Port Tobacco times, and Charles County advertiser. (Port Tobacco, Md.) 1845-1898, 1858-02-04
THE TIDES.

Hhe tides OF the ocean have been sub
|ject of wonder and a puzzle to those who
have not investigated their cause. It is re-
lated of the soldiers of Alexander the Great,
whe we're natives of the Mediterranean shores
that when they reached the confines Of the
Indian Ocean and saw it's waters rolling up
Ito q great height, and then flowing back,
twice every day, that they became alarmed,
and dattributed the phenomena to a special
intTpositien of the deities of the country
which they had invaded. Various remark
abls theories have been advanced regarding
theEoause of the tides. Kepler, the cele-
brated German astronomer, believed that
theharth was real living animal, that the
| tides were due to it's respirations, and that
men and beasts were like insects feeding on
Its back. The tides have also been attribu-
tedkto the waters of the ocean running in
OUT through some great hole at each pole
communicating by a subterranean passage
thRugh the earth; andsthe Maelstrom-
ne a. nyth4-that whirlpool on the coast Of
NORWAY, nas been suggested as an opening
into the supposed underground canal. We
wodld not be very much surprised if some
speculative being would yet discover that
the'very cold water found by Lieut.. Berry
man, as described in our last number, was
melted ice that had come from the Arctic
regions through this inner passage, and had
oozed out near Bermuda. If the tides were
due to the breathings of great monster, of
course we can suppose that it just respired
twice every twenty four hours, but this new
41o of %1o
tides. The whole through the earth also
cannot account for these variations, as this
theory must involve the necessity of regu-
lar ocean current running round and round
not ebbing and flowing.
Many according to letters some
times received by us-still seem to be much
perplexed with the phenomena Of the tides.
They cannot understand why they are high
er at 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,
England, and St. Mafo, France, and only
rise to few feet in height in New York
and other places, while they are scarcely
perceptible in the Baltic and other SEAS
Descartes was the first philosopher who ad-
vanced the theory that the tides were due to
the influence of the moon, but Newton was
the first who worked out the problem, and
discovered the true cause. Descartes be-
lieyed that the moon acted on the waters OF
the ocean by pressure; Newton -demonstrat-
ed that it acted upon the ocean by attrac-
tion that instead Of pressing the waters, il
rolled them up directly under it, and also
at its antipodes at the same time, thus pro-
ducing the two tides every day. The tides
moon and the SUM- If this earth had nc
moon, the attraction of the sun would pro.
duce two tides every day, but their ebb and
flow woold take place at the same hours re.
gularly, not varying as they do now these
tides would be much smaller than those o.
the moon Although the mass of the sur
is far greater than that of the moon, and al
though attraction is in proportion to the
mass, yetit is also inversely as the square o.
the distance AS the sun, therefore, is foul
hundred times further distant than the moon
the attraction of the waters of the sea towards
the sun is found to be about three times less
than that of the moon the tides produced by
the sun would therefore be three times less
than those of the moon. There are really
two ocean tides, the lamar and solar, but the
latter is absorbed by the former, which i:
wholly observable in respect to tine, tht
solar only as it influences the height Of tht
tidal wave. That caused by the moon il
three times greater than that of the sun
and it follows the moon motion around tn,
earth, rising and falling every twelve hours
and each succeeding tide later by thre
quarters of an hour than the preceding
one. exactly in accordance with the position