Pile-driving mechanics; the death of Ser Piero da Vinci, 1504
Why a pile's point belongs at its thick end, straight piles for river embankments, and a family memorandum
On folio 277v Leonardo works out the mechanics of driving piles: a single heavy blow does what a thousand light ones cannot, so the rammer must be heavy enough to beat the ground's resistance. A long note beside a lettered figure argues that a pile's point should be at its thick end and that piles in river embankments should be straight, likening the thickened base to how nature strengthens tall trees against the wind. Folio 272r opens with Leonardo's well-known memorandum of the death of his father, Ser Piero da Vinci, on 9 July 1504, and a short reckoning of 37 carlini spent over 47 days. Faint sketches and further untranscribed notes are present on both leaves.
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One heavy blow versus a thousand light ones
A thousand blows of one pound on the same object do not accomplish what a single blow of a thousand pounds does, even when the motions are equal; so the rammer must be heavy enough to overcome the ground's resistance and drive the pile to its intended place.
Point at the thick end, and straight piles for riverbanks
The pile's point should be at its thicker end for several reasons, and piles set in river embankments should be as straight as possible so the blow's force discharges wholly at the point; a curved pile deflects the force into its concave side. Leonardo compares the thickened base to how nature strengthens tall trees such as firs against the wind.
Death of Ser Piero da Vinci, 9 July 1504
A memorandum records that on Wednesday 9 July 1504, at the seventh hour, Ser Piero da Vinci, notary at the Palazzo del Podestà and Leonardo's father, died aged 80, leaving ten sons and two daughters.
A short reckoning of days and coin
A brief note records that 37 carlini and 1 soldo were given over 47 days.