This early 20th-century miniature stationary engine model features dual spoked flywheels, a precision piston assembly, and a synchronized mechanical flap valve mechanism mounted to a solid metal base. Designed to demonstrate mechanical stroke principles, turning the flywheel cranks the piston to open and close the flap valve with steady regularity. The piece exhibits surface oxidation, dust accumulation, and age-appropriate patina throughout. As noted, one axle support has separated from the frame strut and will require re-soldering or repair for proper alignment. H 3.75", W 4", D 7.5". Please see photos for condition.