Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/411

 motions, by making them different in the times of the Solstices, 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 falling 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 extermities 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 course of the Tide were intercepted 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 notably happeneth in the *Faro de Messina, between Scylla and Carybdis, 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 especially 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 natural 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.

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 Expositors, 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