The Cairo bulletin. (Cairo, Ill.) 1???-1928, 1910-05-23
ECLIPSE Of NOON
WILL BE VISIBLE IN CAIRO TO-
NIGHT FROM $40 p. M.
TILL 1890 A. Nj.
viii Be Total Lasting Six Hours
Caused BY Earth's Shadow
Second of Series of Four
This Year.

| through the earth's shadow and be
totally eclipsed, the phenomenon be-
ing visible to North and South Ameri-
| ca. the Atlantic and Pacific oceans,
and in part to Southwest Europe, the
western portions of Africa and the ex-
IRENE western portion OF Australia.
This eclipse will be the second in
| the series of four. two of the sun and
two of the moon, announced for the
present year: beginning on the even
| ing of May 20 and ending on the fol-
lowing morning, and it will afford an
Interesting exhibition well worth OBJ
serving should the sky be favorable,
| it will also be the privilege of OBJ
servers to view the imposing spec
tacle without any optical assistance
whatever for an eclipse Of the moon
may be seen just as well by the naked
/ eye, and telescope will not be neces-
sary.
The eclipse will be visible from be-
ginning to end throughout the United
States, the weather permitting, and
the moon will remain in the earth's
shadow for three hours and thirty-six
minutes. The moon will enter the
shadow at DAG p. m. and leave it at
l:22 a. m, the middle of the eclipse
occurring at l1:34 p. m. central stand
ard time, and the total phase will
continue for almost one hour. As the
moons diameter is divided into
twelve equal parts, called "digits,"
the magnitude of the eclipse will be
thirteen and two-tenths digits, so that
it will be little more than total The
eclipse beginning when the moon is
well elevated above the horizon, and
at a convenient hour in the evening,
1T will occur under the most favorable
conditions for observation, and next
to the appearance of Halley's comet,
1T will be the most popular celestial
event OF the year.
Lasts Six Hours.
When the moon is immersed in the
earth's shadow her disk will appear
dimmed as If covered with a dark
veil, and her unusual faintness at the
time of her "full' can not fail to at.
tract attention If clouds do not OBJ
scure the view, The total phase will
begin at 1900 p. IN, and end at mid
night, but the moon will not leave the
outer shadow until 2:3e a. m. the en-.
tire eclipse lasting six hours and four
minutes.
An eclipse of the moon is produced
by the moon passing into the earths
shadow, which can never occur except
at the time of "full moon," when the
moon Is in opposition and rises at sun.
set, the earth coming between the
sun and moon and casting a dark
shadow over the moons disk. The
eafth's shadow being produced by the
earth intercepting the suns light, and
as the sun is more than 100000
times larger, it will be observed that
this shadow must be conical in form.
Ii small globe or ball be held in
front of bright light, and It's shadow
be allowed to fall upon the wall or
q screen, it will be noticed that |
around the dark shadow there will |
appear fainter one. The same is
equally true in regard to the earth |
md its shadow, the dark shadow be-
ng known as the umhra, while the
lighter one Is termed penumbra.
When the moon enters the latter, or
outer, shadow, her light, produced by
'eflecting that received from the sun
$ only partially obscured, but IL at
my time the moon comes within thel
'ormer her light is nearly, IL not
lmost wholly, obscured, and total
eclipse results.
II the plane of the moons orbit CO.
NEEDED with that of the earth, there
would be a lunar eclipse each month,
nd at every full" moon But her
rbit. being inclined to the earth's
rbit. or ecliptic, at an angle of about
degrees, when the moon has reach
d her "fnll' at opposition, she
sually passes either above or below
he earth's shadow, In which condi-
ions no eclipse possibly can occur.
% produce such an event the moon
1ust be "full' at or near one of those
oints In her orbit where she crosses
he ecliptic, in moving north or south
hitch positions are known respec-
lvely as the moons ascending and
ascending node. When thus situat-
d, the earth, sun and moon are near
7 In straight line with each other,
he earth being between the other
wo, and under these conditions the
loon, at her full, must pass through
ne earths shadow and be eclipsed,
ither totally or partially.
The length OF the earth's shadow
! nearly four times the distance
rom the earth to the moon, which is
bout 100000 miles. and the moon,
hen eclipsed, passes through the
roader part of 1t, the breadth of the
nadow where the moon crosses il
eing two and two-thirds times the
readth of the moon. The duration