Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1899-01-31
Projection of Celestial Objects on
the Vault of the Heavens.
baltimore SUM &,


From merely looking II suc1 an object 1t
IS impossible 10 form any correct esti-
mate Of its distance from us, so that
the comparatively near moon looks as
distant from us as the remotest planet
or any fixed star. This explains the APP
parent motion OF the sum- moon, ami
planets. The sun moves in a great circle
that Is inclined 10 the equator at an
angle OF p degrees and q minutes, and IN
consequence of this angle we see 1t move
I'm twO-fOld manner. eastward among the
stars and north and southwark. the for
ner being its motion in right ascension
and the latter i'm declinatOn, upon when
the seasons depend. Surprising an object
To be thrown oblquely into the air. say
toward the west 1t will. as long as IT is
rising. continuously recede from the
ground and continuously approach any
object lying due west Of II. Seen from
great distance the body will appear rs
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 20
diacal consultations from Aries 10 Pisces
and from the tropic of Cancer to that of
Capricorn. Surprising the suns. motion
I'm the ecliptic were uniform, neither that
in right ascension nor In declinatOn could
be so. as even 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 a COM
plete revolution on its axis. and this in
terval IS. according 10 observations. in
variable. This day is the sidcreal. which,
for exclusively astronomical purposes
would serve as the best unit for mea-
surfing time. However we cannot but
take the sun into account. and when the
earth has made one rotation on its axis
the sun I'm the mean time has moved
something less than a degree eastward,
so that 4 solar day, which Is the interval
between two successive returns Of the
sun 10 the same meridian. must needs be
different from and longer than sidereal
day. This difference is most simply eN-
pressed by saying that 3G5 Ii sidereal
days are equal 10 365 IA solar days In
connection with this. we mention a Curl
Gus error that we sometimes notice. even
in textbooks Of geOgraphy-viz that the
earth rOtates 36j II times during a year.
From what has just been said the read
er will clearly perceive the incOrrectness
%, this statement The year having 1856 ii
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 over
head. Measuring the apparent diameters
Of these two bodies with any sltable IN.
strument, or even looking at them
through a small tube of pasteboard. We
at once discover that We INDUCED IN an
optical illusion. on the horizon bOtn
bodies even are by the earth's radius
more distant from US than when over
head. and should. therefore, appear
smaller when on the horizon. since the
magnitude Of the visual angle subtendeu
10y the diameter is I'm the inverse ratio OF
the distance. In regard TO the remote
sun so small a distance as the earth's
radius IS an almost vanishing quantity
compared with the enormous distance OF
our great luminary. but as 10 the moon
ii becomes a perceptible factor.
THE PLANET MARS.
When during the evenings Of February
the irrldiatIOn 0f tine sky. arising rom
the evening tWiii hf has sufficiently
faded TO permit the brighter stars TO emit
then GENIAL light bright gees st.. MAJ
be seen low down in the east, which, by
ITS redness and brightness. VIII at 0nca
be recognized as the planet Mars, Of all
the visible objects i'm the heavens. with
the exception of the fiery sun itself. the
most intensely red. After a long alb.
s,nce 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 hign
up in the SKY, the two brigh; hxed stars
Castor ana PolluN-in the constellation OF
the Gemlni, Will be seen not far from Mars
III present situation. which, by his
ncry presence renders that portion OF the
heavenly vault particularly cOnspcu-
Gus, and cannot fail to engage the atten-
ton OF any one that considers II worth
his while 90 cast his eyes occasionally at
the marvellous map Of the heavens
VENUS AND JUPITER.
Venus and Jupiter are still morning
stars. the former rising alb ut o'clock
in the morning. the latter about midnight.
Venus Is IN Scorpio and Jupiter IN Virgo.
These two beautiful planets may be seen
by early risers in the morning skies shin
ing with that won lrOus lustrc that forms
ono OF their characteristic faaturas.
Saturn is still I'm Sagttarius. adding It's
brightness 10 the general appearance of
the morning sky and enhancing It's beauty.
Inferior 20 Sirius I'm brllliancy, il sufii-
ciently outshines the other fixed stars
To be recognized as planet. shining with
a steady. yellOwish light. which. though
II changes but little IN appearance from
month TO month. within period Of fifteen
years gains and loses nearly one half
Of It's brightness, according to the phases
OF its rings
THE HEAVENS IN THEIR GLORY.
The principal consultations that in our
latitude come To the meridian az about
O'Clock in the February evenings are
orion. CAMS Major. and Gemini In
ciouCless nights the sky at all times pre-
scnts fine appearance, but al no time
such a splendid one as when the constel-
latlon of Orion is high up in the heavens.
as 1t will be during this and the greater
part Of next month. Ii contains two
stars OF the first magnitude. four OF the
second, and a number of lower maeni-
tude. IL representes a giant with b-t.
sword. and a club. which he brandlshe5
in his right hand. while with his left he
holds the Hons skin. The first maeni-
tude stars are Betelgeuse and Rigel. the
former marking one Of the two shout
ders. the latter the left foot Not Tar
from Betelgegse or Alpha OriOnis. "A
bright second magnitude star marks Tho
other shoulder. which is called Gamma.
or Bellatrix. Half way between Betel-
geuse and Rigel three fine second maeni-
tude stars at a distance OF one and one
half degrees from each other indicate the
position Of the great Hunters Belt. Thes.
are called Delta or Mintaka. Epsilon or
Alnilam. and Zeta or Alniiah. These
three stars are sometimes distinguish "a
by the name Of 'the three stars" proba-
bly, because they are OF SUCH a unique APP
pearance as 10 position and equality OF
brightness. Occasionally We meet win
the u4me NJ ssThe 'Th~ea kinae si-..