A S T R O N O M Y. 
Plate V. exhibited a view of them, as they really are, in 
quantity of matter or dimenfions, compared with one ano¬ 
ther; from a bare infpef'tion or which the imagination 
will readily form a correft idea of the fuperior mats of the 
jnore diftant planets, and of tlie inferior fize of thofe which 
revolve nearer the'Sun. Each planet is didinguifhed by 
its proper character, from Saturn to Meixury. The Geor¬ 
gian planet, in this arrangement, is placed under Jupiter, 
as being inferior to him in fize. 
With refpeCd to the apparent fize or magnitude of the 
Sun, as it would comparatively- appear to the eye of a 
fpedator placed on tire different planets, we have, at Jig. 4, 
in the fame Plate, illuftrated this phenomenon. If feen 
from Mercury, the Sun would appear as large as at a. 
From Venus, of the fize as at b. From the Earth, as at 
f- From Mars, of the fize at d. From Jupiter, as at e. 
From Saturn, as fmall as at f\ and from the Georgian 
planet dill fmaller, as at g. 
Of ECLIPSES. 
Thofe phenomena termed edipfes , were in former ages 
Beheld with terror and amazement, and looked upon as 
prodigies that portended calamity and mifery to mankind. 
Thefe fears, and the erroneous opinions which produced 
them, had their fource in the hieroglyphical language of 
the fird inhabitants of the Earth. The word eclipfe is 
derived from the Greek, and dignifies dereliction, a faint¬ 
ing away, or fwooning. Now as the Moon falls into the 
fhadow of the Earth, and is deprived of the Sun’s enli¬ 
vening rays, at the time of her greated brightnefs, and 
even appears pale and languid before her obfcuration, Lu¬ 
nar eclipfes were called Luna labores, the druggies or la¬ 
bours of the Moon. To relieve her from thefe imagined 
didrefies, fuperftition adopted methods equally ridiculous 
andabfurd. Plutarch alfures us, that at Rome it was not 
allowed to talk publicly of any natural caufes of eclipfes; 
the popular opinion running fo drongly in favour of their 
fupernatural production, at leaft thole of the Moon ; for, 
as to thofe of the Sun, they had feme idea that they were 
caufed by the interposition of the Moon between us and 
the Sun ; but were at a lofs for a body to interpofe be¬ 
tween us and the Moon, which they thought mud be the 
way if the eclipfes of the Moon were produced by natu¬ 
ral caufes. They therefore made a great noife with brazen 
indruments, and fet up loud fliouts, during eclipfes of the 
Moon; thinking by that means tp eafe her in labour : 
whence Juvenal, fpeakingof a talkative woman, fays, Una 
laboranti potnit fuccurrerc Luna. Others attributed the 
eclipfe of the Moon to the arts of magicians, who, by their 
inchantments, plucked her out of heaven, and made her 
Ikim over the grafs. 
The fuperditious notions entertained of eclipfes, were 
of confiderable advantage to Chridopher Columbus, the 
difcoverer of America, who being driven on the illand of 
Jhmaica in the year 1493, and didreded for want of pro- 
vifions, was refilled relief by the natives ; but having 
threatened them with a plague, and foretelling an eclipfe 
as a token of it, which happened according to his predic¬ 
tion, the barbarians were fo terrified, that they drove who 1 
fliould be the fird in bringing him fupplies, throwing them 
at his feet, and imploring forgivenefs. 
The natives of Mexico keep fad during eclipfes ; and 
particularly their women, who beat and abul'e themfelves, 
drawing blood from their arms, &c. imagining the Moon 
has been wounded by the Sun in feme quarrel between 
them. The Cliinefe fancy that eclipfes are occalioned by 
great dragons, who are ready to devour the Sun and Moon ; 
and therefore, when they perceive an eclipfe, they rattle 
drums and brafs kettles, till they think the monder, ter¬ 
rified by the noife, lets go his prey. Among other nations, 
when the Moon, by palling between us and the Sun, de¬ 
prived the Earth of its light, the Sun was thought to turn 
away his face, as if in abhorrence of the crimes of man¬ 
kind, and to threaten everlading night and definition to 
the world. But thanks to the advancement of fcience, 
£ 
which, while it has delivered us From the idle Fears and 
apprehenfions of the ancients, leaves us in podeffion of 
their reprefentative knowledge, enables 11s to explain the 
appearances on which it was founded, and points out the 
perverfion and abufe of it. 
A"ny opaque body, that is expofed to the light of the 
Sun, will cad a fhadow behind it. This fhadow is a fpace 
deprived of light, into whicli if another body comes, it 
cannot be feen for want of light; the body thus falling 
within the dark fiiadow, it is laid to be cclipfed. The Earth 
and Moon being opaque bodies, and deriving their light 
from the Sun, do each of them cad a fhadow behind, or 
towards the hemifphere oppofed to the Sun. Now when 
either the Moon or the Earth pafifes through the other’s 
fhadow, it is thereby deprived of illumination from the 
Sun, and becomes invilible to a fpedtator on the body 
from whence the fhadow comes ; and fucli fpedtator will 
obferve an eclipfe of the body which is paffing through 
the fiiadow ; while a fpedtator on the body which pafleS- 
through the fhadow^ will obferve an eclipfe of the Sun,- 
being deprived of Ins light. Hence there mud be three 
bodies concerned in an eclipfe ; 1. the luminous body; 
2. the opaque body that cads the fiiadow ; and, 3. the 
body involved in the fiiadow. 
Of Eclipses of the Moon. 
As the Earth is an opaque body, enlightened by the 
Sun, it will cad a-fiiadow towards thofe parts that are op- 
polite to the Sun, and the axis of'this fiiadow will always 
be in the plane of the ecliptic, becaufe both the Sun and 
the Earth are always there. The Sun and the Earth are. 
both' fpherical bodies; if they were therefore of an equal 
fize, the fiiadow of the Earth would be cylindrical, as in 
Jig. 1, below ; and would continue of the fame breadth 
at all didances from the Earth, and would confequently- 
extend to an infinite didance, fo that Mars, Jupiter, Sa¬ 
turn, or the Georgian, might be edipfed by it; but, as the 
planets are never edipfed by the Earth, this is not the 
diape of the fhadow, and confequently the Earth is not 
equal in fize to the Sun. If the Sun were lefis than the 
Earth, as in Jig. 2, the fiiadow would be wider the far¬ 
ther it was from the Earth, and would therefore reach to 
the orbits of Jupiter, Saturn, and the Georgian, ami’ 
eclipfe any of thefe planets when the Earth came between 
the Sun and them ; but the Earth never eclipfes them, 
therefore this is not the diape of its fiiadow, and confe¬ 
quently the Sun is not lefs than the Earth. Therefore, 
as the Earth is neither larger nor equal to the Sun, we 
may fairly conclude that it is lefs ; and that the fiiadow of 
the Earth is a cone, which ends in a point at fome didance 
from the Earth, as in fig. 3. 
The axis of the Earth’s fiiadow falls always upon that 
point of the ecliptic that is oppofite to the Sun’s geocen¬ 
tric place ; thus if the Sun be in the fiffi point of Aries, . 
the • 
