Middlebury register. (Middlebury, Vt.) 1886-1937, 1889-09-20

ODStrNHIlOn. IL Will De TOUR years DelOre an
other total eclipse occurs, which makes one
more reason for taking advantage of what is
about to happen.
Although astronomy is one of the very old
est of the sciences, and has made immense
strides in advance, it is only within a few
years that, by the aid Of the spectroscope
and photography, the nature of the sun and
its surroundings has been established with
anything like certainty and even at this date
the theories as TO the suns activity are widely
at variance. The halo Of light seen around
the black disk of the moon at total solar
eclipse was, until about twenty years ago,
thought to be due either to the effect pro-
duced by our own atmosphere or by the
moons atmosphere. Now astronomers are
convinced that this corona is part of the sun
itself, and that to it scientists must look for
the disclosing of the mysteries connected
with the suns light and heat.
Recent obse: vations of eclipses have made
it quite certain that the sun as ordinarily
visible to us, bounded by the photosphere, is
only part of the sun. Just outside the pho
tosphere is a comparatively thin layer of gas,
mainly hydrogen. called the chromosphere;
around this is the corona, thousands Of miles
thick, and around the corona there is con-
siderable extension of matter, about which
very little has been definitely determined.
The general theory that has been built up
from knowledge Of these facts, and from
the observations of such phenomena as sun
spots and prominences, is that the chemical
elements are being continuously tossed about
in the enormous atmosphere Of the sun, and
never getting out Of it. The outer layers of
this atmosphere are recognized as much cooler
than the inner. Cool masses of matter are
produced by condensation, and, Lgving gath
cred weight, come under the influence of q
gravitation over twenty-five times as pow
erful as our own, and fall with almost incred-
ible rapidity toward the center, and it is sup
posed that these terrific rains of cooled mat
ter produce what are called sun spots.
Astronomical computers have for ages been
able to determine the motions of the sun,
moon, earth and stars with sufficient accu-
racy to not only say when the various phe-
nomena will take place, but to give the ex-
act location best suited for observation. In
this eclipse the path of totality begins about
half way between the island of Hayti and
the northern coast of South America, ex-
tends in southeasterly direction, touching
the South American coast here and there,
until it reaches point in the South Atlantic
ocean almost midway between the islands Of
Ascension and ST. Helena, when it bends to
the northeast, passing over the island Of San
Paul de Loando, and so continues across
Africa, ending in dogs north latitude and
about 40 degs east longitude. The eclipse is
caused, as is well known, by the shadow of
the moon sweeping over the earth, the sun
being either wholly or partially obscured on
that part of the earth where the shadow falls.
The total eclipse is visible only to very
small portion Of the earth's surface, because
the distance of the moon changes 50 little
| from us that the earth can never be far from
! the vortex of the moons shadow as cast by
/ the sun. AS the moon moves around the
earth from west to east, its shadow moves in
the same direction, and the diameter of the
shadow at the surface of the earth ranges
from zero to $50 miles. 1t therefore sweeps
along a belt of the earth's surface of that
breadth, in the same direction in which the
earth is rotating, with velocity of 1900 to
2,l0O miles per hour. 1t may be inferred from
this that a partial eclipse is visible over
much greater portion Of the earths surface
than the total eclipse, to observe which the
observer must station himself beforehand at
some point Of the earth's surface over which
the shadow passes.
The point selected In this case as being
most favorable for the necessary observations
is the town of Muxima, on the Quinza river,
III AITlcd- Inc scleullsts Will ldDu at tne
island Of San Paul de Loanda, which is be-
tween two and three hundred miles from the
mouth Of the Congo, and will from there go
about 100 miles into the interior
The last session Of congress appropriated
5000 to defray the expense Of an expedition
Of scientists to be sent under the auspices Of
the secretary of the navy to observe the total
eclipse and at conference held in Washing
ton it was decided to divide the expedition
into two parties one under the direction Of
Professor Todd, of Amherst, already famous
for having conducted similar expedition 70
Japan two years ago, the other party to be
under the direction Of Mr.. Joseph Russell, OF
Washington, who is an expert in solar pho
Biography, and will be intrusted with the
duty of obtaining photographs of the eclipse
in its various phases.
Mr.. Russell has quite an established repu-
tation for devising instruments best adapted
to suit peculiar conditions of observation
and rejecting telescope for taking frequent
pictures Of the corona is in process of con-
struction under his supervision. He will also
have photometer for finding out how much
the total light of the coropa 10 equiv alent to,