A train of nine wedges and the halving of impact force
Which wedge presses hardest when the first is struck, with the oil-press sack detail
Leonardo poses a mechanics problem: given nine wedges in a row, if the first is struck, which point will move with most force and press hardest on the object before it. He reasons that each wedge passes on only half the force it receives, so b takes one half, c one quarter, d one eighth, and the last, of least motion, presses most powerfully. A separate note describes the iron a of the oil press pouring oil through hole n over a coarse wool sack, and a marginal line records that the original was made by one Pierantonio.
On this page
Diminishing force through a series of wedges
Of nine wedges moved by striking the first, the most powerful in pressing is the one of least motion, which is the last. Wedge a loses half its force at m and half at b, so b receives half the blow, c a quarter, d an eighth, and so on successively. The point pressed against the object is where the least motion yields the greatest pressure.
Oil press with iron spout and wool sack
The iron a is a finger thick, and through the hole n it pours the oil that overflows onto the sack, passing behind and descending into the vat. The sack that holds the nuts is of coarse wool, woven like the girths of mules. It is then bound along one side by a very strong band of good ropes.
Marginal attribution note
A short line at the middle of the page records that the original was made by one Pierantonio. It stands apart from the mechanical demonstrations around it. The reading of the name is partly abbreviated.