This “Silver Dollar” oscillating steam engine was built by a machine shop owner in Huntington Beach, CA (name unknown). An oscillating cylinder steam engine is a simple arrangement that does not require valves to direct steam into and out of the cylinder. Instead of valves, the entire cylinder rocks, or oscillates, such that one or more holes in the cylinder line up with holes in a fixed port face or in the pivot mounting (trunnion).
This engine is unusual in that the flywheel is made from a bicentennial Eisenhower silver dollar. As Les noted, “With this engine you will never be broke!” The engine sits atop its own copper boiler, which is filled with water by unscrewing the cap the engine is fastened to. A wooden handle allows the engineer to hold the copper tank over a stove or flame to boil the water to make the steam to run it.