Virginian-pilot. (Norfolk, Va.) 1898-1911, 1899-02-01
FEBRUARY SKIES
Celestial Objects on the Vaults of
Heaven.
nud Jupiter The Heavens tn Their
Glory The Dog Stars - other
bright Stars.

During the month OF February the
moon Will go through her phases as fol-
lows: Last quarter on the 9Th. new on
the 1lth. first quarter on the 18th and
full on the 26th. She will be nearest
the earth on the 18th and most remote
on the 18th. In course of the month
the sun will sweep through an arc OF
about 9E degrees in south declination.
being at the end of the month n little
over ! degrees from the equator When
we look at any celestial object no mat
ter whether ii is the sun or the moon.
| or planet or Il fixed star. we see IT,
as IL were, projected upon the inner
surface of an immense sphere. which
may quite appropriately be called. and
| is not lnirequently SO called, the Celes-
,ial vault. From merely looking at
such an object it is impossible TO form
| any correct distant from us as the re-
! hottest planet or any fixed star. This
| explains the apparent motion OF the
sum- moon and planets. The sun moves
Ill Il great circle that is inclined to the
equator at an angle of % degrees and
q minutes, and in consequence OF this
| angle we see ii move in two fold man.
ner. eastward among the stars and
north and southwark. the former being
IT'S motion in right ascension and tine
| ''>>NN' "a hNNililohliOll, UPON WHICH tEa
seasons depend.
surprising an object to be thrown
| otlquely into the air. say, toward the
| West. 1t Will, as long as il is rising
continuously recede from the ground
and continuously approach and object
| lying due west of it. Seen from
great distance the body will appear as
moving toward the west, and at the
same time receding from the surface OF
the earth. This two-fold motion of the
| sun accounts for his motion through
| the Zodiacal consultations from Aries
| to Pisces and from the tropc of Cancer
| to that of Capricorn. Surprising the
| suns motion in the ecliptic were uni
form. neither that In right ascension
nor in declination could be so. as even
a dull mind will readily comprehend
| and consequently neither the solar
days can be equal nor the arcs which
the sun makes every month in its
| northern and southern motion.
THE DAYS.
A day is often defined as the interval
| within which the earth performs n
complete revolution on It's axis. and
this interval is, according 10 observa-
tons. invariable. This day is the sid
| ereal, which for exclusively astrono-
| mical purposes, would serve as the
best unit for measuring time. How
| ever, we cannot but take the sun into
account and when the earth has made
1
the meantime has moved something
| less than Il degree eastward, so that a
| solar day, which is the interval be-
| tween two successive returns of the sun
| to the same meridian, must needs be
| different from and longer than n sid
ereal day. This difference is most sim
ply impressed by saying that 1864
| sidereal days are equal to 365A solar
| days. In connection with this We men
ton curious error that we some
times notice even in text books OF
| geogra ply, viz, that the earth rotates
| 365A times during n year.
From what has just been said the
reader will clearly perceive the incor-
rectness of that statement. The year
having 1864 sidereal days. the earth
must in that time perform as many
aXial rotations Another erroneous
| opinion we sometimes meet with is that
the sun and moon near the horizon are
| larger than when overhead. Measuring
the apparent diameters of these two
bodies with any suitable instrument. or
even looking at them through n small
| tube of pasteboard. we at once discover
! that we INDUCED in an optical illusion.
On the horizon both bodies even are
by the earth's radius more distant from
| us than when overhead and should
therefore. appear smaller when on the
| horizon, since the magnitude of the
visual angle subtended by the diameter
| In regard to the remote sun so small a
| distance as the carth's radius is an al
! most vanishing quantity compared with
I the enormous distance of our great
luminary. but as To the moon it be-
comes IL perccptible factor
THE PLANET MARS
When during the evenings of Febru-
airy the irradiation of the sky. arising
| from the evening twilight. has suni-
| GENTLY faded to permit the brighter
stars to emit their genial light, a bright
red star may be seen low down in
the east. which by its redness and
| brightness will al once be recognized
as the planet Mars, of all the visible
objects in the heavens. with the excep-
| ton OF the fiery sun itself, the most
| Intensely red. After a long absence
! from the evening skies this fine planet
Will act from now until the end OF
| October in the capacity of an evening
star. Northeast of Orion. which is high
! up in the sky. the two bright fixed
stars, Castor and Pollux. in the constel.
lation of the Gemini. will be seen no.:
| far from Mars in present situation
which by his fiery presence renders
that portion of the heavenly vault par
| ticularly conspicuous and cannot fan
to engage the attention OF any one that
considers il worth his while to east his
eyes occasionally a the marvellous map
of the heavens
VENUS AND JUPITER.
Venus and Jupiter are still morning
stars. the former rising about 4 o'clock
in the morning. the latter about mid
night Venus is in Scorpio and Jupiter
in Virgo. These two beautiful planets
may be seen by early rSers i'm the.
morning skies shining with tina won
drous lustre that forms one OF their
characteristic features. Saturn is ram
in SaCittarius, adding its brightness To
Of
sky and enhancing its beauty. Inferior
to Sirius in brilliancy. II sufficiently