The Manitowoc pilot. [volume] (Manitowoc, Wis.) 1859-1932, 1882-03-16
PREHISTORIC TIDES.

AT present the moon is 24O, 900 miles
away; but there was a time when the
moon was only one sixth part of this, or
say 1000 miles away. That time must
have correspondent to some geological
epoch. 1t may have been earlier than
the time when Cocoon lived. 1t was
more likely to have been later. want
to point out that when the moon was
only 10000 miles away we had in it a
geological engine of transcendent power.
If the present tide be three feet, and if
the early tides be 216 times their present
amount, then it is plain that the ancient
tides must have been 648 feet.
There can be no doubt that in ancient
times the tides of this amount, and even
tides very much lower. must have occur
red. / ask the biologists to take account
of these facts, and to consider the effect
"a tidal rise and fall of 64S feet twice
every day. Dwell for one moment on
the sublime spectacle of tide 64S feet
high, and see what an agent it would be
for one performance of geological work
We are now standing, I suppose, some
500 feet above the level of the sea. The
sea is good many miles from Birming-
ham, yet if the rise and fall at the coasts
were 648 feet, Birmingham might be as
great seaport as Liverpool. Three
quarters tide would bring the sea into the
streets of Birmingham. At high tide
there would be about $50 feet of blue
water oyer our heads. Every house
would be covered, and the tops of few
chimneys would alone indicate the site of
the town.
In few hours more the whole of this
vast food would have retreated. Not
only would it leave England high and
dry, but probably the Straits of Dover
would be drained, and perhaps even Ire
land would, in a literal sense, become a
member of the United Kingdom. A few
hours pass, and the whole of England is
again inundated, but only again to be
abandoned.
These mighty tides are the gifts which
astronomers have now made to the work
ing machinery of the biologists. They
constitute an engine of terrific power to
aid in the great work of geology. What
would the puny efforts of water in other
ways accomplished when compared with
these majestic tides and the great cur
rents they produce?
In the great primevel tide will probably
be found the explanation of what has
long been reproach to geology. The
early paleozonic rocks form stupendous
mass of ocean made beds, which accor-
ding to Professor Williamson, are twenty
miles thick up to the top of the silurian
beds. 1t has long been a difficulty to
conceive how such gigantic quantity of
material could have been ground up and
deposited at the bottom of the sea. The
biologists said: "The rivers and other
agents OF the present DAY Will do IL II
you give them time enough But, un-
fortunately, the mathematicians and the
natural philosophers would not give
them time enough, and they ordered the
biologists to ''hurry up their phenome-
ia. The mathematicians had other
reasons for believing that the earth could
not have been SO old as the biologists
demanded. Now, however, the mathe.
maticians have discovered the new and
stupendous tidal grinding engine. With
this powerful aid the biologists can get
through their work in a reasonable period
of time, and the biologists and the
mathematicians may be reconciled.-
Lecture by Prof. Ball.