Yorkville enquirer. [volume] (Yorkville, S.C.) 1855-2006, 1869-07-29

-Slost of yeur readers arc already aware that on
the III of August next, viii OCCUR an eclipse of
the sun. This eclipse will be the most remarkable
that will be. visible here daring the remainder of
the; present century. Many Of US have never wit
nessed and will navcr witness similar one.
Tho interest new manifested in such phenomena
is entirely different from what it was in former
times. Then' ignorance and superstition looked
with trembling gaze upon an eclipse as some evil
portent How different the case now? The un-
lettered man scarce gives it thought, or turns
aside from his daily avocation to bestow look up.
on it; butthe man ofiscence u deeply interested
Not only does he devote time to its prediction and
minute investigation, but he expcnds money freely
to prepare himself for favorable observation, and
frequently he travels hundreds of miles, to place
himself where he can view it to the best advantage.
Several European governments and scientific asso.
Citations sent ntexpedtphs to Africa to make obser-
tyear. 9T Congress has also appropriated FIVE
thousand dollars to make observations upon the
approaching eelipse5 and as-the time draws near,
MANY private observing parties win set out for "a
vorable points, and will alxiousy desire clear day;
since cloud would make hH their expense and
painstaking fruidesi
Many; no doubt, are ready to ask: "Wherefore
this waste?" What is therein such phenomena
worthy Of much thought and attention? 1t should
known, that is only by such diligence, enthu
dasn, perseverance and sacrifice of bodily comfort,
that those attainments in Astronomy have been
made, by which we are all benefited more or less,
but nome more So than the navigator, who now ira
verses heoceah with as much certainty as we tray
el to the next town hisdaily position being as
certalned by the movements of the heavenly bodies
Let me give some idea of What the astronomer has
to accomplish. He must reduce to order the mo-
ions, real and apparent, of the CELESTIAL bodies
These motions, 10 the compoh observer, are COM
picdted enough, but to the acute vision of the as
trononher, furnished with delicate Instruments the
irregularities of thesemotions are so numerous and
intricate, that any mind but that of the patient
mathematician, would give DIP in despair the task
Of reducing to order, or estimating tire effect of
these Irregularities The motion ofthe moon, for
instance, is subject TO at least fifty disturbing in
|Auences so that instead of her traversing as com.
niohy supposed, the same path through the heav-
ems, in regular curve with uniform motion, she
moves with varying velocity In an irregular wavy
curve, which never returns into ITSELF
Now when the astronomer has, by his compdta-
tions, founded upon observation and theory, re-
.duced to a tabular form these many disturbing
forces 50 that we may easily assign to the sun
and moon their exact places in the sky at any de-
sired period is it not natural that he should look
with jptense interest upon phenomenon which
confirms his calcul ulations and yerifes his work?
The Joy of success experienced in such case is
Known to the mathematician alone; but the bene-
fits of his toll are reaped by ALL
Before giving particular account Of the ap-
preaching eclipse, let me give plain explanation
of eclipses generally. When any Opaque body OBJ
structs thelight Of luminous object, that Opaque
body "eclipses' the light, and any object in the
shadow of said body is ''eclipsed." The earth and
the moon, both being opaque, cast shadows behind
them in objection opposite from the sum- which
is the ''great light" The sun being much the
largest body, these shadows are conical, and the
length of the cone Of shadow will depend upon the
distance of the sun The-nearer the earth or moon
to the sun the shorter the shadow. If the moon
passes through the earth shadow, she is said to
be eipsed but if tho earth passes into the shadow
of the moon, there is then what we call an eclipse
of the sun, but to an observer on the moon, it
would be an eclipse of the earth, and in appear
ance would be exactly like our lunar eclipse, only
on q more magnificent scale; owing to the earth's
being so much larger.
If the moon 8 apparent path through the heavens
conceded with that Of the sun, we should have
eclipses of the sun every new aloon and eclipses
of the moon every time she is full. But as these
paths cross at an angle of aboutfy degrees, and
also by reason of the varying cones of shadow,
eelipses comparatively rare, and when they do
occur, It can only be at or near the two crossing
points or nodes, as they are termed. Frequently
the moon passes these nodes without being eclips-
ed, but the suH, moving more slowly, never passes
the moons nodes without being more or less &C.
lipsed Hence there must he at least two eclipses
ofAhe sun every year, while there may be no lu-
mar eclipse; yet since the latter II visible 10 more
than one e.haf of the earth, while solar eclipse is
limited to very small part Of the earth's surface
its occurrence at any particular place is compara-
lively rare. This fact together with the consider
alton that the phenomenon occurs in the day time
and that large eclipse presents an unusual ap-
pearanee, renders it the more interesting; even
rbrutcs being more or less affected by it.
/. BY reason Of the nearness of our moon, and the
diurnal rotation of the earth, the same eclipse will
net appear precisely alike at any two places; and
to predict its appearance at any particular locality
an independent calculation must be made for that
locality.
fthc apparent size of the moon is less than
that of the sun, solar eclipse will be annular; but
ifcqual to- or greater than the sun, as in the pres
ent instance it will be total somewhere. Of course
only those places which are on Or near the central