This model of an obelisk-raising machine is, in fact, a combination of simple machines: a screw, an endless screw, and gears.

The apparatus rests on an octagonal wood pillar. A wooden superstructure is supported by three columns in the neoclassical style. A handle rotates an endless screw that drives a cogwheel. The latter, in turn, moves three other cogwheels mounted on vertical screws each housed in a wooden prism. The simultaneous motion of the screws raises the prisms, which slide through the superstructure. In so doing, they raise a base carrying a marble obelisk. Provenance: Lorraine collections.