Mechanisms for beating gold leaf
Hammers, a toothed wheel and pinion for making gold for painters
This sheet gathers mechanisms for beating gold into leaf, drawn in ink with a hammer sketched in red chalk at the centre. Marginal notes name the parts — hammers, a toothed wheel and pinion, a spiral-spring device — and record that one apparatus 'yields gold for painters.' A note at the foot gives the size and weight of the spreading hammer and observes that a square hammer-face spreads the gold in both width and length. Further short annotations run along the left edge that the bundle does not fully transcribe.
On this page
Mechanized hammers for making gold leaf
The notes specify the tooling for beating gold: every hammer requires one of these devices, 'for making bezants.' A related mechanism, captioned beside the toothed wheel and pinion, is said to 'yield gold for painters,' that is, gold leaf.
Dimensions of the spreading hammer
The spreading hammer is to be a quarter braccio wide and an ounce thick and to weigh 20 pounds. Leonardo adds that if the hammer's face is made square, the gold will grow both in width and in length.
Spiral spring, toothed wheel and pinion
At the upper right a coiled spiral spring drives a shaft carrying a toothed wheel and pinion; a second toothed wheel appears at centre-right. These transmit power to the row of hammers laid out across the sheet.