Evening star. [volume] (Washington, D.C.) 1854-1972, 1895-09-03
Schedule Arranged for the Perform
ance Tonight.
ABOUT ECLIPSfS In GENERAL
How an Amateur Can Make Obser-
+ Nations.
THE EARTH'S SH ADOW

lows, IN standard eastern time, or tnat OF
| Washington clocks and watches:
I. Moon enters penumbraSept 3. 9:4s pm.
| II. Moon enters shadow Sept. 8, liz IN.
| III Total eclipse begins. Sept. 4, 1906 IN.
| ". Middle Of eclipse. .....Sept. 4, 1881 AIN.
| v; Total eclipse ends. .....Sept. 4. las am.
VI Moon leaves shadow. Sept. 4, 2:5i am.
VII Moon leaves penumbraSept 4, 4:06 am.
The cause and explanation Of eclipses Is
| quite simple. We have the sun. earth and
! moon moving in space, according to sim
pie and definite law. The sun alone is
| self-luminous: the earth and moon are dark,
prague bodies and hence cast shadows
away from the sun.
| Now. it is easy to see that these three
| bodies may come into straight line.
! whence an eclipse Is inevitable. When the
moon comes between the sun and earth. II
blots out a part or all of Old Soils face,
| and solar eclipse results, either partlal
or total.
If the earth is in the middle when all are
| in line. it's shadow falls upon the moon,
and We have q lunar eclipse, such as &C.
ours tonight.
The line which one may conceive as
| latter in a plane. just as the spoke of a
| hy-wheel moves about the hub.- or shaXt
| This plane, in which the earth's shadow
moves. is called the ecliptic. The lllustra a
ow is well represented by the outer END
Of the spoke, by taking the earth as a
point several inches inside the rim. on the
spoke.
The Moons Orbit.
Now the moon moves In a similar, but
| much smaller orbit, around the earth; and
| II the path Of our satellite happened to oc-
| cupy the same plane as the eclipttc, then
| there would be two eclipses each month;
| for twice would the three bodies come in
line in each revolution of the moon. This
would give solar eclipse at new moon,
and a lunar eclipse when the moon was
| full
Nature has obviated such a monotonous
| order of things by "tilting" the orbit of
our satellite at an angle OF about nve
degrees to the ecliptic. The two points
| where her orbit cuts the earth's plane are
called the nodes; since the earth's shadow
| Is always revolving in the ecliptic, 1t is
evident that in order for it to envelope the
| moon the latter must be in either one of
her nodes. But the difficulty in planning
the matter is to have the revolving shadow
there too. Both shadow and moon must
travel through one o. the nodes s.sss at the
That is the reason they are not OF more
frequent occurrence. The condition of
things as above stated is precisely that of
q grado crossing of two railroads. The
officials figure to prevent two trains from
crossing at the same time. In general they
are successful, but now and then collision
occurs. The astronomer calculates when
and where the moon and shadow will meet.
With him the, crossing" Is not fixed, for
even that also moves. But his problem is
just as definite as that of the railroad
man. AS for the calculation, 1t is a bit
more difficult while the result Is more GER
tain.4 IT, F.,
~ Entering the Shadow.
The penumbra is the region of partial
shadow Immediately surrounding the total;
within its limits portion Of the suns rays
are excluded. There Is a gradual grada-
tion from full light to complete shadow in
passing from the outer to the inner bound
airy of the penumbra.
At GAS this evening the moon enters this
penumbra, as is recorded above. The OBJ
server will not see any diminution of light
shadow. This is because the change Is SO
gradual that the eye cannot retain the
image Of the fully Illuminated satellite as
a standard of comparison. ~
As she enters the shadow at II pm.
portion Of her surface seems to be cut OFF
and to disappear almost entirely. A good
eye can notice, however, that the eclpsed
portion Is still very family and dimly out
lined.
When Total Eclipse Begins.
At 1906 am. the moon passes wholly into
the shadow. or total eclipse begins. Now
that there is none of the partly illuminated
disk visible, the whole surface is plainly
This light is refracted, or bent into the
shadow by the earth's atmosphere. and re-
f1ected back to US from the lunar surface.
At 1881 the middle Of the eclipse occurs,
at which time the moon is most deeply i'm
mersed.
The remainder Of the schedule refers to
the EMERSON from shadow and penumbra,
which will occur with precisely the same
effects, but in the reverse order to the i'm
mersion.
In addition to knowing the time, the OBJ
server may be interested to know in ad-
vance about what position the moon will
occupy in the sky at any phase, Since the
moon is full at the middle phase, she Is
just opposite "Old Sor' in the heavens.
Hence at any hour, the moon will be ap-
proximately where the sun was at the same
hour this forenoon.
occur shortly before II o'clock pm. Hence
the satellite will be about an hour east
of our meridian.
Tha observer need not expect to note any
phase with precision enough to determine
his time with accuracy, Stree the outlines
of the shadow are not sufficiently distinct.
But he may get his observed times of be-
ginning and ending of totalty to agree
with the above schedule within a minute
or two, If his watch Is correct.
The moon will traverse the shadow from
west to east, as is always the case. In
this instance the passage is nearly central,
being a trife below the axis Of the shadow
cone.
For phase H. to find where the shadow
will begin to impinge upon the moons cir
conference, or limb. as 1t is called, proceed
as follows: Two or three moments before
II pm. face the moon with watch, suspend
ed by chain or cord, so that the figure XII
Is uppermost and the VI nearest the
ground. Then compare the uppermost point
of the moon to the XII point of the watch.
and the 4S-minute point of the watch will
show where the shadow will enter luna's
face.
Similarly, for phase VI. the last contact
with the shadow, observe the same in
structions, and the 24-minute mark will
indicate the point where the shadow finally
withdraws.
Barring the Intervention of clouds, the
eclipse tonight viii be visible at Washing
ton. and generally the beginning in the
western portions of Europe and Africa in
the Atlantic ocean, North and South Amer
lea and the Eastern Pacific ocean, and the
ending in the Western Atlantic ocean,
North and South America and the Pacific
ocean.
VIII Bolt Hursts Nomination.
From the Baltimore Sun.
Ex-Mayor Robert T. Banks is another
democrat who says he will not support the
nomination of Mr. John E. Hurst for gov
ernor. He goes further, and says he will