The Ottawa free trader. [volume] (Ottawa, Ill.) 1843-1916, 1874-10-24

How ECLIPsES OCCUR.--l have said that
the sun pursues a certain definite path among
the stars, about half degree wide, which you
could see if he left any trace there; so, also,
if you could mark the position of the moon
tonight among the stars, and mark It's POSI-
ton at every hour during her whole course,
you would find that she also has pursued a
definite path among the stars, but you would
not find this path to be the same as the sun s
path 1t 1t were the same, we should have
an eclipse of the sun every time the moon
cross the sun, and an eclipse OF the moon ev-
cry time that the moon passed on the other
side of the earth from the sun. But the two
paths are inclined to each other about %
They cross each other at a point which, in
the month of October, 1874, Is very near the
sun The moons path is south, OF the suns
in nearly all that part of the heavens winch
we can see in the evening of that month"; but
it approaches the suns path, and crosses 1t
near the eastern horizon, and in most of the
Invisible half of the sphere, or that part be
low the horizon, the moons path is farther
north All this will be clear on exam
ming the star maps where the dotted
line shows the path of the moon during the
year 1874, crossing the suns path III the con
s'clalons Aries and Libra.
These two opposite points i'll which the
moons path crosses the path of the sun are
called nodes. 1t is very clear that unless the
sui Is Eear one OF the moons nodes when the
moon herself passes by, the moon will pass
above or below the sun, according as her
path is above or below that of the sun at this
point. and consequently there will be no
eclipse But if the sun happens Ia be near
the node, then the moon will necessarily pass
over his face and eclipse some portion of
him. Now, rs have Just explained, there
|arc two opposite nodes; the one set few
hours ago, and the other has Just risen Since
the sun makes the whole circuit OF the heav-
ems IN the course of year, he crosses the
moons nodes twice in that time. In 1874 he
crossed one Dodc in May, will cross the other
node in November; consequently il is Only
about these two times that any eclipse can
take place during this year.
ii the moon always followed the same path
IN the heavens, we could never have any
ccllpScs but at those two seasons. But if we
waicn the motions of the moon for several
wears in succession, we shall find tina, her
path is continually changing. At the pres
cnt time she passes seven degrees north OF
Aldebaran; Il month hence she will seem to
pass the star at almost exactly the same dis
| lance; but if you continue your observations
/ for four or five months, you will find that she
passes it perceptibly farther north, and in
/ three years you will find that she crosses 1t
/ al the distance of about ten degrees After
] that she would begin To cross farther south.
passing nearer Aldebaran at every revolution
4 for eight years, until in 1885 and 1886 she
will pass directly over it 1.-THE moons path
were painted on the heavens, you would see
that every time the moon came round TO the
same point in her path, which takes place
about every twenty-seven days, she would
cross the suns path about three of her own
! diameiers sOotr than the month before. In