Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1897-12-02
THE DECENBER SKY PHASES
Sun Plays Important Part in
Measuring Time.
ITS SLOW MOTION N0RTHWARD
Tho Variable Stars Algol and
Mira.


baltimore Sun.
/ During thu month of Decemher tho
moon will pass through her phasas as
1 follows: Full on the Sth, list quarter
uG tho 18th, new on tho BID and iirst
| quarter on the i0th. At 5. % a. IN. on
| tho sth abe will ba farthest from and
| l01c y. IN. on tho 22d noarcst to tho
earth. The sun will lie on tho lst OF the
month 81 degrpna 81 minutes south of
tho enuntor, and will roach its south
ernmoBt limit on tho 2lst. 1t will then
| Rlnwly move nuIthwatd again, trAvers
ing during the remainder Of tine month
the small are of a little more than %
minutes. During the month the aun
wall he first in SCurpio anu then in
Sagittarius. Tho sun plays an all.im-
rortant part in the measurement of
time. anu for this reason, as in other
respects, astronomy cunfBrs in this re-
spect great benefit unon mankind
ClOcKH we're not used before the eighth
or ninth century Of the Christian era,
while watches arn of comparatively
recent origin. Eefore these useful in
ventinns sun diaa were resorted 10.
We're the motion Ut thu sun uniform,
these sun -dials. accurately constructed,
would do very well fur measuring time,
hut The sun moves in an elongated
curve, the eillpse, the plane of which
10 inclined to tho equator at an anglia
of 90 isgrces 81 minutes. The earth is
rot nwaya ut tho same distance from
the ain. On tho LIST of January 1t is
nearest to it, or, to use n technical OK.
preston, in perihelion, while on the lot
nf July it is farthnst away, or in
aphplion. In the former lmsitioh the
apparent motion Of tho sun is most
rapid, in the latter slowest.
Tho reader will readily understand
that the real sun in it's variable motion
presents an obstacle TO its being used
MS a time measurer. For this reason a
! so called mean sun has been chusen,
whose imaginary mntion is uniform.
Since the real sun performs a complete
circuit-that iH, an arc OF 300 degrees
in $50 days . hours IS minutes ~
seconds, the tally motion of the mean
aun 10 80 minuIes seconds. As mat
ter Of course, the mean sun will some
/ times I've ahead of, sometimes lag be-
hind tho real sun, and on four Distinct
dates OF the yoar coincide with it, viz,
ApriI 18th, June nth, September LIST
and December 2lth. On these dates a
! good sun-dial will indicate correct
| time. On all other days certain
quantity, varying, however, in value,
, must either be added to or subtracteG
from the sun -dlal time in order to OBJ
tain the correct mean time. This yari-
9 able quantity is called the equation of
3 time and is of the highest importance.
1t ia given in the nautical almanaca for
{ every day OF the year.
The planet Mercury stays during the
whole month within the boundary line
: OF Sagittarius. Venus will he in
8 Soorpio during the greater portion of
I the month, but pass into Sagittarius
i toward the end On the LIST of the
!, month she will riss about 3. 30 a. m.
= and toward the end an hour later
2 Mars is also in Sagittarius and will rise
+ nearly Z D clock 10 tho morning, so that
|. both Venus and Mars will hardly be
a visible during the December nights.
: jupiter beng in Virgo, will become
. visble soon after midnight and present
= for few hours before the dawn of day
9 fine object in the sky Saturn is still
q lingering in Scorpio, and will not rise
II before 6 O'Clock in tho morning, SO that
j, this planet, lIks Venus and Mars, will
not adoru the nocturnal skies Uranus
u and Neptune have not essentially
% changed their position since the past
IT month.
/ During the month Of December the
considerations Aries, Ctus and Perseut
will come to the meridian. Aries, oil
the Ram, ia the first constellation Of
r, the zodiac. Due east of the square oil
"a Pegasus at distance a little greater
than the sire OF that square, the OBJ.
= server will notice three stars forming a
M small triangle with very obtuse angle,
a. the characteristic star-group of Aries,
10 Tho most northern OF these three stars
10 hn hriDhaot un1 10 ralln1 lnht
i Arietis, or Hamal. The stars at thu
obtuse angle ia Beta. or Sheratan, anr
~ tho third Gamma, or Merarthim, flint
ot double star. Tho star Alma may alst
ia be found by the fact OF its forming
H. large iaoscGos triangle with Alpha ant
8sta OF the constellation Andromeda
Alpha Arietia being ms distant from
~ Beta .andromedae as the latter from
I ~ Alpha Antiromedaa.
W Two thousand years ago the constela
~ tion Aries conceded with the frat sign
~ OF the ecllptic. but in consequence o
10 the procession of the eguinoxes thl
- considerations OF the zodiac have shiftet
NJ westward, and the constellation Arie
i.t Is now in the sign Taurus and the con
US stell8tion Taurus in the sign Gemini
South of Aries lies the extensive con
a oscillation CetuH. or the Whale, occupy
We ing a space Of 30 degrees in length an,
j. 30 degrees in breadth. This head OF tn
Nd monster is marked by pentagon Of fv
- stars tho two soutbernmost of whicl
az are Alpha, or Mankar, hetween til
nj second and third magnitude, AM
lat Gamma between the third and fourtl
al magnitude Tho brightest star in th
nd constellation occupies Homewha
nj isolated position southwest OF Alpha
:" 1t is called Beta, or Deneb Ceti, an
4, is of tho second magnitude.
INT Drawing stright line from Alpha t
Beta and dividing it into three equH
ise parts the star in the first point of divi
or sion from Alpha is one Of the most re
markabe of the variable stars. II
as name is Omicron Ceti. but it is ais
On called, from it's peculiar nature. Mira
ely or the wonderful star. 1t was in fact
ted the first variable star discovered. II
Of changes OF brightness are wonusrtull
various. Being generally OF tue mint
magnitude and, therefore, invisible
rae the naked eye, it changes within
by months to the fourth magnitude, eva
nd TO the second magnitude, then hac
cd again, the whole change taking nlac
oal within 100 days. The rise in bright
l"' nesB is much quicker than the fall.
re- Midway betwean Gamma Andr,
lnedae the third one in the handle
ter and Aries we see three stars thar forl
mt a small right triangle. which is Gallo
-, Triangular mentioned among the 1
ancient consultations. Extending Il
OF hHnde Of Andromeda bright star
'nd tho second magnitude will be noticed
AL which ia thu brightest in the constell