The aegis & intelligencer. [volume] (Bel Air, Md.) 1864-1923, 1877-11-02
For tile Agis and Intelligence,
Harvest Moon.

The moon moves around the earth from
West to East, but is made to appear to
move In the sky in an opposite direction by
the revolution OF the earth upon its axis also
from West to East. The apparent motion of
the sun from East to West, rising in the East
and setting in the West, results from the
same cause. That the moon moves around
the earth from West to East is made visibly
evident on the occasion of total eclipse
of the moon, when the moon is seen to en-
ter the eartE's shadow from the East, first
dipping its eastern side into the earth's
shadow, and then passing through from
West to East, and at no other time do we
ever sec the true motion of the moon. It's
eastward motion may also be known by its
change of place among the stars from even
ing to evening. If the earth had no mo-
ton on its axis, the moon would be seen
to rise in the West, attain its greatest alti
tude in between seven and eight DAYS, then
gradually decline to the East, and after the
same interval set in the East, so remaining
above the horizon between fourteen and
fifteen days, and beneath as long.
Let us now fix in the imagination the
moon moving off into space directly to the
East in its great orbit about the earth, a
quarter Of million miles away. AS the
earth turns on its axis over to the East. it
brings the retreating moon above our east
ern horizon; it brings it over our heads,
it brings it down to the horizon in the
West. The western hills hide it: but OBJ
serve, the moon is still and always travel
ing on to the East, and in days travel it
advances so far that it requires the earth
to turn on some fifty minutes longer each
succeeding evening in order to bring the
moon above the horizon, that is, the moon
rises on an average fifty minutes later even
ing by evening. This interval varies in
this latitude from 25 minutes in September
to one hour and sixteen minutes in March.
the shortest interval occurring at the au
tumnal equinox, and the longest at the
vernal. That is, suppose the moon to rise
full on the goth of September at 6 o'clock
in the evening. The next evening it will
rise at 6.25, and the next evening a few
minutes before o'clock, and so on with
an interval increasing four to five minutes.
while in March if it rises at o'clock, on
the next evening it will not rise till about
Is minutes after o'clock, or after an inter
val of II hours and so on.
NON, Illlo lOI oCNCldl evenings puIlVllS-
ing full moon in September and October is
the Harvest and Hunters Moon, so called,
indicating the late harvests of England
and Northern Europe, and the light to the
late-rcturning deer hunter in October, the
season of commencing this sport. Now,
the cause of this longer and shorter inter.
val / will endeavor to explain; but the sub
,ject is little intricate without globes or
drawings, and will require the studious at
tention of the reader, with some little after
thought With a celestial globe it may be
clearly shown even to those who have little
use in these things.
Were one located at the pole, his horizon
would be a circle Coincident with the par
allels of latitude, and when the sun or
moon was once above his horizon, it would
revolve parallel with his horizon, showing
itself, for instance, between the hills, then
setting again along the varying line-now
obscured by mountains, now appearing
where valley lets down the horizon line
ever rising higher and higher, and in the
case of the sun, till it had attained an alti-
tude of 235 degrees, and then gradually
declining, and finally, after six months un,
interrupted day, the sun would disappear
below his horizon not to rise again for six
months. We are located in latitude 391o,
our horizon extends obliquely upon the
side of the sphere. To help the imagina-
ton. let the reader suppose himself to cut
out small circle of paper, to pierce its
centre with pin and fix it to the 30th
parallel of an artificial globe, so that its
circumference shall extend downward
nearly to the equator This circle of white
paper shall represent our horizon-our
sensible horizon. Now at the autumnal, as
at the vernal equinox, the earth leans side
wise to the sun, so as to have the sun ex-
actly over her equator, while the plane of
her equator dips 23b degrees on one side
below the plane that passes through the
centres of the earth and sun, called the
elliptic, and rises 23a degrees above it on
the other side. Now, as the earth rolls on
in its orbit in the direction towards which
it leans, (being now about to make winter
in the northern hemsphere,) observe that it
brings portion of the lower circumference
of our circle nearly parallel with the eclp-
tic, or the plane in which the sun and
moon move, Qor would say nothing now
of the II degrees which the moon may
be higher or lower than the SUM- A por-
ton of the lower circumference of our
horizon is brought down nearly parallel
with the path of the moon, and hence in
days travel in her orbit she does not gain
so far upon the daily revolution of the
earth, and SO is brought up above the hor-
lion after an interval of only 20 minutes