“This instrument should be adapted so that when the hammer gives the final blow, it will touch something that will make a counterweight fall to draw the toothed sprocket of the first motion. And this is done so that if the master is not in time, an excessive blow will not ruin the work, and the wheel of the first motion will not lose time in finishing those that remain.”
This is a hammer for beating precious metals into very thin foils that can be turned into coins, medals or embossed foils. Its movements are synchronised and activated by weights: with each beat of the hammer the metal strip is pushed forward to receive the next strike. Leonardo also thinks about the simultaneous movement of more than one hammer by using a single energy source.
The model is based on the drawing:
- Codex Atlanticus f. 29 r. (1493)
Milano, Biblioteca Ambrosiana