Clock wheels and a steam device among small mechanisms
Red-chalk sketches of gears and clockwork, a head-vessel that turns water to air by fire, and sums.
The sheet is covered with rapid red-chalk sketches of small mechanisms, gears, wheels and linkages, among them a 'wheel of time' and 'wheel of the hours' that point to clockwork. Two notes describe a device in which wind and water turn into air: a head-shaped vessel filled with water and heated by fire beneath, so that it blows through the water as the water converts to air, like a hissing firebrand. Columns of figures are worked in the margins.
On this page
'Wheel of time' and 'wheel of the hours' (clockwork)
A note at the upper left names a rota di tempo and a rota dell'ore, a wheel of time and a wheel of the hours, beside the small toothed wheels sketched across the sheet. Together they point to the trains of a clock.
Head-vessel turning water to air by fire
Two notes describe a head full of water set over a fire, which blows through the water as the water turns into air, wind and water converting into air as seen in a firebrand that hisses. It is drawn as a head blowing into a tube.
Many small mechanisms sketched in red chalk
Across both halves of the sheet Leonardo scatters rapid studies of gears, toothed wheels, cranks and linkages, several boxed like machine assemblies. They are laid in loosely in red chalk with no continuous text.
Marginal sums
Blocks of figures are worked in the margins and along the foot of the sheet, one column resolving to a total of 672. They accompany the mechanical sketches rather than any continuous prose.