Archimedes Texts

382
motions, by making them different in the times of the Sol
stices, as to greatnesse, from what they are in the Equinoxes.

We will speak (in the first place, of the diurnal motion, as
being the principal, and upon which the Moon and Sun seem to
exercise their power secondarily, in their monethly and annual

alterations. Three differences are observable in these horary
mutations; for in some places the waters rise and fall, without
making any progressive motion; in others, without rising or fal
ling they run one while towards the East, and recur another
while towards the West; and in others they vary the heights
and course also, as happeneth here in Venice, where the Tides in
coming in rise, and in going out fall; and this they do in the ex
termities of the lengths of Gulphs that distend from West to
East, and terminate in open shores, up along which shores the
Tide at time of flood hath room to extend it self: but if the
courfe of the Tide were iutercepted by Cliffes and Banks of
great height and steepnesse, there it will flow and ebbe without
any progressive motion. Again, it runs to and again, without
changing height in the middle parts of the Mediterrane, as nota

bly happeneth in the ^{*} Faro de Messina, between Scylla and Ca
rybdis, where the Currents, by reason of the narrownesse of
the Channel, are very swift; but in the more open Seas, and
about the Isles that stand farther into the Mediterranean Sea, as

the Baleares, Corsica, Sardignia, ^{*} Elba, Sicily towards the Affrican

Coasts, Malta, ^{*} Candia, &c. the changes of watermark are
very small; but the currents indeed are very notable, and espe
cially when the Sea is pent between Islands, or between them
and the Continent.

Now these onely true and certain effects, were there no more
to be observed, do, in my judgment, very probably perswade
any man, that will contain himself within the bounds of natu
ral causes, to grant the mobility of the Earth: for to make the
vessel (as it may be called) of the Mediterrane stand still, and to
make the water contained therein to do, as it doth, exceeds my
imagination, and perhaps every mans else, who will but pierce
beyond the rinde in these kind of inquiries.

SIMP. These accidents, Salviatus, begin not now, they are
most ancient, and have been observed by very many, and several
have attempted to assigne, some one, some another cause for the
same: and there dwelleth not many miles from hence a famous
Peripatetick, that alledgeth a cause for the same newly fished out

of a certain Text of Aristotle, not well understood by his Ex
positors, from which Text he collecteth, that the true cause of
these motions doth only proceed from the different profundities
of Seas: for that the waters of greatest depth being greater in