Evening star. [volume] (Washington, D.C.) 1854-1972, 1905-08-29
Rarity of Total Eclipses.

In spite of the frequency of the occur
renee, as a matter of fact there has only
been one total eclipse of the sun seen in
the eastern states since the end of the
eighteenth century, and In London, before
the eclipse of 1751 there had not been
single one visible for more than six CEN
turtles Eclipses are Of two kinds-those
of the sun and those of the moon. The
eClipses of the moon occur when that lum-
nary gets in the shadow cast by the earth
from the sun. Eclipses of the sun occur
when the earth passes through the shadow
made by the moon from the sun. But total
solar eclipses are extremely rare in any one
place on the earths Surface, compared with
the actual frequency of their occurrence:
In the last century, for example. total
eclpses of the sun were visible somewhere
in the United States only IN the years
1906 1884 1860, 1869, 1873, 1880, 1883, 1900.
But by observation and mathematical de-
duction astronomers have calculated just
where all total eclipses viii be seen, and
they have already worked out with nearly
equal precision as the eclipse for tomorrow
Just when and where the eclipse of the
year 2O12 will be seen. In the United
States five ecIipses will be visible January
"a 1925, and August 81, 1882. In the Philip
pines two extraordinarily long darkenings
of five and seven minutes. respectively. VIII
occur%May 8, 1929, and June 20, 1850, this
last probably the longest totality that hu-
mainly will witness for thousand years.
Problems for Investigation.
The main problems for investigation can
be divided as follows: First, the corona,
what IS It? and, second, the suns atmos-
phere what are the conditions of the gases
which compose 1t and how high do they
extend above the surface of the sun? There
are great many others an understanding
of which would greatly help to decipher the
enigma of the sun Itself. Beyond these
the discovery of what Is known as inter-
mercuria! planets by means Of photography
is possible. While Washington is not vouch-
safed the spectacle in all its majestic glory,
many Washngtonan are engaged at more
fortunate locations In expert observation
of the phenomena. AS has been previously
United States Naval Observatory are 10
Gated at Daroca and Porto Coeli, SPAIN
and Bona, Africa. With Admiral Chester,
also is Prof. Frank II. Bigelow of the
weather bureau, who will collect meteoro-
logical data. Prof BigeloW has been sent
out by the chief of the bureau. Prof. Moore
with the permission Of Secretary Wilson, to
establish temporary stations along the line
of totally TO observe atmospheric phenom-
ena. At the bureau the object of the ex-
petition Is said to be to find out how much
the air is cooled by the shading of the sun.
The streak of shadow makes cool sheet
of air, and this must flow out. letting the
warmer air take its place. The circulation
of air caused by this action may cause
storms or merely clouds. The iuctuation of
atmospheric temperature should enable the
observer to determine how much heat IS
derived from the SUM- and, since this heat
Is the source OF all atmospheric motions
to enable the student to get closer to the
foundations for ali meteorology.