Canal barriers, plank joints, and a spoked-wheel mechanism
Stop-boards to drain the ditches, the joinery of the boards, and geared wheel and rack sketches
One note describes barriers set within canals—stop-boards (storie) used to drain the ditches wherever the water threatens to overtop them—while a heading records the composition and joints of the planks from which such barriers are built. A large spoked wheel carrying a radial arm and a wedge is drawn at the top of the sheet, and a toothed rack with a roller and lever below. Further lines of Leonardo's writing, beyond the short note transcribed, run across the middle of the page.
On this page
Stop-boards to drain the canal ditches
The note describes barriers within canals: stop-boards (storie) used for drying out the ditches wherever the water would rise above them. It is a device for controlling and draining standing water in a canal system.
Spoked wheel and toothed rack
A large spoked wheel with a radial arm and a wedge is drawn at the top of the sheet, its hub and rim laid out with radiating lines. Below, a toothed rack or ramp works against a roller and lever.
Composition and joints of the planks
A heading records the composition and joints of the planks, the carpentry by which the timber barriers would be assembled. It ties the joinery directly to the canal stop-boards described alongside.