Chapter XVII.

Of Tides, or of the Ebbing and Flowing of the Sea.

Aristotle and Heraclides say, they proceed from the sun, which moves and whirls about the winds; and these falling with a violence upon the Atlantic, it is pressed and swells by them, by which means the sea flows; and their impression ceasing, the sea retracts, hence they ebb. Pytheas the Massilian, that the fulness of the moon gives the flow, the wane the ebb. Plato attributes it all to a certain balance of the sea, which by means of a mouth or orifice causes the tide; and by this means the seas do rise and flow alternately. Timaeus believes that those rivers which fall from the mountains of the Celtic Gaul into the Atlantic produce a tide. For upon their entering upon that sea, they violently press upon it, and so cause the flow; but they disemboguing themselves, there is a cessation of the impetuousness, by which means the ebb is produced. Seleucus the mathematician attributes a motion to the earth; and thus he pronounceth that the moon in its circumlation meets and repels the earth in its motion; between these two, the earth and the moon, there is a vehement wind raised and intercepted, which rushes upon the Atlantic Ocean, and gives us a probable argument that it is the cause the sea is troubled and moved.