Evening journal., 1897-09-08

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SEASONS OF THE YEAR DEPEND
ON 5THIs-THE EARTH's ATMos.
PIERE NOT AFFECTED BY THE
PLANETS SATURN AND his
RINGS.
In the course OF the month of Sep
tember the phases of the moon will be
as follows: First quarter on the 3rd, |
full on the 10th, last quarter on the
18th and the new on the 26th On the
first at 5 p. IN. and on the 2sth at Z p.
m she was in perigee, and on the 18th
at 1p IN. will be in apogee.
On the 1st Of September the sun was
8 degrees 6 minutes north of the equa-
tor, and will reach 1t about 2 O'Clock p.
IA. on the 22nd. On the last of the
month It will be 3 degrees south of the
equator, thus sweeping in course of the
month Through an arc Of a little more
than, IL degrees of declination, which
is but little less than half of the whole
extent OF its course either north or
south.
The reason why the sun cannot get
higher than % degrees q minutes above
theequatorlies in the fact of the ecliptic
cutting the equator under that angle,
which is called the Obliquity of the
ecliptic. Upon this obliquity the sea-
sons Of the year depend A change in
the obliquity of the ecliptic would pro-
duce a corresponding change in
the seasons, and 1t is, there
fore quite pertinent question
whether this. important angle which
the plane OF the equator makes with
that OF sthe ecliptic is subject to any
changes. .
The ancienks labored under the dis
advantage OF making their measure
ments OF latitude, obliquity length of
the year, etc, with a very crude instru-
ment, the gnomon, which must be con-
sidered rhe simplest of all astronomical
instruments. In fact, the gnomon is
nothing more than pole. or a columnof
known height. erected on a perfectly
horizontal plane. BY measuring the
length of the shadow at neon alt def
mite times OF the year they succeeded
in arriving at tolerably correct results
In this way they determined The maxi
mum height of the sun in declinatiOn,
which is, as said before. the oblquity
CT the ecliptic. This obliquity is at
present "a minutes less than II was
1000 years ago, and it decreases about
half second each year. This con-
stant decrease will continue for about
$4,000 years. after which period it will
increase again. The minimum obliq-
uity will be % degrees Is minutes
while at present 1t is 23 degrees q min
rtes. mIla
1.-THE effect OF this diminution in the
obliquity of the ecliptic will be a slight
decrease in the Temperature in the
temperate and frigid zones, and an in
crease in that OF the tOrrid. This
change in the obliquity, like that in
the eccentricity of The earth's orbit and
the revolution OF the line OF apsides, /:
taueed by the action which the planets
exert upon the earth. We here reiter
ate that the slight changes in th'
above quantities are the only ones ths
planets exert upon the earth, and the
assertion we so often meet with of theil
exercising an influence upon our a'tmOs.
phere and the condition of the weather
is absurd and savOrs of gross ignor
ance. Atmospheric disturbances arr
due to causes that have absolutel!
nothing to do with the planets and tn
phases OF the moon. OF course, all tn
planets by virtue of the mutual attrac
tlon that prevails among them, produc
certain disturbing effects called pertur
bations. but these effects manifes
themselves by certain changes in wha
is called the elements Of the planet, bu
in nowise by the rise and fall of tn
temperature or the currents of the air
The planet Mercury will enter tn
constellation Leo in the early porto
of the month and remain in the sam
until its termination. SO will tn
planet Venus after lingering for a bri'
time in Cancer. 1t rises between an
O'Clock a. m. and consequently wi
shine as a morning star. The plane
Mars is in Virgo and Jupiter in Lee
Saturn may still be seen until nearl
IL o'clock in the evening in the bounC
airy line OF Scorpio and Libra. both
which consultations are bending t.
ward the western horizon. The planl
tary aspect Of the heavens during I'll
month of September is therefore not
favorable this year as it will be
other times.
io The next planet in distance and sii
after Jupiter is Saturn. BY the ancien
Il was considered the remotest of a
the planets. Its mean distance from Il
sr sun is about9i6 times sthedistanceo Of n
earth from the sun, or, in technic
language, 91k astronomical units. |
mean diameter is about 9 times Il
earths. which makes its volume s.
times THE earth's. Saturn performs
revolution about the sun in the loI
-,rperiod of 29is years, which causes i
slow motion among the constellation
of the zodiac. It's synodic period. hol
ever, is but 37S days One of the V
rious peculiarities of the great planet
its small density, being hut one-eigih
r, that of the earth, and therefor
its mass is only 80 times tn
of the earth OF all the plane
Saturn is the least dense. Tt turns
its axis in very nearly ten hours.
that a point on its equator revolves
times as fast as point on the equat
of the earth.
Dhere is. however. one popularity I
tashed to the planet which renders
the most magnificent and unique of
celestial objects known. Jupiter, wi
its four large satellites and the late
discovered small one certainly pl
d, sents a fine spectacle. but what can {