| Transcript |
- LEFT PAGE
220 Astronomy
Earth's orbit, the others are
Venus called "Superior Planets" as
their Orbits include that of
the Earth
The Primary Planets
accompanied by their Sattelites,
Annual revolve around the Sun from
Motion West to East in Various portions
of of time which are called thier
the "Periodic Revolution" or "Annual
Planets Motion"; the planes of thier
orbits all pass through the
centre of the Sun, but are inclined
more or less to that tof the Earth
crossing it in 2 points called Nodes.
Although to an
observer placed in the Sun, the
Explanation planets would appear to move in
of due order about him from West to
the East, yet, since the Earth is not
Various in the centre of the system, thier
Planetary apparent motions in the heavens,
Motions are very irregular; sometimes they
appear to move from West to East,
and then to stand Still; then
they seem to move from East to
West; and after standing some
time they again move from West
to East; and so on continually.
The motion of a planet, from
West to East is called the "Direct
Motion" or according to the order
of the Signs. The contrary motion
from East to West is called the
"Retrograde"; and when the
planets appear to stand still,
it is said to be "Stationary"
RIGHT PAGE
Astronomy 221
The situation of a Planet, in the
Situation heavens, as it would appear if seen
of from the sun, it is called its "Heliocentric
Planets Place"; and as seen from the Earth,
it's "Genocentric Place"
The Angular
distance of a planet from the Sun
Elongation is called its "Elongation"
When a
Planet is in the same part of the
heavens with the sun, those bodies
are said to be "Conjunction";
and when thier Angular distance
is 180 [degrees] in "Opposition" the same
terms are used with respect to any
other two celestial bodies
The Sun
that great fountain of light, heat
The and Vegitation, is an immese [immense]
Sun spherical body, placed near the
centre of the orbits of all the
planets; its diameter is about
882,000 English Miles, and it turns
round its axis in 25 days 8 hours.
Mercury is of
all the primary planets, the nearest
to the sun; his diameter is about
Mercury 3140 Miles, and mean distance
from that luminary, about 36 Millions
of Miles. His periodic revolution is
performed in 87 days 23 hours.
To a spectator
on the Earth, this planet Keeps so
near the Sun, that we can seldom
discern him without the aid of
telescopes; he appears sometimes
a little before sunset, and at
other times a little after
sunrise.
|
|---|
