The Abbeville banner. [volume] (Abbeville, S.C.) 1847-1869, 1858-03-11
THE TIDES.


The tides Of the ocean have been Il
subject Of wonder and puzzle to those who
have not investigated their cause. 1t is re.
lated Of the soldiers of Alexander the Great,
who were natives of the Mediterranean
shores, that when they reached the confines
Of the Indian Ocean, AMI saw its waters
rolling up to Il great height and then flow
Ing back, twice every day, that they became
alarmed, and attributed the phenomena to
Il sp cial intcrpositon of the dctics of
the country which they had invaded. Va
| rlous remarkable theories have been advanc-
ed regarding the causes Of the tides Helper,
the celebrated German astronomer believed
that the carih WAS Il real living animal, that
the tides were due to its respirations, and
that men and brutcs were like insects
feeding on its back. The It'd, of the
! ocean have also been attributed to the wa
tcrs OF the ocean running in and ont
through some great hole at each pole, COM
mu"ica'ins by subtcrranean passage
through the earth and the M;cstrom-
now myth--that whirlpoo on the coast
of Norway, has been suggested rs IN open
ing into this supposed underground canal.
We would not be very much surprised if
some speculative being would yet discover
that the cold water found hy Lieutenant
li0rryman, rs described in our last number.
WAS melted ice that had come from the
Arctic regions through this inner passage,
and had oozcI out near Bermuda. Ii the
tides were due to the brcalhings of a great
monster OF course, we can suppose that it
just rcsp'rcd twice every twcnty-four hours,
hut this never could account for the vari:.-
tons Of the tides. The hole through the
earth also cannU: account for these vari;,.
tons, as this theory must involve the neces-
Sily OF Il regular ocean current running
round and round, not ebbing and flow
ing.
Many persons according to letters some
times received 10y us-still seem to be much
P"rrlcxcd with the phenomena of the tides.
ltcy cannot understand why they are higher
ut one time than another, nor why they
rise to the height Of sixty feet in the Bay
Of Fundy, forty feet in the ports Of Bristol,
Eng land, and st. MaIo, France, and only
rise TO Il few feet in New York and other
places, while they are scarcely pcrceptiLlc
III the Baltic and other seas. Descartes
WAS the first philosopher who advanced the
theory that the tides were due to the influ-
cncc OF the moon, bat Newton was the first
who worked out the problem, and discoy-
cred the true cause. Descartes believed
that the moon acted OH the waters of the
ocean by pressure. Newton demonstrated
that it acted upon the ocean by attraction;
that instead of pressing the waters, :. rolled
them up directly under it, and also ut its
antipodes at the same timc thus producing
the two tides every day. The tides are
caused by the attraction of both the moon
and the sun. If this earth had no moon,
the attraction would produce two tides
every day, but the cbb and flow would take
place at the same hours regularly, not vary
ing as they do now; these tides would be
also much smaller than those of the
moon.
Although the mass of the sun is far great
CT than that of the moon, and although at
traction is in proportion to the mass, yet it
is also invclscly as the square of the distance.
AS the sun, therefore, is four hundred times
farther distant than the moon, the attrac-
tinn of the waters Of the sen towards the
sun is found to be about three times less
than that of the moon the tides produced
hy the sun would therefore be three times
less than those of the moon. There arc
really two ocean tides, the lunar and the
solar, the latter is absorbed by the former,
which is wholly observable in respect to time
the solar only y rs it influences the height OF
the tidal wave. That caused by the moon
Is three times greater that that of the sun,
and it follows the moons motion around
the earth, rising and falling every twelve
hours, and each succeeding tide by three
quarters of an hour later than the prccc-
ding = :, exactly in accordance with the po-
slti"is of the moon or rs it is commonly
called, its rising and setting"
y Sometimes they are very low and at
other times very high tides-,hat is,e their
height is not uniform. This is caused
the positions Of the sun and moon rel:
to the earth. Thus, rs at the time Of
new moon, the sun and the moon bein
the same parts of the hcavens--the
produced in ocean are then tho .hig