The Notebooks of Leonardo Da Vinci — Complete
found in the Codex Atlanticus. Nor was it possible to include his
considerations on the regulation of rivers, the making of canals and
so forth (No._ 920, _Books_ 10, 11 _and_ 12_); but those passages in
which the structure of a canal is directly connected with notices of
particular places will be found duly inserted under section XVII
(Topographical notes). In Vol. I, No._ 5 _the text refers to
canal-making in general._
_On one point only can the collection of passages included under the
general heading of Physical Geography claim to be complete. When
comparing and sorting the materials for this work I took particular
care not to exclude or omit any text in which a geographical name
was mentioned even incidentally, since in all such researches the
chief interest, as it appeared to me, attached to the question
whether these acute observations on the various local
characteristics of mountains, rivers or seas, had been made by
Leonardo himself, and on the spot. It is self-evident that the few
general and somewhat superficial observations on the Rhine and the
Danube, on England and Flanders, must have been obtained from maps
or from some informants, and in the case of Flanders Leonardo
himself acknowledges this (see No._ 1008_). But that most of the
other and more exact observations were made, on the spot, by
Leonardo himself, may be safely assumed from their method and the
style in which he writes of them; and we should bear it in mind that
in all investigations, of whatever kind, experience is always spoken
of as the only basis on which he relies. Incidentally, as in No._
984, _he thinks it necessary to allude to the total absence of all
recorded observations._
I.
INTRODUCTION.
Schemes for the arrangement of the materials (919-928).
919.
These books contain in the beginning: Of the nature of water itself
in its motions; the others treat of the effects of its currents,
which change the world in its centre and its shape.
920.
DIVISIONS OF THE BOOK.
Book 1 of water in itself.
Book 2 of the sea.
Book 3 of subterranean rivers.
Book 4 of rivers.
Book 5 of the nature of the abyss.
Book 6 of the obstacles.
Book 7 of gravels.
Book 8 of the surface of water.
Book 9 of the things placed therein.
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 matters worn away by water.
921.
First you shall make a book treating of places occupied by fresh
waters, and the second by salt waters, and the third, how by the
disappearance of these, our parts of the world were made lighter and
in consequence more remote from the centre of the world.
922.
First write of all water, in each of its motions; then describe all
its bottoms and their various materials, always referring to the
propositions concerning the said waters; and let the order be good,
for otherwise the work will be confused.
Describe all the forms taken by water from its greatest to its
smallest wave, and their causes.
923.
Book 9, of accidental risings of water.
924.
THE ORDER OF THE BOOK.
Place at the beginning what a river can effect.
925.
A book of driving back armies by the force of a flood made by
releasing waters.
A book showing how the waters safely bring down timber cut in the
mountains.
A book of boats driven against the impetus of rivers.
A book of raising large bridges higher. Simply by the swelling of
the waters.
A book of guarding against the impetus of rivers so that towns may
not be damaged by them.
926.
A book of the ordering of rivers so as to preserve their banks.
A book of the mountains, which would stand forth and become land, if
our hemisphere were to be uncovered by the water.
A book of the earth carried down by the waters to fill up the great
abyss of the seas.
A book of the ways in which a tempest may of itself clear out filled
up sea-ports.
A book of the shores of rivers and of their permanency.
A book of how to deal with rivers, so that they may keep their
bottom scoured by their own flow near the cities they pass.
A book of how to make or to repair the foundations for bridges over
the rivers.
A book of the repairs which ought to be made in walls and banks of
rivers where the water strikes them.
A book of the formation of hills of sand or gravel at great depths
in water.
927.
Water gives the first impetus to its motion.
A book of the levelling of waters by various means,
A book of diverting rivers from places where they do mischief.
A book of guiding rivers which occupy too much ground.
A book of parting rivers into several branches and making them
fordable.
A book of the waters which with various currents pass through seas.
A book of deepening the beds of rivers by means of currents of
water.
A book of controlling rivers so that the little beginnings of
mischief, caused by them, may not increase.
A book of the various movements of waters passing through channels
of different forms.
A book of preventing small rivers from diverting the larger one into
which their waters run.
A book of the lowest level which can be found in the current of the
surface of rivers.
A book of the origin of rivers which flow from the high tops of
mountains.
A book of the various motions of waters in their rivers.
928.
[1] Of inequality in the concavity of a ship. [Footnote 1: The first
line of this passage was added subsequently, evidently as a
correction of the following line.]
[1] A book of the inequality in the curve of the sides of ships.
[1] A book of the inequality in the position of the tiller.
[1] A book of the inequality in the keel of ships.
[2] A book of various forms of apertures by which water flows out.
[3] A book of water contained in vessels with air, and of its
movements.
[4] A book of the motion of water through a syphon. [Footnote 7:
_cicognole_, see No. 966, 11, 17.]
[5] A book of the meetings and union of waters coming from different
directions.
[6] A book of the various forms of the banks through which rivers
pass.
[7] A book of the various forms of shoals formed under the sluices
of rivers.
[8] A book of the windings and meanderings of the currents of
rivers.
[9] A book of the various places whence the waters of rivers are
derived.
[10] A book of the configuration of the shores of rivers and of
their permanency.
[11] A book of the perpendicular fall of water on various objects.
[12] Abook of the course of water when it is impeded in various
places.
[12] A book of the various forms of the obstacles which impede the
course of waters.
[13] A book of the concavity and globosity formed round various
objects at the bottom.
[14] Abook of conducting navigable canals above or beneath the
rivers which intersect them.
[15] A book of the soils which absorb water in canals and of
repairing them.
[16] Abook of creating currents for rivers, which quit their beds,
[and] for rivers choked with soil.
General introduction.
929.
THE BEGINNING OF THE TREATISE ON WATER.
By the ancients man has been called the world in miniature; and
certainly this name is well bestowed, because, inasmuch as man is
composed of earth, water, air and fire, his body resembles that of
the earth; and as man has in him bones the supports and framework of
his flesh, the world has its rocks the supports of the earth; as man
has in him a pool of blood in which the lungs rise and fall in
breathing, so the body of the earth has its ocean tide which
likewise rises and falls every six hours, as if the world breathed;
as in that pool of blood veins have their origin, which ramify all
over the human body, so likewise the ocean sea fills the body of the
earth with infinite springs of water. The body of the earth lacks
sinews and this is, because the sinews are made expressely for
movements and, the world being perpetually stable, no movement takes
place, and no movement taking place, muscles are not necessary.
--But in all other points they are much alike.
I.
OF THE NATURE OF WATER.
The arrangement of Book I.
930.
THE ORDER OF THE FIRST BOOK ON WATER.
Define first what is meant by height and depth; also how the
elements are situated one inside another. Then, what is meant by
solid weight and by 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; besides
this, how it always falls, being in contact with the air but lower
than the air. And how water rises in the air by means of the heat of
the sun, and then falls again in rain; again, why water springs
forth from the tops of mountains; and if the water of any spring
higher than the ocean can pour forth water higher than the surface
of that ocean. And how all the water that returns to the ocean is
higher than the sphere of waters. And how the waters of the
equatorial seas are higher than the waters of the North, and higher
beneath the body of the sun than in any part of the equatorial
circle; for experiment shows that under the heat of a burning brand
the water near the brand boils, and the water surrounding this
ebullition always sinks with a circular eddy. And how the waters of
the North are lower than the other seas, and more so as they become
colder, until they are converted into ice.
Definitions (931. 932).
931.
OF WHAT IS WATER.
Among the four elements water is the second both in weight and in
instability.
932.
THE BEGINNING OF THE BOOK ON WATER.
Sea is the name given to that water which is wide and deep, in which
the waters have not much motion.
[Footnote: Only the beginning of this passage is here given, the
remainder consists of definitions which have no direct bearing on
the subject.]
Of the surface of the water in relation to the globe (933-936).
933.
The centres of the sphere of water are two, one universal and common
to all water, the other particular. The universal one is that which
is common to all waters not in motion, which exist in great
quantities. As canals, ditches, ponds, fountains, wells, dead
rivers, lakes, stagnant pools and seas, which, although they are at
various levels, have each in itself the limits of their superficies
equally distant from the centre of the earth, such as lakes placed
at the tops of high mountains; as the lake near Pietra Pana and the
lake of the Sybil near Norcia; and all the lakes that give rise to
great rivers, as the Ticino from Lago Maggiore, the Adda from the
lake of Como, the Mincio from the lake of Garda, the Rhine from the
lakes of Constance and of Chur, and from the lake of Lucerne, like
the Tigris which passes through Asia Minor carrying with it the
waters of three lakes, one above the other at different heights of
which the highest is Munace, the middle one Pallas, and the lowest
Triton; the Nile again flows from three very high lakes in Ethiopia.
[Footnote 5: _Pietra Pana_, a mountain near Florence. If for Norcia,
we may read Norchia, the remains of the Etruscan city near Viterbo,
there can be no doubt that by '_Lago della Sibilla_'--a name not
known elsewhere, so far as I can learn--Leonardo meant _Lago di
Vico_ (Lacus Ciminus, Aen. 7).]
934.
OF THE CENTRE OF THE OCEAN.
The centre of the sphere of waters is the true centre of the globe
of our world, which is composed of water and earth, having the shape
of a sphere. But, if you want to find the centre of the element of
the earth, this is placed at a point equidistant from the surface of
the ocean, and not equidistant from the surface of the earth; for it
is evident that this globe of earth has nowhere any perfect