Three designs for movable bridges
A trussed movable bridge, an arched movable bridge, and a pontoon of boats or barrels
The sheet gathers three studies of movable bridges, each labelled 'ponte mobile'. At the top is a long trussed span; in the centre a lightly drawn arched bridge with a supporting mechanism; and below a floating bridge to be carried on boats or, alternatively, on barrels. Dense mirror-script fills the lower half of the page beyond the three short transcribed captions and remains untranscribed here.
On this page
Upper movable bridge: trussed span
The topmost drawing is captioned simply 'movable bridge'. It shows a long horizontal deck carried on a repeating triangular truss, an engineered span meant to be moved or deployed.
Central movable bridge: arched span
The central figure, again labelled 'movable bridge', is an arched bridge drawn in light lines with a wheel or drum mechanism at one end. It represents a second solution for a portable crossing.
Movable bridge of boats or barrels
The lowest drawing describes a movable bridge carried on boats, or if preferred on barrels: a pontoon crossing whose deck floats on buoyant supports. Such a bridge could be assembled quickly to span water, a task at the border of civil and military engineering.