UNPUBLISHED LEAVES OF LEONARDO DA VINCI

(Royal Library of Windsor Castle)

CIVIL, MILITARY, AND NAVAL ARCHITECTURE

The "Recto" refers to the front side of a manuscript leaf, as opposed to the "Verso" or back side.

On the Foundations of Buildings

The earth that is most suitable for supporting the weight of a great structure is that which is composed of tufa original: "tufo"; a type of porous rock formed from volcanic ash, common in Italian architecture or of very hard and compact gravel. If one must build upon sandy soil, it is necessary to dig until one finds the solid bed of the earth, or to use piles original: "pali"; wooden stakes driven into the ground to provide a stable foundation in soft soil made of oak or alder, driven deep and close together.

Water is the enemy of foundations

One must observe with great care the movement of the waters in the vicinity of the building. For if a stream or a hidden vein of water should pass beneath the foundations, it will, over time, carry away the finer parts of the earth, leaving the structure to lean or to crack.

The thickness of the wall at its base should be determined by the height it must reach and the weight of the roof it must sustain. See the rule of the tenth part Leonardo often referenced the Vitruvian principle that the thickness of a foundation should be greater than the wall above it, often suggesting the foundation be one-tenth wider than the wall it supports.

Observations on the Flow of Rivers

When a river strikes the bank, it does not remain there, but rebounds like a ball and strikes the opposite bank with equal force.

original: "the water that strikes the bank" (l'acqua che percuote la ripa)

The water that falls from a height into a basin...