Omaha daily bee. (Omaha [Neb.]) 187?-1922, 1916-06-03
The Mystery Of the Tides
By GARRETT P. sERYss.

"a 7 i
wv giant that stretches his vast length
around all our coasts whose breath is the
flood Of waters, now poured impetuousy INTO
every bay and inlet az the monster exhales and
now swiftly drawn out again with his next inha-
lation, while, concidentally, his broad breast
heaves and falls and rhythmicaliy the naves rise
and sink, feeling the resistess power of the life
that slumbers underneath their kees.
But is is forced breathing, this Of great Nep-
tune and he would lie still as death but for two
life-savers in the sky which strive without ceas-
ing to save him from suifocaton through the
stagnation Of his own waters.
These Samaritans are the moon and the sun,
as every school-child is taught without under
standing, just most Of us know that pull
motor may bring a drowned to life again
without comprehending exactly how.
This is the mystery Of the tides, and mys-
terry II remains, in part, although mankind has
wondered about II and studied It from time inn
memorial. Although it had been noticed long
before Newton was born that ehere was syn
chronism between the motion OF the moon and
the tides yet II was not until he had developed
his theory Of gravitation that the manner of the
moons action in producing tides became plain
The moon is the principal agent, more than
twice as effective as the sun, and since they both
work in the same way, II is unnecessary to intro
duce more than one Of them in simple explana-
ton.
That explanation depends upon three proved
faets-hrst, that the attraction Of gravitation in
creases in force with decrease of distance; sec
ond that the solid earth yields as whole, united
body to the gravitational pull OF the moon, and
third, that the ocean, being composed of watery
particles free to move among one another, does
not yield to the lunar tug a whole united body
but its waters flow over the earth's crust toward
the place where the resultant of the forces acting
upon them is greatest
The consequence is that they are, in a sense
heaped or swelled up in tidal wave, and the
rotation Of the earth on its axis carries this wave
westward, or in direction contrary to that of the
rotation. &c. If you envelop school globe in
sheet OF gauze and hold the gauze so that il can
not turn with the globe when the latter is rotated
the gauze will move over its surface in op-
posite direction. Your hand gathering up and
holding the gauze on one side, may represent the
attraction Of the moon upon the oceanic waters
The water is heaped up by tie moons attrac-
ton in accordance with the first Of the three
fundamental facts mentioned above; namely, that
the attraction increases with decrease OF distance
In truth, II increases inversely as the square OF
the distance, which augments the effect The
side OF the earth that is at any time toward the
moon is about 1000 miles nearer the moon than
the center OF the earth.
But, according to our second fundamental fact
the earth yields as a single solid body, to which
we may now add that the effect OF the pull is the
same as If the entire substance Of the earth were
concentrated at its center. 1t follows that the
waters OF the ocean being free to move over their
solid bed, and experiencing an attraction greater
than that felt at the earth's center, tend to flow
toward the place where the moons attraction is
greatest
Now comes the point usually found most diff
heult to understand. There is a tide on the side
OF the earth turned from the moon as we'll as on
the side turned toward it. This is result OF the
same fundamental facts. The water the side
opposite to the moon is 1000 miles farther from
the moon than the center OF tine earth and is,
consequently, proportionately less attracted.
Thus the earth, a whole tends to be drawn
away from the water on that side, just as on the
other side the water tends to be drawn away from
the earth.
This Is, in substance the theory OF the tides,
and no doubt il is a true explanation OF their
fundamental cause. But great difficulties arise
when the theory is applied to the actual tides that
flow around the coasts OF tho continents. II the
earth were smooth sphere, covered everywhere
with an ocean OF unvaryng depth, there would be
no difficulties of the kind. But then we should
either not exist at all or else should be fish,
or whales, or sharks, and in that case, instead of
astronomers, physicists and mathematician we
should probably produce only big eaters.
Taking the situation as II is we find that the
tides play the deuce with the theory. They do
not disprove it, but they show that it is altogether
insufficient to cover the facts. The sources of the
trouble the varying depth of the water and
the subdivision OF the ocean into many different
seas, more or less completely separated by huge,
ODDLY shaped continents.
Because the human mind loves simplicity.
which is easy to understand and shrinks from
complications, persistent attempts have been
made TO force the tides into compliance with
uniform theory, but they refuse to submit
Thus Il has long been taught, in the text
books, that the tides are all associated parts of
one universal world phenomenon" We have
been told Of "a parent wave" starting in the
broad. deep waters OF the Southern Pacific and
gradually spreading round the globe, combining
oceans.
This parent tide has evep been imaginatively,
but with authoritative assertion traced around
distant oapes through straits and across the
length and breadth OF many seas. One textbook
writer has ayerred that this tide Z "forty hours
old" when il reaches Florida from the Pacific aud
nearly sixty hours old" when il begins TO wash
upon the shores OF the North Sea
Now, all this must be abandoned as pure spec
ulation. according 90 the Investigations OF our
coast and gcndetie survey Although. as Dr.
Charles Lane Poor aays. ethe theory that the
tides are a world phenomenon has the support
al tho worlds greatest mathematicians aud Ill the
prestige their names can lend" the Investigations
referred 20 seem 70 prove that the tides AYE
strictly local IN character and IN being and that
the tides Of the Atlantic ocean are due "a the 0s.
citations n the waters ol the Atlantic, iudspcnd,
snt 81 shat has happened, o. may happen. in the
waters 81 the Patihe'
Still nobody doubts thar the sun ard ths moon
are she rausefs ~ the tides hut neptune. instead
q heinz single appears a. multiple siant who
hreathes with nlanA MAteT1 angs