Daily Kennebec journal., 1900-05-05
ECLIPSES OF THE SUN.
Where That Of May % May Best Be
Observed.
The Scientific Importance Of the Study oi
Eciipses.

common astronomical occurrence. The
sun will be totally cclpsed, and the
event will be visible in parts of the
United States.
Occasionally, as we know, the moon
passes between us and the sun, cut
ting off the latters light completely.
This We call a solar eclipse. Lunar
eclipses, on the other hand, are caused
by the moons reaching such a posi-
tiOn that the earth is directly between
it and the sun. The moon has no in
herent brilliancy like the sun; it shines
only by rejecting solar light to us;
and when that light is cut off, the
moon simply goes out" But the sun
is sclf-luminous. and is i'll reality shin
ing just the same when under eclipse
as at any other time. Thus we arrive
at this fundamental difference between
lunar and solar eclipses. In the
former, the moon having suddenly
ceased to receive or reflect light, the
eclipse is observable wherever the
the moon, if uneclipsed, would be visi-
Bile. But at any given moment we can
usually see the moon from one-half the
earth's surface. Consequently. if j
of the earth's inhabitants have an op-
portunity to observe it, and thus a
lunar eclipse is something that almost
any person can remember TO have
seen. But it is very different with the
sun. AS we have said he continues to
give light when eclipsed; so that it is
only in places where the sun is actually
covered up by the moon that he Will
seem to be eclipsed. The moon under
eclipse is like candle that has been
eXtinguished; it is dark from whatever
side We look at it. But the eclipsed
sun is like a burning candle, which will
be invisible to him only whose view is
ohstructed by the interpOsitiOn of some
opaque object.
That opaque object is the moon. But
she is comparatively small, and cannot
render the sun totally invisible from
more than a tiny circular or oval spot
on the earth's surface In the eclipse
Of May 2S. that little spot will be only
about seventy-five miles wide: and if
the moon We're not in motion, the total
phase of the eclipse could be seen no.
where else. But the moon is travelling
all the time through space in its orbit
around the earth. SO the little spot is
moving too, and changing its position
gradually upon the earths surface.
Thus. instead Of a spot. W. shall have
l long strip or band about seventy
five miles wide: and by waiting for the
right moment it will be possible to see
totality from any point within this
band. The whole thing is much as
though there We're huge pencil. with
its point touching the earth, and hav-
ing its other end pivoted to the sun. If
the moving moon We're then also at
tached to this pencil some where near
the point. she would draw the pencil
along and the point would trace out
the eclipse path on our earth. Anyone
standing in that path could then look
along the pencil. and at the proper
moment see the moon covering the
sun and obScuring his light. In
places situated near this path IF total
ity. as it is called, we shall br able to
src the eclipse. but not az 4 total one.
For such places the moon Will cover
the sun only in part, 50 that some of
his brilliant surface Will remain in
sight. The amount Of obstruction al
ways depends upon the Observers
nearer he is. the more nearly total the
eclipse viii be.
on May 3, the path Of totality be
gins in the Pacific ocean just west Of
Mexico. There the point Of the huge
pencil we have imagined first touches
our earth. 1t then passes eastward
across Mexico. and entering the
United States near New Orleans. pro
ceeds in nOrtheastcrly direction until
it leaves the continent close to Norfolk,
Va. Then it crosses the Atlantic,
touches Portugal, and afterwards
passes across northern Africa. leaving
the earth finally near the northern end
Of the Red sea. In this country, the
cities Of New Orleans. La. Mobile,
Ala. Montgomery, Ala, Raleigh, n. c.,
and Norfolk. Va, are all on the total
ity path. At New Orleans, the sun
will be completely covered at 7.30 A.
NJ, while at Norfolk this will not
happen until S.53 \. NJ. In the former
CITY totality will last seventy-threc
seconds. and in the latter 102 seconds.
At intermediate places hCth The time
ana duration Of totality will fail be-
tween these extreme values. For
places nearer To New ofIttlnS imam 10
Norfolk the numbers Will be nearer
those given for New Orleans, and vice
versa.
Having thus explained the circum-
stances of this eclipse, We shall now
touch upon some Of the interesting
things that will be seen if the sky is
clear. Total solar eclipSeS appeal
equally to the general public and to
the professional astronomer. On the
one hand. they present the most superb
spectacle within the whole range of
astronomy: and on the other. they
offer the best opportunity to study the
mysterious structure and composition
! Of our sun. one Of the things 10 which
astronomers attach importance is the
accurate observation of the times of
beginning and ending of the eclipse.
| It is easy to see that the mathematical
| considerations upon which are based
| nur theories of lunar motion Will be put
| to a very severe test in predicting the
| exact instant when the sun Will be
covered up by the moon. If observa-
ton agrees with prediction. W" have
| the strongest cOrrOborative evidence of
! the correctness of our theory and Of
our numerical calculations. ON the