La Hire's Hypocycloidal Train Mechanism

Philippe de La Hire (1640 – 1718) was a French scientist and engineer who, among other things, worked on the theory of epicycloids.

In this device, a small wheel is driven inside a circular rack twice its diameter, by means of a brocken axis b,c,d. It found a common use in various sorts of pumps, as it allowed water or any other fluid to draw through a continuous circular movement.

The caption reads in the original French: Épicycle rectiligne de Lahire.