Geared drums, presses and the quadrature of a lune
Gear trains and a striking mechanism, a crossbow note, geometry and a decorative cartouche
A busy sheet of mechanical studies: a column of stacked toothed drums and lantern pinions on vertical shafts, a large spur wheel meshing with a small pinion, a screw press and other assemblies, with tooth- and turn-counts for a gear train (pinion 8 teeth, screw 30 turns, prime mover 60 teeth) evidently for a striking mechanism. In the upper margin are small geometrical figures giving the quadrature of a lune and of a curved triangle, and beside them a note comparing how far a short and a long crossbow throw their bolts. Blocks of arithmetic and, in the lower right, a finely drawn ornamental cartouche with a foliate emblem complete the sheet.
On this page
Gear train for a striking mechanism
Tooth and turn counts for a geared train: the pinion has 8 teeth, the screw 30 turns, and the wheel of the prime motion 60 teeth (or 30 teeth or pegs to strike, as for a bell). Stacked toothed drums and pinions on vertical shafts fill the left of the sheet.
Wheels turning in contrary directions
A note that all pinions turned by the teeth of one same wheel turn in the contrary direction to it, and those set opposite across the wheel's diameter behave alike.
Quadrature of a lune and a curved triangle
Small figures showing that a f c d is the quadrature of the lune m, and that a b is the quadrature of the curved triangle n.
Range of a short versus a long crossbow
A comparison of crossbows: a short crossbow shooting a bolt with half a braccio of travel sends it 200 braccia, while a long weak crossbow with a full braccio of travel sends its arrow an unknown distance.
Ornamental cartouche with foliate emblem
In the lower right corner a finely finished decorative cartouche or escutcheon is drawn, framed with scrollwork around a central foliate emblem.