The Notebooks of Leonardo Da Vinci (69 page)

That the shells were not carried away from the sea by the deluge,
because the waters which came from the earth although they drew the
sea towards the earth, were those which struck its depths; because
the water which goes down from the earth, has a stronger current
than that of the sea, and in consequence is more powerful, and it
enters beneath the sea water and stirs the depths and carries with
it all sorts of movable objects which are to be found in the earth,
such as the above-mentioned shells and other similar things. And in
proportion as the water which comes from the land is muddier than
sea water it is stronger and heavier than this; therefore I see no
way of getting the said shells so far in land, unless they had been
born there. If you were to tell me that the river Loire [Footnote:
Leonardo has written Era instead of Loera or Loira—perhaps under
the mistaken idea that
Lo
was an article.],which traverses France
covers when the sea rises more than eighty miles of country, because
it is a district of vast plains, and the sea rises about 20 braccia,
and shells are found in this plain at the distance of 80 miles from
the sea; here I answer that the flow and ebb in our Mediterranean
Sea does not vary so much; for at Genoa it does not rise at all, and
at Venice but little, and very little in Africa; and where it varies
little it covers but little of the country.

The course of the water of a river always rises higher in a place
where the current is impeded; it behaves as it does where it is
reduced in width to pass under the arches of a bridge.

Further researches (989-991).

989.

I say that the deluge could not carry objects, native to the sea, up
to the mountains, unless the sea had already increased so as to
create inundations as high up as those places; and this increase
could not have occurred because it would cause a vacuum; and if you
were to say that the air would rush in there, we have already
concluded that what is heavy cannot remain above what is light,
whence of necessity we must conclude that this deluge was caused by
rain water, so that all these waters ran to the sea, and the sea did
not run up the mountains; and as they ran to the sea, they thrust
the shells from the shore of the sea and did not draw them to wards
themselves. And if you were then to say that the sea, raised by the
rain water, had carried these shells to such a height, we have
already said that things heavier than water cannot rise upon it, but
remain at the bottom of it, and do not move unless by the impact of
the waves. And if you were to say that the waves had carried them to
such high spots, we have proved that the waves in a great depth move
in a contrary direction at the bottom to the motion at the top, and
this is shown by the turbidity of the sea from the earth washed down
near its shores. Anything which is lighter than the water moves with
the waves, and is left on the highest level of the highest margin of
the waves. Anything which is heavier than the water moves, suspended
in it, between the surface and the bottom; and from these two
conclusions, which will be amply proved in their place, we infer
that the waves of the surface cannot convey shells, since they are
heavier than water.

If the deluge had to carry shells three hundred and four hundred
miles from the sea, it would have carried them mixed with various
other natural objects heaped together; and we see at such distances
oysters all together, and sea-snails, and cuttlefish, and all the
other shells which congregate together, all to be found together and
dead; and the solitary shells are found wide apart from each other,
as we may see them on sea-shores every day. And if we find oysters
of very large shells joined together and among them very many which
still have the covering attached, indicating that they were left
here by the sea, and still living when the strait of Gibraltar was
cut through; there are to be seen, in the mountains of Parma and
Piacenza, a multitude of shells and corals, full of holes, and still
sticking to the rocks there. When I was making the great horse for
Milan, a large sack full was brought to me in my workshop by certain
peasants; these were found in that place and among them were many
preserved in their first freshness.

Under ground, and under the foundations of buildings, timbers are
found of wrought beams and already black. Such were found in my time
in those diggings at Castel Fiorentino. And these had been in that
deep place before the sand carried by the Arno into the sea, then
covering the plain, had heen raised to such a height; and before the
plains of Casentino had been so much lowered, by the earth being
constantly carried down from them.

[Footnote: These lines are written in the margin.]

And if you were to say that these shells were created, and were
continually being created in such places by the nature of the spot,
and of the heavens which might have some influence there, such an
opinion cannot exist in a brain of much reason; because here are the
years of their growth, numbered on their shells, and there are large
and small ones to be seen which could not have grown without food,
and could not have fed without motion—and here they could not move
[Footnote: These lines are written in the margin.]

990.

That in the drifts, among one and another, there are still to be
found the traces of the worms which crawled upon them when they were
not yet dry. And all marine clays still contain shells, and the
shells are petrified together with the clay. From their firmness and
unity some persons will have it that these animals were carried up
to places remote from the sea by the deluge. Another sect of
ignorant persons declare that Nature or Heaven created them in these
places by celestial influences, as if in these places we did not
also find the bones of fishes which have taken a long time to grow;
and as if, we could not count, in the shells of cockles and snails,
the years and months of their life, as we do in the horns of bulls
and oxen, and in the branches of plants that have never been cut in
any part. Besides, having proved by these signs the length of their
lives, it is evident, and it must be admitted, that these animals
could not live without moving to fetch their food; and we find in
them no instrument for penetrating the earth or the rock where we
find them enclosed. But how could we find in a large snail shell the
fragments and portions of many other sorts of shells, of various
sorts, if they had not been thrown there, when dead, by the waves of
the sea like the other light objects which it throws on the earth?
Why do we find so many fragments and whole shells between layer and
layer of stone, if this had not formerly been covered on the shore
by a layer of earth thrown up by the sea, and which was afterwards
petrified? And if the deluge before mentioned had carried them to
these parts of the sea, you might find these shells at the boundary
of one drift but not at the boundary between many drifts. We must
also account for the winters of the years during which the sea
multiplied the drifts of sand and mud brought down by the
neighbouring rivers, by washing down the shores; and if you chose to
say that there were several deluges to produce these rifts and the
shells among them, you would also have to affirm that such a deluge
took place every year. Again, among the fragments of these shells,
it must be presumed that in those places there were sea coasts,
where all the shells were thrown up, broken, and divided, and never
in pairs, since they are found alive in the sea, with two valves,
each serving as a lid to the other; and in the drifts of rivers and
on the shores of the sea they are found in fragments. And within the
limits of the separate strata of rocks they are found, few in number
and in pairs like those which were left by the sea, buried alive in
the mud, which subsequently dried up and, in time, was petrified.

991.

And if you choose to say that it was the deluge which carried these
shells away from the sea for hundreds of miles, this cannot have
happened, since that deluge was caused by rain; because rain
naturally forces the rivers to rush towards the sea with all the
things they carry with them, and not to bear the dead things of the
sea shores to the mountains. And if you choose to say that the
deluge afterwards rose with its waters above the mountains, the
movement of the sea must have been so sluggish in its rise against
the currents of the rivers, that it could not have carried, floating
upon it, things heavier than itself; and even if it had supported
them, in its receding it would have left them strewn about, in
various spots. But how are we to account for the corals which are
found every day towards Monte Ferrato in Lombardy, with the holes of
the worms in them, sticking to rocks left uncovered by the currents
of rivers? These rocks are all covered with stocks and families of
oysters, which as we know, never move, but always remain with one of
their halves stuck to a rock, and the other they open to feed
themselves on the animalcules that swim in the water, which, hoping
to find good feeding ground, become the food of these shells. We do
not find that the sand mixed with seaweed has been petrified,
because the weed which was mingled with it has shrunk away, and this
the Po shows us every day in the debris of its banks.

Other problems (992-994).

992.

Why do we find the bones of great fishes and oysters and corals and
various other shells and sea-snails on the high summits of mountains
by the sea, just as we find them in low seas?

993.

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 seas.

994.

>From the two lines of shells we are forced to say that the earth
indignantly submerged under the sea and so the first layer was made;
and then the deluge made the second.

[Footnote: This note is in the early writing of about 1470—1480. On
the same sheet are the passages No. 1217 and 1219. Compare also No.
1339. All the foregoing chapters are from Manuscripts of about 1510.
This explains the want of connection and the contradiction between
this and the foregoing texts.]

Constituents of the atmosphere.

995.

That the brightness of the air is occasioned by the water which has
dissolved itself in it into imperceptible molecules. These, being
lighted by the sun from the opposite side, reflect the brightness
which is visible in the air; and the azure which is seen in it is
caused by the darkness that is hidden beyond the air. [Footnote:
Compare Vol. I, No. 300.]

On the motion of air (996—999).

996.

That the return eddies of wind at the mouth of certain valleys
strike upon the waters and scoop them out in a great hollow, whirl
the water into the air in the form of a column, and of the colour of
a cloud. And I saw this thing happen on a sand bank in the Arno,
where the sand was hollowed out to a greater depth than the stature
of a man; and with it the gravel was whirled round and flung about
for a great space; it appeared in the air in the form of a great
bell-tower; and the top spread like the branches of a pine tree, and
then it bent at the contact of the direct wind, which passed over
from the mountains.

997.

The element of fire acts upon a wave of air in the same way as the
air does on water, or as water does on a mass of sand —that is
earth; and their motions are in the same proportions as those of the
motors acting upon them.

998.

I ask whether the true motion of the clouds can be known by the
motion of their shadows; and in like manner of the motion of the
sun.

999.

To know better the direction of the winds. [Footnote: In connection
with this text I may here mention a hygrometer, drawn and probably
invented by Leonardo. A facsimile of this is given in Vol. I, p. 297
with the note:
'Modi di pesare l'arie eddi sapere quando s'a
arrompere il tepo'
(Mode of weighing the air and of knowing when
the weather will change); by the sponge
"Spugnea"
is written.]

The globe an organism.

1000.

Nothing originates in a spot where there is no sentient, vegetable
and rational life; feathers grow upon birds and are changed every
year; hairs grow upon animals and are changed every year, excepting
some parts, like the hairs of the beard in lions, cats and their
like. The grass grows in the fields, and the leaves on the trees,
and every year they are, in great part, renewed. So that we might
say that the earth has a spirit of growth; that its flesh is the
soil, its bones the arrangement and connection of the rocks of which
the mountains are composed, its cartilage the tufa, and its blood
the springs of water. The pool of blood which lies round the heart
is the ocean, and its breathing, and the increase and decrease of
the blood in the pulses, is represented in the earth by the flow and
ebb of the sea; and the heat of the spirit of the world is the fire
which pervades the earth, and the seat of the vegetative soul is in
the fires, which in many parts of the earth find vent in baths and
mines of sulphur, and in volcanoes, as at Mount Aetna in Sicily, and
in many other places.

[Footnote: Compare No. 929.]

Topographical Notes.

A large part of the texts published in this section might perhaps
have found their proper place in connection with the foregoing
chapters on Physical Geography. But these observations on Physical
Geography, of whatever kind they may be, as soon as they are
localised acquire a special interest and importance and particularly
as bearing on the question whether Leonardo himself made the
observations recorded at the places mentioned or merely noted the
statements from hearsay. In a few instances he himself tells us that
he writes at second hand. In some cases again, although the style
and expressions used make it seem highly probable that he has
derived his information from others— though, as it seems to me,
these cases are not very numerous—we find, on the other hand, among
these topographical notes a great number of observations, about
which it is extremely difficult to form a decided opinion. Of what
the Master's life and travels may have been throughout his
sixty-seven years of life we know comparatively little; for a long
course of time, and particularly from about 1482 to 1486, we do not
even know with certainty that he was living in Italy. Thus, from a
biographical point of view a very great interest attaches to some of
the topographical notes, and for this reason it seemed that it would
add to their value to arrange them in a group by themselves.
Leonardo's intimate knowledge with places, some of which were
certainly remote from his native home, are of importance as
contributing to decide the still open question as to the extent of
Leonardo's travels. We shall find in these notes a confirmation of
the view, that the MSS. in which the Topographical Notes occur are
in only a very few instances such diaries as may have been in use
during a journey. These notes are mostly found in the MSS. books of
his later and quieter years, and it is certainly remarkable that
Leonardo is very reticent as to the authorities from whom he quotes
his facts and observations: For instance, as to the Straits of
Gibraltar, the Nile, the Taurus Mountains and the Tigris and
Euphrates. Is it likely that he, who declared that in all scientific
research, his own experience should be the foundation of his
statements (see XIX Philosophy No. 987—991,) should here have made
an exception to this rule without mentioning it?