In this system a large, toothed gear is attached so it can spin around a rod that runs through the center of the gear. Another smaller gear runs along the inside of the larger gear. One end of a long, straight bar is attached to one point of the smaller gear; the other end of the bar is attached to the beam of the engine. As the piston moves up and down, it moves the bar up and down. When the bar moves, it moves the smaller gear along the teeth of the larger gear. This causes the larger gear to move in a circle.
