A thousand blows of one pound upon a single object do not perform the same task as a single blow of a thousand pounds, even though the motions of each striker are equal among themselves. Therefore you who drive piles with the timber frame, use a striker of such weight that it is sufficient to overcome the resistance of the medium that will not let the pile penetrate to the intended place.

It is far more useful to make the point on the thicker part of the pile than on the thinner part, for several reasons. The first is that you then do not have, along the sides of the whole pile, to form a wedge with which you must open the ground that resists the pile's penetration. The second is that the pile is more buffeted by the waters in its lower part than in its upper part; so that, the piles touching one another by force of the blow, the water cannot easily enter between them and draw out the sand and gravel, as one sees happen in the gaps of those that have the point below and touch above in the air, where they are beaten by no power other than the wind. The third is that, when they are laid bare from the middle upward, they are far more easily shaken or wagged by the percussion of the waters than if they had their thickness below, as nature has created them to resist the great onsets of the winds; for that part of the tree which is more remote from the power that strikes it is the more injured by that percussion, because it has the greater leverage; whence in this case nature has provided by thickening them in that part where they can most be injured, and above all in trees that grow to a great height, such as firs and the like. The piles that are set in the banks and defenses of rivers must be as straight as possible, for two reasons. The first is that, the power of the percussion penetrating through their whole length, when the pile is straight, that power discharges itself entirely upon the place where its point rests. That support gives way to the pile's penetration, if it be more powerful than the support. But if such a pile be in some part curved, then the power of the percussion, which immediately penetrates and descends along the length of the pile, meets its curvature and thrusts it into the side of the concavity that receives it; whence a great part of...

On the 9th of July 1504, on a Wednesday at the seventh hour, died ser Piero da Vinci, notary at the palace of the podestà, my father, at the seventh hour; he was 80 years of age, and left ten male children and two females.

37 carlini, 1 soldo he has given in 47 days.