Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1893-02-02

to lord 1t over the oVenlng planets. N Ho
will then be in conjunction with the sun;
and when he reappears, We shall see hiin
shining in the east, just little before sun
rise. One of the most interesting features
OF Jupiter il the motions of its satellites and
the various phases through which they pc
riodlcally pass. The eclipseS OF these
satellites bad been observed for many
wears. and the times OF their occurrence
had been recorded. At length 1t was per-
ceiyei that certain order reigned among
the eclipses Of the satellites, as among all
other astronomical phenomena, ana III oe-
came possible TO predict the time at whicn
these eclipses would take place. when IL
came. however, TO naming the actual
minute at which the event would take
place the predictions were not always sue
cessful. These discrepancies demanded al
tentiou. and after time resulted IN most
interesting discoveries.
TIE ECLIPSE.
II was noticed that when the earth was
near TO Jupiter the eclipse generally oc-
Cured before the predicted time, while
when the earth happened TO be at the SIDE
of its orbit away from Jupiter the eclipse
occurred after the predicted time. When
the satellite enters the shadow lts llgnt
gradually decreases until II disappears. II
Is Lut lt-L IhN VI Az III 'ipiAA Wv
satellite that gives the time OF the eclipse,
but that raw of light has to travel from the
satellite TO the.earth and enter our telescope
before we can note the occurrence.
Ii used TO be thought that light
travelled ,nstantaneously, so that the mo-
ment the eclipse took place was assumed
TO be the instant when the eclipse was
seen in the telescope. This was found to
be incorrect. and it was seen that ilght re-
uulred time 20 travel. When the earth
was near Jupiter the light had only
short journey, the impression ol
the eclipse arrived quickly, aud the
event happened sooner than the calcu-
lations indicated. When the earth occu-
pied position far from the planet the
light had q longer journey and took moro
than the average time, so that the eclipse
was later than the prediction.
This simple explanation removed tue
difficulty attending the predictions OF the
eclpses. The discovery had, however, D
significance far more momentous. for we
learned from It that light had a measura-
bic velocity, which amounts 10 lSO'OOU
miles per second.
One of the most celebrated methods OF
measuring the distance of the sun Is de-
rived from combination of experiment,
on the velocity of light with astronomIcaI
measurements. The dimensions Of the
solar system are SO considerable that q
sunbeam requires an appreclable interval
of time to span the abyss which separates
the earth from the gun. Eight minutes 1;
approximately the duration or the journey
so that at any moment we see the sun az II
would have appeared eight minutes earlier
10 an observer IN It's immediate nelgnbor
hood. We can determine this period OF
time from the eclipsss OF Jupiters satel'
lltes.
MORNING STAR.
Venus has still three months to reign a'
queen of the early morning sky, although
some little time before the end of thai
term the dawn will have so dimmed be-
brilliant light that we shall no longer be
able to find her with unalded vision
Then. too, the beautiful planet Is with
drawing from us and becoming somewhat
smaller meanwhile. She Is still, however
far enough away from the sun TO maintain
her identity, and a. she rises above tn,
sea horizon we can readily imagine Will
the ancIents that she sprang from the foam
of the ocean and is still the happy pos
SCISSOR of the girdle OF wonderful em
brOldery which cOntalns the power OF IN
spring our love and admiration.
Saturn's mellow light is again one of th'
attractions Of the heavenly drama, and VI
find this son of Terra and Uranus amonl
the morning stars about SIX hours in al
vance OF Venus IN the constellation of tn
Virgin. He Is moving along at merr'
rate toward his position IN opposition Wit
the sun, where we shall see him tw
months from to-day at his largest and il
the most favorable position for observa
ton. He will then rise as the sun SINKS Z
rest and will be IN plain sight Throughout
the night, veritable " god who Is satiste
| with his own comprehensive powers" nc
cording TO the ancient manner OF expire
sion.
Uranus reaches the position of quadra
| ture. which shows that the planet IS iu'
| 30 degrees away from the sun. and rs ther
| Is conjunction with the moon lust after th
| last quarteriug, we can readily see that th
planet IS 10 the westward of the sun an
| Is one af the morning stars. BY this tim
We are probably fully convinced of Its be
ing impossible to see Uranus without art
| ficIal and. but having produced so fine
son as Saturn we are fully justified III bt
| leYing that the parent Is worthy ane tina
We are being deprived Of great deal VI ue
| having hun near enough for US - see.
CLOSING EyEETs.
Neptune closes the months events b
| being IN Quadrature with the sun on Oh
! 2Gth. Three days before ho was III con
| junction with the moon at first quarter, 3
we see that he IS on the side of the sun OF
posite Uranus and almost lS0 degrees trol
that planet.
| Mercury Is now lost in the suns raw
and Is in superior conjunction with III.
luminary on the 10th, tho day of ne'
! moon, which shows that the three AZ
grouped IN q bunch.
Mars conjunction with the moon c
the night Of the Goth IS hls most interes
ING feature for the month. He is now g
ting so very small that il is somewhat diff
cult 10 imagine that he was once clad !
such gorgeous raiment and the observe
of all observers.