The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1897-07-28
WATCH FOR THE ECLIPSE.
May BE Seen Between and O'Clock
TO-MOrrOw Morning.

Tomorrow morning there will occur
rare and beautiful eclipse of the sun of
considerable magnitude, and plainly visi-
BILE throughout this country and the
greater part of South America. The eclipse
will be partial here, but in Mexico, Cuba
and the Atlantic ocean it will be what is
known as an annular eclipse, or one in
which the sun is not quite obscured, but
a thin ring of light is left along the edge
of the sun while the central portion is
completely hidden by the moon.
In indianapolis the eclipse will begin
about 7:40 o'clock and continue an hour
or an hour and a half. If the weather is
fair it is calculated that the eclipse should
be plainly visible in this section. simple
plan to aid in observing the eclipse, in case
the sun shines too brightly, is to smoke
piece of smooth glass by holding it over
the flame of an oil lamp. Ordinary colored
sun glasses will answer the purpose very
well.
The first contact will occur on the west
ern limb of the sun, ninety degrees from
the north point, and the last contact on
the eastern limb 1872 degrees from the north
point. About three-fourths of the suns d.
ameter on the southern side Will be op-
scured, leaving the sun in the shape or
crescent like the moon about Tour Gays
after new moon
Notwithstanding the fact that more than
one-half of the sun will be hidden from
view. but little apparent change will be
noticed in the quantity or the character or
the light. The sun is such a dazzling bright
object that only small portion of its Visi-
BILE disk is sufficient to flood the world with
light.
A slight haziness of a peculiar character
may be noticed, but otherwise nothing of
an unusual nature may be expected. The
self-registering thermometer at the signal
office may show slight dip in the tenn
perature curve, for about one-half of the
suns heat will be cut off for some time.
This is one of the interesting scientific OBJ
servation that should be carefully made
and recorded at every weather bureau Of
flee.
Every one knows that eclipse of the
sun is caused by the moon passing between
the earth and the sun, by which all or a
portion of the light is cut off. The moon
is very much smaller than the sun, but
owing to it's lesser distance the moon pre-
SentS about the same visual angle as the
sun and appears to be about the same size.
At the moons average distance from us 1t
is just about large enough to cover the
sun up, but as the distance of both the sun
and moon from us constantly vary, we have
sometimes a total eclipse and at other
times an annular eclipse In total eclipse
the moons shadow is long enough to reach
to the earth, while in an annular eclipse,
such as the present one, the shadow does
not quite reach US.
Owing to the fact that the sun is much
larger than the moon the shadow of the
latter terminates in q point, which during
an eclipse drags across the earth's surface
in a comparatively narrow path never more
than 10 miles wide
This pointed shadow is called the umbra,
within which the observer would expert
this umbra is a fainter shadow called the
penumbra within which an observer would
experience partial eclipse such as will be
visible here tomorrow.