Of the impressions of motion retained less in water than in air, and less in running water than in still. — The current of the small river that enters the deep directs itself toward the course of the greater current (35 M). — Of the defences of riverbanks. — Of the things carried on the surface of the water. — Of the things carried wholly within the body of the water. — Of the things moved upon the water by others (29 M). — Of the things moved upon the water by the winds. — Of finding waters in their veins. — Of bending the rivers (25 M). — Of filling the depths beneath the riverbanks. — Of reflected waves. — Of guarding against the blows of the waves on the bank. — Of the swell of the sea-shores. — How rivers fill the sea and drive it from its place (22 M). — How rivers have sawn the mountains and drained the lakes (22 M). — Of the surface percussion of waters in various hollows (23 m). — In how many ways flux and reflux may be generated among the islands of the sea and rivers. — And where the waters meet slowly and along a straighter line, there the effect is slower. — How the beds of rivers in time rise toward the surface of the water, as the Arno shows, running from Montelupo downward, where once there was sea and which formerly did not flow. — How the sphere of water rises through the water regained by the inland seas, driven out by the soil the turbid rivers leave within them (23 m). — Of the nature of the places where water leaves sand, stones and mud (21 m). — Of the various encounters of currents and the various beds they generate (21 m). — Of the varieties of the currents of waters and winds (20 m). — Of the wearing-away of mountains struck by the course of rivers (20 m).

How the course of waters that grow turbid should be of moderate obliquity, because too great an obliquity — with soil on its bed — and too steep a slope wears away the bed and the bank above collapses. Waters that do not grow turbid should have less than a moderate descent, so that it does not undermine the bank.

Of waters striking objects of double obliquity. — The difference of course and wearing between rivers that run through narrow valleys and those that spread over the great plains. — The difference of the beds of rivers with great slopes and falls compared with those running over plains with gentle, slow motion. — How the bed of water that goes and returns varies, as the wave beating the shores, compared with water going only one way. — Of the various heights of currents that meet along different lines (20 m). — Of drops and other minute operations of the waters (20 and 19 m). — Of the tenacity and attraction of the waters (18 m). — Of draining marshes by making the waters carry soil into them. — Of the lengthening and shortening of rivers (17 m). — Of the uncovering and creation of islands (17 m). — Of conducting waters under the ground; along the ground; above the ground. — Of the ruin of mountains undermined by the courses of waters (17 m). — Of the silt beneath the waters (7 m). — Of the various motions of things of various shapes and sizes. — Of the things carried by the waters. — Of the saltness of the sea and whence it arises (16 m). — How, against the natural motion of heavy things, water rises to the highest mountain-summits, departing from the lowest depths of the sea. And here it will be said: if water within water does not weigh, still less will water weigh within the earth, because water of itself does not weigh unless it lies above a body lighter than itself, and it does as the blood-vessels do in animals (16 m). — How all the veins and rivers throughout the world are joined together (16 m). — How to draw off the waters of pools lying at the level and borders of the sea. — Many rivers dry up in their long courses, and many grow over such length (16 m). — Of the causes of the various lines of currents. — Of rivers that fail in summer and of those that grow. — Of the animals that swim upon or below the water, and the rules and reason of swimming. — Of the things taken away and cast up by the sea on its shore. — Why the depths of river-mouths that pour into the sea vary so often. — Of the silting-up of sea harbours. — Of navigable canals made by hand. — Where and which waters best resist weights.

To make the percussion of water do no harm to the object. — Of conducting boats into the high mountains by water canals. — To make the sea-waves cleanse the harbours they have filled. — Of straightening or bending the courses of rivers. — Of making the courses of rivers fast or slow. — Of making river-courses low in the middle, so they be not wandering and destroyers of their valleys. — Why the waves vary in one and the same course, riverbed and quantity of water. — To make water rise by means of itself. — It does not appear possible to make mills in dead water. — Borings and hollows made in riverbeds by the whirling of waters. — Round mounds formed on riverbeds by the whirling of waters. — Of the various shapes of waves in one and the same flood. — Of making water rise by means of the motions of rivers. — Of the whirling of waters over riverbeds (14 m). — Whirlings of waters through the opposition of various objects (14 m). — Of finding veins of water. — Of the motions of waters after the percussion of their objects. — Ruin of bridges over rivers and their permanence. Of things moved by winds upon the waters. — Of the hollows the water makes in front of its objects. — Of the hollows the water makes at the side of and behind its objects. — Of the grounds raised by the waters behind their objects. — Of the division of rivers at the encounter with their objects. — Of the rejoining of rivers behind their objects. — The difference the water makes in scouring around its objects when they are covered rather than uncovered. — Of torrents and natural rivers. — Of rains. — Of the varieties of the branchings of rivers that meet together. — Of the divisions of rivers into various branches. — Of the smaller rivers that enter the greater along different lines. — Of the branches drawn off from rivers. — Of the various intersections a river makes in passing through another. — Of the bends of the banks that in time traverse the whole plain through which the river passes (13 m). — Cause of the branchings of rivers. — Cause of the unions of various rivers.

All these books are double, because each has its contrary. — Of the water of mills, of the line interrupted in its straightness before it strikes the wheel. — Of the joining of waters of various depths.

Whether the motion of water passing through a pipe of various widths varies in any part of its course or not. — Of the drop that falls and of the water continuously falling through the air. — Of the water that falls resting upon its channel. — Of the various powers water exerts issuing at various heights and sides of its reservoir. — Of the wearing of the earth that turns into water. Of the origins of rivers and their varieties. — Of levelling the waters and their due descent; it is proved where the sea has left its bed uncovered to the air. — Of the various matter left by the floods of rivers in various places (12 m). — Of the changes of riverbeds while their floods proceed. — Change of riverbeds after their floods; where the water leaves the beds of rivers and runs through other places. — Variety of effects of waters through the varieties of their furies. — Variety of effects through variety of the sizes of rivers. — Breakings of the banks of rivers that overtop their plains. — Of the flooding of countries by outpourings of water into enclosed valleys. — Of guarding against the discharges of waters brought about in lonely ambushes. — Of dividing a great river into many little branches fit to be crossed by armies. — How rivers ought to be straightened. — Whether the sphere of water has its centre concentric with the centre of the earth. — Which waves of the bank are those that do not travel with the other waves of the bank of the plains. — Causes of the bendings of straight rivers (11 m). — Of rivers that, overtopping their plains, are held in by the banks. — Of rivers and canals that are drunk up by their own beds. — Of the boilings-up of waters in their reflected motions. — Of the knowledge of the depths of turbid rivers. — Of the waves of rivers made against the course of the winds. — In how many motions water can go against its own course. — Of what kind the obliquity of water must be to give motion by itself (10 m). — In the greater depth the wind generates greater waves. — Where rivers make greater waves.