Machines, balances and military-hydraulic devices
Geared frames, screws and lifting gear with two weighted balances and notes on firing and river defences
A densely worked sheet of mechanical studies drawn in pen with a red-chalk framework at the left. Across the page are geared frames, worm-screws, cranks, cylindrical bodies, a pair of dividers and various lifting and hoisting members. Interspersed notes describe two weighted balances, a scheme to fire a passavolante (light cannon) from beneath the water by wheel-motion and to burn the feet of towers with powder, a component 'of copper', and the making of defences for cities against the force of rivers.
On this page
Weighted balance beam
A balance beam at the upper right is annotated with weights: 16 at the top, then 8 and 8, a point a bearing 8, a point b bearing 4, and 4. The figures set out how the loads are distributed about the arms. A second, lighter balance nearby is marked 12 and one-and-a-half.
Firing a passavolante underwater; burning towers
A note beside a machine drawing proposes to draw and fire a passavolante (a light cannon) beneath the water, giving it fire underwater by itself through the motion of wheels and without delay. A companion instruction says to remove the windows at the foot of towers so as to set them ablaze with powder.
River defences for cities
A short note calls for defences to be made for cities against the impetus of the rivers. It sits beside a machine sketch and belongs with the sheet's mix of hydraulic and mechanical concerns. A nearby label reads simply 'of copper', identifying a component's material.
Geared frame with worm-screw and toothed wheel
At the top a substantial A-shaped frame carries a large toothed wheel and a vertical worm-screw, evidently a hoisting or driving mechanism. To its right are further geared bars and a slender balance arm. The drawing is the most finished passage on the sheet.
Dividers, cranks and lifting gear
The lower and right portions carry a large pair of dividers or compasses, cranked shafts, screw jacks and clustered gearing. A red-chalk skeletal frame at the left underlies the pen studies. Together they read as trials of transmission and lifting devices.