The Crossbow: When the Arrow Leaves the Cord
The driving force is spent before release; with three kinds of bank for falling water
Continuing On motion, Leonardo reasons about a crossbow: the cord moves far faster near the start of its travel than near the end, so the arrow has already parted from the cord by the time the driving force weakens. The knock of the bow's arms against the retaining cord therefore happens after the arrow has left and adds nothing to its flight. A small crossbow is drawn at the upper right. A separate note and sketch at the lower right show three kinds of bank or sill from which water departs and then falls to a lower level.
On this page
The bowstring's force is spent before the arrow leaves
The motion made by the cord is much faster near the beginning than near the end, so the arrow — following the nature of the greater motion of the force that drives it — is already parted from the cord when that force diminishes. The percussion the crossbow's arms make against the retaining cord occurs after the arrow has departed, and therefore does not add to its motion.
Crossbow sketched in the upper margin
A small crossbow is drawn at the top right of the sheet, illustrating the discussion of how the bow's arms drive the cord and release the arrow.
Three kinds of bank for falling water
A separate note with a sketch shows three modes of bank or sill from which water departs and then falls downward to a lower level.