An engine having a rotary member and a linear member includes a first axis about which the rotary member rotates and a second axis coupling the rotary member to an offset rotary element. The linear member is coupled to the offset rotary element by a first coupling fixed in position relative to the linear member and a second coupling that moves within a space in the linear member. The linear member moves back and forth in lateral fashion from a first position to a second position. The lateral movement of the linear member causes continuous rotational movement of the rotary member in one direction.