Water is the driver of nature.
Water, which is the vital humour of the terrestrial machine, moves by its own natural heat.6
Write first of all water, in each of its motions, then describe all its bottoms and their various materials, referring always to the propositions concerning the said waters; and let the order be good, as otherwise the work will be confused. Describe all the shapes that water assumes from its greatest to its smallest wave, and their causes.7
Divisions of the book
Book 1 of the nature of water
Book 2 of the sea
Book 3 of subterranean rivers
Book 4 of rivers
Book 5 of the nature of the depths
Book 6 of the obstacles
Book 7 of gravels
Book 8 of the surface of water
Book 9 of the things that move on it
Book 10 of the repairing of rivers
Book 11 of conduits
Book 12 of canals
Book 13 of machines turned by water
Book 14 of raising water
Book 15 of the things which are consumed by water.8
From the Order of the Book of Water
Whether the flow and ebb are caused by the moon or sun or are the breaking of this machine of the earth. How the flow and ebb differ in different countries.
How in the end the mountains will be levelled by the waters, seeing that they wash away the earth which covers them and uncover their rocks, which begin to crumble and subdued alike by heat and frost are being continually changed into soil. The waters wear away their bases and the mountains fall bit by bit in ruin into the rivers . . . and by reason of this ruin the waters rise in a swirling flood and form great seas.
How in violent tempests the waves throw down every light thing and suck much earth into the sea, which causes the water of the sea to be turbid over a wide space.
How loose stones at the base of wide, steep-sided valleys when they have been struck by the waves become rounded bodies, and many things do likewise when pushed or sucked into the sea by the waves.
How the waves quieten down and make long stretches of calm water within the sea without movement when two opposite winds meet.9
The Order of the First Book on Water
Define first what is meant by weight and depth; also how the elements are situated one inside another. Then what is meant by solid weight and liquid weight; but first what weight and lightness are in themselves. Then describe why water moves, and why its motion ceases; then why it becomes slower or more rapid.10
Of the four elements water is the second in weight and the second in respect of mobility. It is never at rest until it unites with the sea, where, when undisturbed by the winds, it establishes itself and remains with its surface equidistant from the centre of the world.
It readily raises itself by heat in thin vapour through the air. Cold causes it to freeze. Stagnation makes it foul. That is, heat sets it in motion, cold causes it to freeze, immobility corrupts it.
It is the expansion and humour of all vital bodies. Without it nothing retains its form. By its inflow it unites and augments bodies.
It assumes every odour, colour, and flavour and of itself it has nothing.11
Water is by its weight the second element that encompasses the earth, and that part of it which is outside its sphere will seek with rapidity to return there. And the further it is raised above the position of its element the greater the speed with which it will descend to it. Its qualities are dampness and cold. It is its nature to search always for the low-lying places when without restraint. Readily it rises up in steam and mist, and changed into cloud it falls again in rain as the minute parts of the cloud assemble and form drops. At different altitudes it assumes different forms, namely water or snow or hail. It is constantly buffeted by the movement of the air, and it attaches itself to that body on which the cold has most effect, and it takes with ease odours and flavours.12
It is not possible to describe the process of the movement of water unless one first defines what gravitation is and how it is created or dies. . . .
If the whole sea rests and supports itself upon its bed, the part of the sea rests upon the part of the bed; and as the water has weight when out of its element it should weigh down and press upon the things that rest on its bed. But there we see the contrary; for the seaweed and grass that is growing in these depths are neither bent nor crushed upon the bottom but they cleave the water readily as though they were growing within air.
So we arrive at this conclusion: that all the elements, though they are without weight in their own sphere, possess weight outside their sphere, that is, when moved away towards the sky, but not when moved towards the centre of the earth. Because if an element moves towards this centre it encounters another element heavier than itself, whose thinnest and lightest part is touching an element lighter than itself, and whose heavier part is placed near the element that is heavier than itself.13
That power shows itself greater which is impressed upon a lesser resistance. This conclusion is universal and we may apply it to the flow and ebb in order to prove that the sun or moon impresses itself more on its object, that is, on the waters, when these are less deep. Therefore the shallow, swampy waters ought to react more strongly to the cause of the flow and ebb than the great depths of the ocean.14
This wears down the high summits of the mountains. This lays bare and removes the great rocks. This drives the sea from its ancient shores, for it raises its bottom with the soil that it brings. This shatters and destroys the high banks. In this no stability can ever be discerned which its nature does not at once bring to naught. It seeks with its rivers every sloping valley where it carries off or deposits fresh soil. Therefore it may be said that there are many rivers through which all the element has passed and have returned the sea to the sea many times. And no part of the earth is so high but that the sea has been at its foundations, and no depth of the sea is so low but that the highest mountains have their bases there. And so it is now sharp and now strong, now acid and now bitter, now sweet and now thick or thin, now it is seen bringing damage or pestilence and then health or, again, poison. So one might say that it changes into as many natures as are the different places through which it passes. And as the mirror changes with the colour of its objects so this changes with the nature of the place where it passes: health-giving, harmful, laxative, astringent, sulphurous, salt, sanguine, depressed, raging, angry, red, yellow, green, black, blue, oily, thick, thin. Now it brings a conflagration, then it extinguishes; is warm and is cold; now it carries away, then it sets down, now it hollows out, then it raises up, now it tears down, then it establishes, now it fills up and then it empties, now it rises and then it deepens, now it speeds and then lies still, now it is the cause of life and then of death, now of production and then of privation, now it nourishes and then does the contrary, now it is salt and then is without savour, and now with great floods it submerges the wide valleys. With time everything changes. Now it turns to the northern parts eating away the base of its banks; now it overthrows the opposite bank on the south; now it turns to the centre of the earth consuming the bottom which supports it; now it leaps up seething and boiling towards the sky. Now it confounds its course by revolving in a circle, and now it extends on the western side and robs the husbandmen of their tilth, and then it deposits the taken soil on the eastern side. And thus at times it digs out and at times fills in, as it takes and as it deposits. Thus, without rest it is ever removing and consuming her borders. So at times it is turbulent and goes raving in fury, at times clear and tranquil it flows playfully with gentle course among fresh meadows. At times it falls from the sky in rain or snow or hail, at times forms great clouds of fine mist. At times it is moved of itself, at times by the force of others; at times it supports the things that are born by its life-giving moisture, at times shows itself fetid or full of pleasant odours. Without it nothing can exist among us. At times it is bathed in the hot eleme
nt and dissolving into vapour becomes mingled with the air, and drawn upwards by the heat it rises until it reaches the cold region and is pressed closer together by its contrary nature, and the minute particles become attached together. As when the hand under water squeezes a sponge which is well saturated so that the water therein escapes through the crevices and drives the rest from its position by its wave, so it is with the cold which the warm moisture compresses. For when reduced to a denser form the air that is pent up within it breaks by force the weakest part and hisses just as though it was coming out of bellows that are pressed down by an insupportable weight. And thus the lighter clouds which in various positions form obstacles in its course are driven away.15
Of Waves
The wave is the recoil of the stroke and it will be greater or less in proportion as the stroke is greater or less. A wave is never alone but is mingled with as many other waves as there are inequalities on the banks where the wave is produced. . . .
If you throw a stone into a pond with differently shaped shores all the waves which strike against these shores are thrown back towards the spot where the stone struck; and on meeting other waves they never intercept each other’s course . . . a wave produced in a small pond will go and return many times to the spot where it originated. . . . Only in high seas do the waves advance without recoil. In small ponds one and the same stroke gives birth to many motions of advance and recoil. The greater wave is covered with innumerable other waves which move in different directions; and these are deep or shallow according to the power that generated them. . . . Many waves turned in different directions can be created between the surface and the bottom of the same body of water at the same time . . . all the impressions caused by things striking upon the water can penetrate one another without being destroyed. One wave never penetrates another; but they only recoil from the spot where they strike.16
When the wave has been driven on to the shore by the force of the wind it forms a mound by putting its upper part at the bottom and turns back on this until it reaches the spot where it is beaten back anew by the succeeding wave which comes from below and turns it over on its back, and so overthrows the mound and beats it back again on the aforesaid shore, and so continues time after time, turning now to the shore with its upper movement and now with its lower fleeing away from it. . . . If the water of the sea returns towards the bed of the sea after the percussion made upon its shore, how can it carry the shells, molluscs, snails, and similar things raised from the bottom of the sea and leave them upon this shore? The movement of these things towards the shore commences when the percussion of the falling wave meets the reflex wave, for the things raised from the bottom often leap up in the wave that bounds towards the shore, and their solid bodies are raised in the mound which then draws them back towards the sea; and so continues the succession until the storm begins to abate, and they are left stage by stage where the greater waves had reached and deposited the booty which they carried, and the succeeding waves did not reach the same mark. There remain the things cast up by the sea.13
A wave of the sea always breaks in front of its base, and that portion of the crest will then be lower which before was highest.17
The spiral or rotary movement of every liquid is swifter in proportion as it is nearer to the centre of its revolution. This is a fact worthy of note, since movement in a wheel is so much slower as it is nearer to the centre of the revolving object. . . .18
[With a drawing showing water taking the form of hair.]
Observe the motion of the surface of the water, how it resembles that of hair, which has two movements—one depends on the weight of the hair, the other on the direction of the curls; thus the water forms whirling eddies, one part following the impetus of the chief current, and the other following the incidental motion and return flow.19
The centre of a particular sphere of water is that which is formed in the tiniest particles of dew, which is often seen in perfect roundness upon the leaves of plants where it falls; it is of such lightness that it does not flatten out on the spot where it rests, and it is almost supported by the surrounding air, so that it does not itself exert any pressure, or form any foundation; and because of this its surface is drawn towards its centre with equal force from every side; and so each part runs to meet another with equal force and they become magnets one of another, with the result that each drop necessarily becomes perfectly spherical, forming its centre in the middle, equidistant from each point of its surface; and as it is pulled equally by each part of its gravity, it always places itself in the middle between opposite parts of equal weight. But when the weight of this particle of water comes to be increased, the centre of the spherical surface immediately leaves this particular portion of water, and moves towards the common centre of the sphere of the water; and the more the weight of this drop increases the more the centre of the said curve approaches towards the centre of the world.20
If a drop of water falls into the sea when it is calm, it must of necessity follow that the whole surface of the sea is raised imperceptibly, seeing that water cannot be compressed within itself like air.21
2. WATER AND EARTH
The surface of the sphere of water does not move from its circuit round the centre of the world which it invests at an equal distance. And it would not move from this equidistance if the earth, which is the support and the vase of the water, did not rise above it, away from the centre of the world.
The earth is moved from its position by the weight of a little bird alighting upon it.
The surface of the sphere of the water is moved by a little drop of water falling into it.22
It is of necessity that there should be more water than land, and the visible portion of the sea does not show this; so that there must be a great deal of water inside the earth, besides that which rises into the lower air and which flows through rivers and springs.23
Amid all the causes of the destruction of human property, it seems to me that rivers hold the foremost place on account of their excessive and violent inundations. If anyone should wish to uphold fire against the fury of impetuous rivers, he would seem to me to be lacking in judgement, for fire remains spent and dead when fuel fails, but against the irreparable inundation caused by swollen and proud rivers no resource of human foresight can avail; for in a succession of raging and seething waves gnawing and tearing away high banks, growing turbid with the earth from ploughed fields, destroying the houses therein and uprooting the tall trees, it carries these as its prey down to the sea which is its lair, bearing along with it men, trees, animals, houses, and lands, sweeping away every dike and every kind of barrier, bearing along the light things, and devastating and destroying those of weight, creating big landslips out of small fissures, filling up with floods the low valleys, and rushing headlong with destructive and inexorable mass of waters. What a need there is of flight for whoso is near!
Oh, how many cities, how many lands, castles, villas, and houses has it consumed!
How many of the labours of wretched husbandmen have been rendered idle and profitless! How many families have been ruined and overwhelmed! What shall I say of the herds of cattle which are drowned and lost! And often issuing forth from its ancient rocky beds it washes over the tilled (fields). . . .24
(a) The Deluge and Shells
Since things are far more ancient than letters, it is not to be wondered at if in our days no record exists of how these seas covered so many countries; and if moreover such record ever existed, the wars, the conflagrations, the deluges of the waters, the changes of languages and of laws, have consumed every vestige of the past. But sufficient for us is the testimony of things produced in the salt waters and found again in the high mountains, far from the seas of today.25
In this work of yours you have first to prove that the shells at a height of a thousand braccia* were not carried there by the Deluge, because they are seen at one and the same level, and many mountains are seen to rise considerably above that level; and to inquire
whether the Deluge was caused by rain or by the swelling of the sea; and then you must show how, that neither by rain which makes the rivers swell, nor by the overflow of the sea could the shells, being heavy objects, be driven by the sea up the mountains or be carried there by the rivers contrary to the course of their waters.26
You now have to prove that the shells cannot have originated if not in salt water, almost all being of that sort; and that the shells in Lombardy are at four levels, and thus it is everywhere, having been made at various times. And they all occur in valleys that open towards the sea:27
Shells and the reason of their shape
The creature that resides within the shell constructs its dwelling with joints and seams and roofing and various other parts, just as man does in the house where he dwells; and this creature expands the house and roof gradually as its body increases, since it is attached to the sides of these shells. Therefore the brightness and smoothness of these shells on the inner side is somewhat dulled at the point where they are attached to the creature that dwells there, and its hollow is roughened, in order to receive the knitting together of the muscles by means of which the creature draws itself in when it wishes to shut itself up within its house. And if you wish to say that the shells are produced by nature in these mountains by means of the influence of the stars, in what way will you show that this influence produces in the same place shells of various sizes and varying age, and of different kinds?
Notebooks Page 6