The Montgomery advertiser., 1909-06-17

will not be the great astronomical
event that some eclipses have been,
since 1t will be only partial except In
the Arctic regions. There 1t will first
take the form of an annular eclipse;
that 10. the moon will be too far away
to hide the whole face of the sun. the
edges OF which will appear outside of
the circumference OF the moon. Be-
fore 1t IL over the moon Will be far
enough away to completely cut "on the
sun from earthly view at the points in
the path of totality, and the eclipse
then will become total. Later stin II
will again become annular, after which
the moon will pass away from before
the face OF the sun. To America above
a line drawn from San Francisco TO
Corpus Christi. Tex. the eclipse will be
Invisible.
Perhaps the most remarkable fact
connected with eclipses Is that astron-
omers can predict them with an accu-
racy down to the very minute and for
centuries ahead, yet the state OF the
clouds cannot be foretold even sin
gle day. This has caused many we'll
laid plan for eclipse expeditions to go
awry, and the arrangements of months
and the expenditure Of thousands OF
dollars to go for naught. Periods of
total eclipse of the sun are great events
In the lives of those who wish to faith
ON the secrets of that great luminary.
There are about seventy total eclipses
of the sun in a century, and their ag-
gregate periods Of totality amount to
but little more than three hours.
Some Of these are only visible in re-
gions too remote for the astronomer
on the oceans Still others are OBJ
secured by clouds. so that the astron-
omer. has TO work and think fast when
a favorable opportunity does present
itself At most he has but seven min
utes on a given eclipse, and the aver
age is less than three minutes. The
width of the strip of territory over
which an eclipse may be total cannot
exceed 1877 miles, and II Is seldom Wild
err than l40 miles. Some parts of the
earth are more favored with total
ecllpses than other parts. London ney-
err saw a total eclipse In more than 5ou
years together while Venezuela saw
two in three years. New York has not
seen a single total eclipse IN CEN
fury, while Yellowstone Park had TWO
in twelve years.
Eclipse observations are less than
century old. In ancient times astron-
omers were not able to predict eclipses.
At Rome 1t was crime to talk, ABOUT
their being due to natural causes; they
were believed to be without the order
of nature. and to presage some dire
event. Even after astronomers learn
ed the secret OF eclipses the people at
large refused to believe It, 1t is said
that Thales was able to bring about
the peace between the Medes and the
Lydians by predicting an eclipse, and
that CoIumbu Impressed his heavenly
descent on the Jamaicans by showing
them that he could tell when an eclipse
would occur. In Justice to him 1t Is
to be said that he made, such claim
in order to get food for his men. Inc
reason that astronomers were so SLOW
in learning how to predict ecitpses ana
to explain them was that while they
occurred with regularity they occurred
at different places on the earth, thus
effectually hiding from the astronomers
the regularity of their occurrences.
The deep interest In the sun which
astronomers are now taking Is due
largely to the lessons they learned
through eclipses. Through them they
have learned about the corona, the
chromosphere, and the solar promi-
nences. These discoveries have stimu-
lated the most intense interest in the
study of the sun,5 and astronomers are
working a. they never worked peEore
to fathom the mysteries OF the great
orb to which ali earthly life owes its
existence. SO great has this interest
become that an International union for
co Operative research has been estab-
lished, and the astronomers OF the
world come together every few years,
forming a clearing house for the infor-
nation gathered between meetings
Much has already been learned about
the sun and the layman must wonder
and marvel at the genius OF the astron-
~. n kt n
knowledge which has been obtained.
Yet the astronomer thinks only of
what is yet to be learned, and the lit
tie he knows compared with what he
desires to find out. He will tell you
that 1t is important that he should
know more about the constancy OF the
sun. He has learned that the heat 1t
throws of varies from month to month,
yet he wants to know why. He has
discovered that there is relation be-
tween terrestrial magnetism and sum
spots. and probably between earth
quakes and sun-spots, but he wants to
know what that relation is. He
knows that a change of 10 per cent in
the radiation of heat by the sun would
result in a change of IL degrees in the
temperature OF our atmosphere.
Astronomers have been able to prove
to a certainty that the sun is approxi-
mately 100000 miles away from the
earth. They have three standpoints
from which this may be calculated, and
all give the same answer. They are
then in a position to tell how big the
sun is, and they place its diameter at
$4,000 miles. II 1t takes forty days
to go round the earth, at the same
speed 1t would take twelve years TO
travel around the sun. II the earth
were to swell to the size of the sun and
man should grow tall in proportion, he
would be about 625 feet high, or nearly
100 feet higher than the Washington
monument. If $50 pound man could
fly to the sun his weight there would
be about two tons, owing to the vast
increase in the force of gravity, due In
turn to the far greater size Of the sun
as compared with the earth.
1t is estimated that old Sol radiates
enough heat comfortably to provide for
two thousand million planets like our
own. Each square foot of his surface
gives OF enough heat to drive an
ocean liner, and two acres of the suns
surface would furnish power enough
to drive all the machinery in the world
now driven by steam. Its heat con-
centrated on a column OF ice two and
a fourth miles square and reaching
from the earth to the sun would suffice
to melt the whole column in a single
second. In seven seconds more the wa
ter from the melted column would be
vaporized. What becomes of all this
heat and light, ask the astronomers.
With only one billionth part of it used
by all the planets, do the other s9s,9s9.-
999 parts go on and on into empty
space forever, at the rate of 10000
miles a second? Is the sun SO prodi-
gal with it's heat that II uses only the
~ Onnh