fall again,
drowned its inhabitants, and diſlocated and dif-
figure its fuperfices ; and thinks it' equally
probable, that a great body of circumambient
vapour remaining aloft, originated an atniof-
phere. Hence concludes, that through the
means of Comets, a Deluge may be cauſed in
one world, and a Conflagration in another.
By the near approaches of a Comet to the
Earth, Mr. Whiſton fuppoſes, the Deluge was
occaſioned : and he ſays, the fame Comet, in
1680, paffed ſo near the Earth's orbit, that had
the Earth then been in that part of its or bit near
which the Ccniet pafled, a ſecond Deluge, or
ſomething worſe, might have happened. He
fuppoſes, however, and it is the general opinion
of modern l'hiloſophers, that Coniets may be
very falutary to the fyftem, by being inſtrumen-
tal in recruiting the expended fuel of the Sun,
and ſupplying the exhauſted moiſture of the
planets: and ſome have ſuppoſed that they anſwer
a much nobler purpoſe, by being the habitations
of rational creatures, capable of admiring the
works of the creation- which, from the eccen-
tricity and immenſe extenſion of the Cometary
orbits, they are much better ſituated for ob-
ſerving, than the inhabitants of any of the
planets of our fyftem.
I fhall finiſh this ſhort deſcription of the Solar
Syftem by a quotation from Mr. Whifton :-
" When we conſider the infinite power and
goodnefs of the Deity--the latter inclining, and
the former enabling, him to make creatures
ſuited to all ſtates & circumſtances ; that matter
exifts only for the ſake of intelligent beings; and
that,
و

16
OF
A SHORT ACCOUNT
that, wherever we find it, it is pregnant with life,
or neceffarily ſubſervient thereto; the numberleis
fpecies, the aſtoniſhing diverſity of animals in
earth, air, water, and even on other animals ;
every blade of graſs ; every tender leaf :
every natural fluid, ſwarming with life:
and every one of theſe enjoying ſuch gra-
tifications as the nature and ſtate of each re-
quires : When we reflect, moreover, that, fome
centuries ago, till experience undeceiv'd us,
a great part of the Earth was judged uninha-
bitable ---the torrid zone, by reaſon of exceſſive
heat, and the two frigid zones, becauſe of their
intolerable cold : It ſeems highly probable,
that fuch numerous and large maſſes of dura-
ble matter as theComets are, however unlike they
may be to our Earth, are not deftitute of Be.
ings capable of contemplating with wonder, and
acknowledging with gratitude, the wiſdom,
fynmetry and beauty of the Creation ; which
is more plainly to be obſerved in their exten-
five tours through the Heavens, than in our more
confined circuit. And he concludes by obferv.
ing, “that however difficult it may be, circum-
ſtanced as we are, to find out their particular
deſtination, this is an undoubted truth, that
wherever the DEITY exerts his power, he
alſo manifeſts his wiſdom and goodneſs."
22
ERRATA.
Page 4, line 27, for "ernphical” read tropical.
p., l. 18, for “ fpericity" read fphericity.-P.8. 1. 6,
aitor (rizon" iprers, and.- -1.7, for “Her'r. His.
nou
1789
9285
Barthelonen