CHAPTER I. OF THE FLOW AND EBB OF THE SEA.

...to begin a project related to the coast in order to proceed accordingly.

It is observed, for example, that in all straits, river mouths, and gulfs exposed to the east, the Ocean flows and ebbs The rising (flow) and falling (ebb) of the tide. from west to east, and from east to west; and that, on the contrary, it flows and ebbs from east to west and from west to east on all shores positioned to the west; and it is the same for others in the north and south, where the Ocean moves conversely from south to north and from north to south, and generally from all imaginable angles, depending on how the situation of other shores, river mouths, straits, and gulfs is oriented.

One must take care to note that we do not only mean to speak in general terms of the long coastlines of Europe, Africa, and America oriented in this way, but also in particular of all shores, large and small, included therein, which by their various folds and bends create exposures that face directly or obliquely toward the four cardinal points.

Comparison of the effects of the flow and ebb of the sea to those of a great river that overflows as it rises, and then withdraws.

598. To properly conceive of the manner in which the waters of the Ocean move along the shores, one can consider them when they flow, for example from the equator toward the poles, as a great river that rises and overflows on all sides; and conversely, when they ebb from the poles toward the equator, as the same river when it decreases and returns to its bed. According to the first supposition, a river that overflows due to a great abundance of water always has three different movements; one in the middle, which is the main current original: "fil de l'eau"; literally the "thread of the water," referring to the fastest part of the stream., and the two others toward its banks where it causes the flooding resulting from the increase of waters; likewise, when the Ocean flows from the equator toward the poles, these waters also have three different movements: one in the open sea called the great course original: "le grand cours"; referring to the main oceanic current., and the two others between this same course and the side shores, where they fill all the gulfs, mouths, bays, and other places; thus, it is by these latter two movements that it casts and sends everything toward its edges.

Just as it happens with rivers that have overflowed, that as they begin to decrease, the waters that had strayed from the main current to flood the surrounding countryside return to their old bed; in the same way, when the seas ebb and diminish on one side, all the waters that had detached from the great current to flow toward the coasts then ebb back toward the open sea to rejoin it and follow it toward the equator.