Archimedes Texts

231
tated and drove about by the Winds, which
push on the Waves in great Rows to the Shore,
where if they meet with Opposition, especially
from any hard rugged Body they beat against
them with their whole Strength, and being
dashed back again they break, and falling from
on high with continual Repetition dig up and
demolish whatever resists their Fury. A full
Proof of this is the great Depth of Water
which we constantly find under high Rocks
by the Sea-side. But when the Shore runs off
with an easy Descent, the raging Sea not find
ing any Thing to exert its Force against, grows
quiet, and falls back less furious upon itself;
and if it has brought any Sand along with it,
leaves it there; by which Means we see such
Shores growing higher and higher into the Sea
every Day. But when the Sea meets with a
Promontory, and afterwards with a Bay, the
Current runs impetuously along the Shore, and
turns back again upon itself; which is the Rea
son that in such Places we frequently meet with
deep Channels cut under the Shore. Others
maintain, that the Sea hath a Breath and Res
piration of its own, and pretend to observe,
that no Man ever dies naturally but when the
Tide is going off, whence they would infer, that
our Life has some Connection and Relation
with the Motion and Life of the Sea: but this
is not worth Dwelling upon. It is certain, that
the Tides rise and fall variously in different
Places. The Negropont has no less than six
Tides every Day. At Constantinople it has no
other Change but by flowing into the Pontus.
In the Propontis the Sea naturally throws upon
the Shore every Thing that is brought down
into it by the Rivers: because every Thing
which is put into an unnatural Agitation rests
of Course where-ever it finds a Place which is
not disturbed. But as upon almost all Shores
we see Heaps of Sand or Stones thrown up, it
may not be a miss just to mention the Conjec
tures of the Philosophers upon this Occasion.
I have said elsewhere, that Sand is form'd of
Mud dried by the Sun, and separated by the
Heat into very minute Particles. Stones are
supposed to be engendered by the Sea-water;
sor they tell us, that by Means of the Sun's
Heat and of Motion, the Water grows warm,
dries, and its lighter Parts evaporating hardens
into a Consistence, which grows to have so
much Solidity, that if the Sea is but a little
while at rest, it by degrees contracts a slimy
Crust, of a bituminous Nature; this Crust in
Time is afterwards broken, and by new Motion
and Collision the new-made Substance becomes
globular, and grows somewhat like a Spunge:
These globular Spunges are carried to the Shore,
where by their Sliminess they lick up the
Sand which is put into Agitation, which again
is dried and concocted by the Heat of the
Sun, and by the Salts, till by Length of Time
it hardens into Stone. This is the Conjecture
of the Philosophers. We frequently see the
Shore grow higher and higher towards the
Mouth of Rivers, especially if they flow through
loose Grounds, and are much subject to Land
floods; for such Rivers throw up vast Quan
tities of Sand and Stones before their Mouths
into the Sea, and so lengthen out the Shore.
This manifestly appears from the Danube, the
Phasis in Colchis, and others, and especially in
the Nile. The Ancients called Ægypt the
Nile's House, and tell us, that it was formerly
covered by the Sea quite as far as the Pelusian
Marshes. So it is related, that a great Part of
Cilicia was added to it by the River. Aristotle
says, that all Things are in perpetual Motion,
and that in length of Time the Sea and the
Hills will change Places with one another.
Hence the Saying of the Poet:

All that the Earth in her dark Womb conceals,
Time shall dig up and drag to open Light.

BUT to return. The Waves have this par
ticular Property, that when they meet with any
Bank which resists them, they dash against it
with the more Fury; and being beaten back,
according to the Height they fall from, the
more Sand they root up. This appears from
the great Depth of the Sea under the Rocks, a
gainst which they beat with much more Vio
lence, than they fall upon a soft and sloping
Sand. This being the Case, it requires great
Diligence and the most careful Contrivance to
restrain the Rage and Strength of the Sea,
which will many Times defeat all our Art and
Ability, and is not easily subdued by the Pow
er of Man. However, the Sort of Work which
we formerly recommended for the Foundati
ons of a Bridge may be of some Service in this
Case. But if it is necessary for us to carry
out a Pier into the Sea in order to fortify a
Port, we must begin our Work upon the dry
Ground, and so by Additions work it forwards
into the Sea. Our first and greatest Care must
be to chuse a firm Soil for this Structure; and
where-ever you raise it, raise it up with a
Slope of the lightest Stones that can be got, in