Dynamics of Nature - Cog-Wheels Lantern Mechanism

The gearwheel, which had been invented by Archimedes in the third century B.C., was well-known in Leonardo's time. Leonardo worked on improvements to a number of different types of gears designed to transmit motion and force. This combination gearwheel and lantern pinion often featured in his designs.
The lantern pinion is a series of small cylinders held between two discs. Here, the gearwheel is a disc with perpendicular pins at regular intervals around the perimeter. The device transmits motion when the lantern, turned by a crank, meshes with the pins on the gearwheel and moves the wheel around. In a second design, the gearwheel itself is turned by the crank. Similar mechanisms are used today in some clocks.