Image description for Plate XIX, fig. 3.—Crane Mechanism.

A large wooden wheel has its toothed rim mostly towards us, turned slightly to show spokes on the left. It’s on an axle fastened to an imagined wall. A rope is wound tightly to the axle and he end of it goes upwards out of the picture.

The teeth of the large wheel connect to a smaller wheel beneath it, and that’s on an axle with two wooden handles so it can be turned.

There’s another small wooden wheel on the lower axle, near one of the handles; it’s toothed, so that a latch (not shown) could be used to top it rotating and hence stop the rope from turning, keeping the crane’s load in position.

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