The power of percussion; the Naviglio Grande; a beam bridge
Notes on force, motion, time and space, with a canal note and an interlaced-beam bridge
A working sheet dominated by a right-hand column of propositions on percussion, arguing that a blow's power grows with the speed, weight and shortness of time of the motion that generates it. A note at the upper right concerns the Naviglio Grande and the level of water above its sluice-mouths, and a line beside a small drawing mentions sounds that can be made in water near Sant'Angelo. At the foot are two sketches of a bridge built from interlaced beams, with a note on bending the timbers with fire and levers.
On this page
Percussion is strongest as the moving body leaves the mover
Leonardo states that percussion has its greatest power at the instant the moving body separates from the mover, and that this power is born of motion. The motion is the more powerful the more it is generated in less time over one and the same space.
Percussion as daughter of motion and weight
A short note calls percussion the daughter of motion and weight, so that the blow created by a longer motion and greater weight is the more powerful, the weight being joined to the cause of its motion. It opens a heading 'Of the causes of percussion.'
Water level above the sluices of the Naviglio Grande
If the Great Canal does not carry as much water as before, the shareholders do not receive their due, since where they once had a braccio and a half above the mouths they now have only half a braccio. Raising the water over the heightened mouths makes its surface flatter and slower.
Bridge of interlaced beams bent with fire
The note beneath the bridge sketches explains that the timbers are bent with fire and levers and left to cool in that curve, and that thicker doubled timbers are set at the springings, doubling them at every degree.