Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1898-10-06
THE SKIES DURING OCTOBER
Suns Twofold Motion in Right
AsCe nsion and Decline.
THE POSITION OF THE PLANETS
Venus lie In Close Proximity to
AntareS.
Baltimore Sun.

During the month OF October the
moon will be in her last quarter on the
7th, new on the 18th, in first quarter
on the 22d and full on the 10Th. She
will be most remote from the earth on
the 7th, at 11.54 a. MI, and nearest to
1t on the 18th, at s. "a. The sun was
degrees Is minutes south of the
equator on, the LIST of the month, and
during it swept through an arc Of IL
which. is little less than half of the
total decination it can attain. The
amount of its eastern motion among
the stars, that is, ia right ascension,
will be 20 degrees minutes % seconds.
1t is matter of great Importance to
understand clearly this twofold motion
of the sun arising from its direct mo-
tion in great circle that cuts the
equator at an oblique angle. In con-
sequence of this obliquity it performs
its north and south motion in declina-
ton, on which the seasons depend, and
q motion along the equator, or in right
ascension, on which its position among
the consultations depend. Even were
Its direct motion in the ecliptic uni
form one, its motion, both in declina-
tiop and right ascension, could not be
uniform on account of the obliquity of
the ecliptic, and for this reason it does
not travel every month through equal
arcs, either in regard to declination or
to right ascension. Its motion in de-
clination is quickest at the equinoxes
and slowest at the solstices, whereas the
reverse takes place as to the motion in
right ascension, being slowest at the
equinoxes and fastest ut the solstices.
The reader will readily see the reason
for this, since the angle which the cir
conference of the ecliptic makes with
that of the equator, or, in other words,
the obliqnity of the ecliptic, is greater
of the ecliptic and that of parallel of
latitude. Consequently, for equal in
crements on the arc of the ecliptic the
right ascension must increase and the
declination decrease from the equinoxes
to the solstices.
The planet Mercury will be in the
three consultations, Leo, Virgo and
Libra. When Mercury is at his greatest
elongation, that is, as far east or west
of the sun as it is possible for him to
be, at which time he will rise about an
hour and half before sunrise and set
after sunset, it is possible to catch a
glimpse of him with the naked eye. Dur
ing the twilight-and Mercury can be
seen only during twilight--only the
brighter planets and the first magni-
tude stars can be seen. If, then, a
bright star should be noticed, which is
neither another planet nor a fixed star,
it is quite certain that it is Mercury.
The celebrated astronomer, Copernicus,
to whom we owe the establishment of
the solar system as it is now accepted,
confessed that he had never beheld
Mercury. He labored, however, under
the difficulty of observing in higher
latitude, where the duration CT twi-
light is greater.
Venus will be in scorpio during the
whole extent of the month, and on the
10Th will be only IL degrees from An.
tares, first magnitude Star and the
brightest member of that constellation,
near which it will remain during the
remainder of the month. The brill
liancy of Venus is 50 striking as to
render it almost impossible to mistake
her for any other object in the heavens.
Her close proximity to the red and
conspicuous first magnitude star An,
tares will make these two objects ar
exceedingly attractive spectacle which
no one, that is at all interested il
celestial objects, should fail to observe
Their distance from each other on the
date mentioned and for few nights
afterward will be less than one4thir6
the distance of the two Pointers in the
Great Bear, and about equal to that O
one of the outer stars in the Belt o
Orion from the middle one. A clos,
conjunction of bright planet will
another planet or first magnitude sta
is always most interesting sight thai
cannot but engage the attention of an,
one for whom the star dotted sky is al
object of beauty and admiration. o.
the 9th of the month Venus will as
sumo her greatest brightness, bein,
then about 40 degrees from the sun
The planet Mars will be in Gemini ant
toward the end of the month on tn
boundary line Of that constellation an,
Pisces. Between II o'clock and mid
night it may be seen above the easter
horizon, shining with the brightness
of the medium first magnitude star
Jupiter is still in Virgo. The grea
planet will shine as an evening sta
until nearly the middle of the month
though, setting early, it will general
escape observation and set before tn
last glimmer of the evening twiligh
has vanished from the sky Later 0
in the month Jupiter will begin to az
in the capacity of morning star an
shine as such during the remainder {
the year. Saturn fingers yet in Scol
pic. While at the beginning of th
month it will set nearly half past 8,
will disappear from view about a qua
ter Of toward the end.
More than once we have had occasio
to refer to that peculiar irradiation
the sky before sunrise and after suns,
which appropriately has been calle
twilight. The reader that has travele
in mountainous regions cannot ha,
failed to notice that, after the sun h;
actually set in a plain, it still illumint
the tops of the mountains. The 81
before rising and after setting illumin
the clouds and upper strata of the a
mosphere, and,these again reflect ligl
to the earth below them. The phen
menon of twilight, therefore, is cause
by the atmosphere, without which
would not be possible and night wou
close in instantly after sunset. 1t h
been observed, though mathematic
precision is ia this case out of Il
question, since the exact limit of Il
atmosphere has not, and perhaps ca
not, be determined with sufficient a
curacy, that the last CLEAN of twilig
will cease when the sun is IS degre
below the horizon. AT the equator Il
circle of the diurnal motion of the s,
land the stars) cuts the horizon DC
pendicularly, and consequently the
the duration of twilight is the shortt
possible, viz; l hour 12 minutes. {
parallel of latitude the circle Of dit
nal motion cuts the horizon obliquel
and as the sun must necessarily Dc
over more than 18 degrees to move