The Somerset reporter., 1893-12-11
Harvest and Hunters Moons
Popular Science Ne,rs.

The time of moonrise on any day is on
the average about 81 minutes later than
it was on the preceding day. This re-
Ia, dation is, however, by no means con-
slant In amount, being at times very
much less than the average and at times
very much greater. A very marked
diminution in the time Of retardation
occurs about the time of the full moon
which falls in September. This moon is
called the harvest moon. The same
phenomenon in less degree occurs at
the time of the next following full moon.
which is known as the hunters moon.
The time of retardation during the har-
vest moon is less than half an hour in
our ATTITUDES, instead of its average
value of nearly an hour, and for several
successive nights the moon seems to rise
al nearly the same time.
Briefly stated, the cause of the phe-
nomenon Is this: At the time of the
rising of the harvest moon the apparent
path of the moon among the stars is
much less inclined to the horizon than it
Is ut other times, and the ordinary days
motion of the moon along this path
makes an unusually small change of
position of>the moon with reference to
its distance from the horizon.
A more detailed explanation, may
make the matter little more easily I'M
derstood. In addition to the ordinary
apparent daily motion which the moon
has. in common with all other heavenly
bodies, it has another motion by which
it conn letes the circuit of the heavens
relatively to the sun once II month, and
the direction of this motion is generally
not parallel with the direction of the
diurnal motion, it being generally north
ward or southwark as well as eastward
Anyone may see this motion by an hours
watching of the relative positions of the
moon and star near it. The diurnal
motion is always On a line at right angles
to line drawn from the body to the
celestial pole, the point in the heavens
approximately indicated by the pole
star. 1t is always perfectly uniform
about the pole as a centre, and it is this
which we take as our ordinary measure
of time.
Now consider the position of the moon
and the sun ut the time of full moon
The moon rises just us the sun sets. On
the next evening at sunset the moon will
stillbe below the horizon. because it has
moved eastward among the stars rela-
lively to the sun, and it will not rise I'M
til the diurnal motion of the heavens
brings it above the horizon. If the
moons motion were uniform and always
along the line of ordinary diurnal motion
the retardation of the time of rising
would always be the same, and would,
as stated at the outset, be tifty-one min
utes per day. But at the time of harvest
moon the direction of motion of the
moon among the stars is considerably
nOrthward as well as eastward and mt
the time of moonrisn this line makes a
comparatively small angle with the hori-
zon, very much less than it does at other
times of full moon during the year.
Therefore, at sunset on the day after the
full, the moon having moved along
! line which is inclined to the horizon at
much smaller angle than usual, its dis
lance below the horizon will be less than
the average, and hence a smaller amount
of diurnal motion will bring it into view
that is, the retardation of time of
rising is less than it is at other times.
| This condition continues for several
DAYS