beneath the corresponding counterpoise by a chain of the same weight,
called a compensating chain.

The pulleys, B and C, that support the suspension chains have
projections in their channels which engage with the links and thus
prevent the chains from slipping. They are mounted at the extremity of
four latticed girders that likewise carry girder pulleys, D. The pulleys
that are situated at the side of the bridge are provided laterally
with a conical toothing which gears with a pinion connected with the
maneuvering apparatus.

The two pinions of the same side of the bridge are keyed to a
longitudinal shaft which is set in motion at one point of its length by
a system of gearings. The winch upon which is exerted the stress that
is to effect the lifting or the descent of the bridge is fixed upon the
shaft of the pinion of the said gearing, which is also provided with a
flywheel, c. The longitudinal shafts are connected by a transverse one.
e, which renders the two motions interdependent. This transverse shaft
is provided with collars, against which bear stiff rods that give it the
aspect of an elongated spindle, and that permit it to resist twisting
stresses.

The windlasses that lift the bridge are actuated by manual power. Two
men (or even one) suffice to do the maneuvering.

This entire collection of pulleys and mechanism is established upon two
brick foot bridges between which the bridge moves. These arched bridges
offer no obstruction to navigation. Moreover, they always allow free
passage to foot passengers, whatever be the position of the bridge. They
are provided with four vertical apertures to the right of the suspension