The Madison daily leader. [volume] (Madison, S.D.) 1890-current, 1914-06-16
WIDE INTEREST IN
ECLIPSE OF sun
Hope to Solve Mysteries Of
the Solar Corona.
BIG CHANCE FOR SCIENTISTS

With Wonderful Instruments of the
Present Day to Help They Expect to
Determine Composition of Great Orb
That Lights the World-Noted As.
tronomer Describes Phenomenon.
The eclipse of the sun on Aug. Fl
next-total in part of Europe and Asia
and partial in northeastern America
is attracting widespread attention of
astronomers and scientists, various ex-
petitions being arranged to witness
the phenomenon. One of the most i'm
portant OF these will be that from the
Lick observatory, whose station will
be established about fifteen miles east
of Kiev. Russia. as nearly as possible
upon the central line OF the shadow
path.
The shadow path will begin at sun
rise In the Arctic ocean just off the
northern coast line of British CoIum-
bia. In longitude 121 degrees. 1t will
pass easterly across Greenland and
thence southeasterly over Norway.
Sweden. Russia. the Black sea and
Persia. ending at sunset In northwest
ern India.
In view of the public interest in the
event Professor G. G. Abbott, head of
the astronomical branch OF the Smith
sonian institution and a recognized au-
thority on solar phenomena, gives the
popular account of the eclipse and the
scientific results sought from such
events.
Fully Visible In Europe.
On Aug. Fl the moon will pass ex.
actly between the earth and the sun.
and there will be a total solar eclipse.
Ii will not be observed In America ex-
cept as a small partial eclipse at sun
rise In the northern states and Canada.
but In Persia, Russia and Scandina-
via the full effect will be seen.
Although the moon looks about the
same size as the sun, IL Is very much
smaller and nearer The sun is 1885,
600 miles In diameter and 100000
miles away, while the moon is 2,163
miles I'm diameter and $4,000 miles
away. On account OF the moons small
size compared with the u the shad-
ow cast by the moon is a cone, and
the point OF this cone just barely
reaches the earth.
In the August eclipse, which will
last two minutes fourteen seconds,
the diameter of the cone at the earth's
| ourfaoa ya apIy aho,t atgh%v Ave- po4ioo
SO that the eclipse Is visible as total
only In a belt about eighty-fve miles
wide, stretching over the countries
named above. The important cities of
Bitlis. Trebizond. Kiev, Minsk and
Riga lie near the center OF this belt.
Ii passes about a hundred miles north
Of Stockholm and Trondhjem. The
/ eclipse will be seen as partial over a
very wide area. including northeast
ern America. Greenland, Europe. half
OF Asia and half of Africa. Within
this resscn only a portion Of the suns
| disk will be hidden by the moon.
The purpose of all the expeditions Is
to observe those parts of the sun which
cannot be observed except at times of
/ total eclipse and likewise certain other
phenomena OF the suns surroundings
which demand a darkened sky. Inter
est always centers In the solar corona.
a magnificent structure extending out
wardly In all directions from the
| spherical body which the world sees
every clear day. many of the streamers
Of the corona having a length equal to
three OF four diameters Of the sun.
II need scarcely be said that the pur-
pose OF the observations Is to deter
mine the chemical composition of the
corona and Of the outer strata of the
suns atmosphere and the physical con
ditions existing therein.
To Photograph the Corona.
Several astronomers have tried TO
solve the problem Of securing coronal
observations without eclipses, but they
have failed totally. The Croker expe-
dition from the Lick observatory, o
clear sky permitting. will secure pho
tographs OF the orona on q large scale
with a Gamers forty feet In focal
length. and on a small scale with a
camera Of seventy inches focus. Other
photographs Of the corona will be
made by of special apparatus
designed to test the quality of the
light proceeding from the coronal
structure; whether this light proceeds
from incandescent materials In the
corona. or whether 1t originates in the
sun itself and Is reflected or diffracted
to us by comparatively cold gases or
concrete particles forming the corona.
The spectrum OF the corona and OF
the higher strata in the suns atmos-
phere will be studied by means of Ave
| spectrographs.