The evening Argus. [volume] (Rock Island, Ill.) 1861-1871, 1870-01-17
THE ECLIPsE-THE WEATHER, EXPLyNA-

TI0N, ETC, ETC.
Yesterday and until late hour last night,
the weather was decidedly spring like, and
the thermometer this morning indicated the
coolest weather of the season-60 above re
70. 4 sudden change said everybody. but
not most unaccountable, as our astronomers
teli us that this change occurred at the time
of this MORNINGS eclipse Of the moon, or
what is the same thing, just before. We
regret that the friendly plsnet-Miss Luna
who lights Us when old Sol gives US the
cold shoulder, should favor Us with such 4
sudden change of atmos phere just because
of a little eclipse. For the information OF
those who were not up in time, or for other
reasons, did not observe this celestial pheno.
mena, We will state that it was total
eclipse, the penumb ral phase being partly
visible through the United States The par
tisl phase was visible through the western
states, and the total phase partly visible in
Colorado, Utah, etc, and wholly visible in
the Pacific states.
These occurrences are 50 frequent, that but
but little interest is taken in them BY the
majority of people, but as we number among
our readers many scientific men as well
as large number OF our cit.
lzens who are patrons and
able supporters of our public school system
and have children in school who are inter
ested in such subjects, We give for them the
following more complete notes on the a.
fair:
1t IS well known that lunar eclipse, as
1t is called, proceeds from such conunc-
ton OF the sun, earth, and moon SIS to bring
the earth directly between the other two.
Observation as well as calcu lation mas shown
that IL a year there cannot De more than
seven or less than two eclIpses, the ratio OF
these OF the sun 20 these OF the moon being
FIVE to two. When conjunction takes place
within IS degrees 2J minutes on either side
of the moon 5 node Tor, IN other words, one
of the two positions OF the moon, when her
centre is at the same time n the plane of the
eclIPtic and IN that Of her own orbit com
pretending an arc of 30 degrees so minutes
longitude, a solar eclipse is inevitable. Dur
ing q synodic revolution of the moon, the
suns mean motion il longitude is 20 degrees
6,,minutes, and IN this time the moons nodes
move backward degree 81 minutes Hence
the sun s motion with reference to the moon $
nodes III one lunation Is 80 degrees 81 min.
utes, which is less than 30 degrees so min,
utes. One solar eclipse must occur there
near each node Of the moons orbit But It
IS possible that two solar eclipses NAV occur
near each node and also one lunar eclipse.
This is sure TO happen, if r position takes
place near the moon s node, and the moon
will Their be centrally eclipsed. Since he
sun S motion with reference 10 the node
during half lunation, is only IL degrees
3 minutes, it is evident that both ct the
previous and the following new moons the
sun may be within the ecliptic limits of the
node, and therefore be ecGpsed at each oe
the new moons. The sun will be near the
other node of the orbit at fall moon, which
occurs in less than half synodc revolution
of the sun from the last.
In consequence large lunar eclipse must
occur, and there might be an eclipse of the
sun, both st the previous and following new
moons. At the new moon, which takes
place FIVE and one half lunations from this
latter full moon, the sun will be near the
node again and must be eelipsed. Thus,
within II months there could be two eclipses
of the moon and FIVE of the sun.
Any of our city teachers can place q
diagram before their scholars, showing the
relative position Of the three heavenly bodies,
which will make this perfectly clear, as well
as make an interesting and instructive Of
ternoon exercise for their schools.