Wheeled bombard carriage with a screw-lowered axle-beam
Spoked gear-wheels, a screw that drops the axle through the gun's bore, and tiller-balance notes
The sheet is crowded with mechanical studies for a large gun: spoked wheels, winches, and a bombard whose axle-beam (subbio) passes through the bore of the barrel. A screw lowers this beam so that the weight of the carriage can be set down on the ground, and a removable segment of the wheel gives room for the beam to descend. Marginal notes label three members that raise the tiller, support the tiller, and form the balance, while a compass-drawn rosette at the upper right belongs to the sheet's geometrical study of doubling a surface. Further mechanical detail is drawn but not transcribed.
On this page
Axle-beam running through the bombard's bore
The winding-beam of the wheels is described as passing through the tube (bore) of the bombard, tying the gun barrel directly into the running gear of its carriage. Marked b-a, it can be released when the two wheels are brought into register.
Screw for lowering the wheels' axle-beam to the ground
A screw is provided by which the axle-beam of the wheels is lowered so that its weight rests on the ground. A piece of the wheel is removed to give room for the beam's descent, and if the two wheels do not meet to free the beam one is stopped while the other is turned until they register.
Members that raise, support, and balance the tiller
Three left-margin notes each identify a separate part of the mechanism: one raises the tiller, one supports the tiller, and one forms the balance (bilico). They read as labels for the carriage's steering and equilibrium members.
Compass-drawn rosette (doubling a surface)
At the upper right a small circle drawn with a compass encloses a symmetrical multi-armed star figure. The sheet is classified under the geometry of doubling a surface, and this rosette is the graphic trace of that construction.