Bismarck daily tribune. [volume] (Bismarck, Dakota [N.D.]) 1881-1916, 1914-05-19

shadow cast by the moon is a cone,
and he point of this cone just barely
reaches the earth.
Partial Eclipse Here. =. $50.
In the August eclipse the diameter
of tho cone at the earth's surface is
only about s. miles, so that the
eclipse is visible as total only in
belt about s. miles wide stretching
over the countries named above. The
important cities of Bitlis, Trebizond,
kief, Minsk and Riga lie near the
center Of this belt 1t passes about
a hundred miles north of Stockholm
and Trondheim. The eclipse will be
seen as partial over very wide area,
including northeastern America,
Greenland, Europe, half of Asia and
half of Africa Within this region only
q portion Of the suns disk will be
hidden by the moon.
Sky Becomes Dark.
Wherever the solar eclipse is seen
as total, the sky will become nearly
as dark as ful!-moonlight, and few
Of the brighter stars and planets may
be seen. The duration Of the totality
is longest near Kief in Russia where
it is 2 minutes l3 seconds. Sometimes
the moon and sun occupy such posi-.
tons that although the moon passes
directly between the earth and the
sun the shadow cone does not quite
reach the earth. Such solar ecipses
are called "annular" and are no.
where total eclipses. In the most fav-
orable case a total eclipse may last
over minutes at station, but such
occasions are very rare.
There will be total cclipses Wis
ible in the United States on June S,
1918, Sept. 10, 1923 and Jan. "a, 1925.
AS the glare of the sun in the sky
is removed, and yet the moon hardly
than covers the sun, it is possible at
times of total solar eclipses to see all
the celestial objects near the sun.
These can not be seen at other times
because they are lost in the bright
sky light. 1t is this which makes as
trOnomers SO eager to observe total
eclipses. The most striking thing
seen is the solar corona, beautiful
pearly light stretching away from the
sun In all directions, something like
the Aurora Borealis seen in northern
countries.
Short and Regular Corona.
| The corona extends from one to
three solar diameters away from the
sun. Its form changes from year to
year in connection with the number
of sun-spots which prevail. AS the
present year will be one of compara-
lively few sun-spots the corona is ex-
pected to have short but Well-marked
polar rays and long equatorial stream
ers. In 1918 total eclipse will be WIS.,
IDLE in the United States, and as the
,sun-spots will then be numerous the
corona will probably extend nearly
equally in all directions.
Formerly it was believed probable
that one or more planets of the solar
system exist nearer the sun than
Mercury, and it was hoped to dscov.
er these during total solar eclipses.
Eut the sky has been SO carefully
searched that no such. objects large
enough to be worth counting exist.
Lost Much Of Value.
Formerly also it was regarded as
necessary to wait for eclipses and to
see and study the beautiful rosy
flames Of hydrogen and other gases,
called prOminenccs, which surround
the sun. But these may now be OBJ
served at any time by means of
special apparatus. While value of to.
tai eclipSeS has therefore somewhat
diminished, there still remain many
studies which are confined to them.
Astronomers Make Plans.
Astronomers make very careful pre-.
parations, and rehearse all details Of
their programs lest some of the pre-.