_SUN, EARTH, AND MOON_:
PHASES AND ECLIPSES.
Consists of the Sun, the Earth, and the Moon. The object of this scene
is to display the cause of the waxing and waning of the Moon, and of
solar and lunar eclipses: for this purpose the Earth perform its annual
and diurnal motions, and projects a conical shadow opposite to the Sun
during its journey round him. The Moon borrows her light from the Sun;
and which, in reflection to the Earth, is not more than one three hundred
thousandth part so strong: and performing her rotation round the Earth,
every 29D. 12H. 44M. will sometimes shew us more and sometimes less of
the enlightened part of her body. Hence, when she is between the Earth
and the Sun, her dark side is towards us, and we lose sight of her, and
call this part of her period the CHANGE; but as she revolves round the
Earth from West to East (the same way the Earth turns on its axis) in a
few days we see her above the Sun in the West, and seeing a small part of
her enlightened face, call the appearance the Horned, or NEW Moon: (for
her dark side, receiving no reflection of light from any neighbouring
body, cannot be seen except in very clear weather). As she proceeds on
her monthly journey, when the Sun sets in the West, we see her near our
meridian, and then she appears an HALF Moon, and we say she is at the
first quarter; as she approaches the FULL, more of her enlightened side
may be seen, and she assumes an OVAL or GIBBOUS appearance. At the FULL
she is opposite to the Sun, when the inhabitants of the Earth look at her
in the same direction as the rays of that luminary, and of course see
the whole of her enlightened face. In performing the other half of her
journey, she wanes; and exposing less and less of her enlighted side to
us, again disappears.
This scene receives also auxiliary illustration, before the grand scene
opens: and in maps of the Moon during its exhibition, particularly one
of five feet diameter, made from telescopes of the largest magnifying
powers, and laid down with the most minute correctness, with maps of
the appearance of the Earth as seen from the Moon, indicating from this
similarity, that they are worlds of nearly similar construction.
In the thirteen revolutions she will make while the Earth travels round
the Sun, it will evidently appear that the Earth is a Moon to her, but
appearing thirteen times as large as the Moon to us; that she does not
shine by her own light; that she has no diversity of seasons; that she
keeps the same side always turned towards the Earth, and therefore turns
on her axis every 29½ days; that her surface is mountainous[1]; and that
she shines without setting, every second fortnight, on the arctic or
antarctic parts of our globe, during winter: a very sublime and simple
provision for the otherwise long continued darkness that at opposite
seasons of the year would invelope the polar regions of the Earth.
If the Moon moved in the same plane or level with the Earth, we should
have an eclipse every full and change; but as she travels 5¾ degrees to
the North of it, and the same to the South of it, every lunation, she
only crosses the plane of the Earth’s orbit in two places, which points
of intersection (called the Moon’s NODES) though in a trackless path,
move 19¾ degrees towards the West every year, and therefore pass round
the Heavens in 18 years and 225 days; which is the golden number of our
calendar. Hence, when one of these nodes is between the Earth and the Sun
at the change, the Moon’s shadow is thrown on the Earth, and she eclipses
the Sun; and if she comes to the full when either node is opposite to the
Sun, she falls into the Earth’s shadow, and loses for a short time her
borrowed light: hence, as she mostly passes above or below the Earth’s
shadow, we have Eclipses very seldom. These phænomena are produced in the
Eidouranion as they are in nature, and perfectly evident on inspection.