The Manuscripts of Leonardo da Vinci, Vol. 2

Manuscript Facsimile

The following is a translation of Leonardo's right-to-left mirror script, preserving the original structure and word forms.

That water which shall descend one inch oncia: a historical unit of measure, roughly 1/12th of a foot per mile will have a movement of 1/4 of a braccio: an Italian cubit or "arm's length," roughly 23 inches for one beat, that is, a musical beat. Leonardo frequently used musical tempo or his own pulse as a standardized way to measure time before the invention of the pendulum clock.

That which descends 2 inches per mile will descend and have a movement of 1/2 a braccio per beat, and likewise that which descends 4 inches will move one braccio per beat.

There can be no voice original: "voce"; here meaning sound or vocalization where there is no movement or percussion of air; there can be no percussion of this air where there is no instrument; there can be no incorporeal instrument. Since this is the case, a spirit can have neither voice, nor form, nor strength; and if it should take on a body, it could not enter, penetrate, or go in where the doors are locked — 4 —

Leonardo includes a sketch of a centrally planned architectural dome with a lantern and cross, typical of his designs for "ideal" churches.

— 4 — And if anyone should say that by air gathered and compressed together, the spirit takes on bodies of various forms, and through that instrument speaks and moves with force: to this part I say that where there are no nerves and bones, no force can be operated in any movement made by imagined spirits. — Flee the precepts of those speculators whose reasonings are not confirmed by experience. This is one of Leonardo's famous aphorisms, prioritizing empirical observation over abstract philosophical or theological speculation.

Small diagram of a rectangular block.

Drawing of a mechanical mechanism featuring wheels, axles, and a vertical frame, possibly a device for lifting or measuring force.

Detail sketch of a narrow, arched vertical structure, possibly a study for a window or a niche in the building's facade.

OF MOTION AND PROPORTION

If you wish to know where, or in what part of its path, an object propelled by a violent cause meaning an external force, like a shot or a throw [acts with the most power], you shall make a mass of fresh earth and, with a crossbow, shoot an arrow into it from various distances; and where the same arrow sticks deepest, that distance is where it is strongest. Let us suppose the case that the arrow is marked for a range of 400 braccia; make the first shot at a distance of 25, then at 50, and so on, moving back 25 braccia at a time until you reach 400, shooting every 25. Thus, you will see in what part of its course the arrow is most powerful: whether at 1/3, 1/4, or 1/5 of the way. If you wish to see an experiment in proportion: if a stone is thrown 20 braccia by a small briccola: a type of medieval catapult or counterweight engine with a counterweight of ten, see if a counterweight of 20 will throw it twice as far or not. And let that which you throw be fresh earth wrapped in fresh paper—the earth so that it does not bounce after the impact, and wrapped in paper so that it does not stick to the briccola.

How to raise and place a beam through a window with ease.