The heyday of the steam engine was short, but steam power had an important role in the growth of American industry. Along the Ohio and Mississippi rivers, metropolitan cities like Pittsburgh, New Orleans, and Cincinnati provided manufacturing capabilities to support this newfound industry, while allowing the Midwest to change from an agricultural to an industrial powerhouse.

In Cincinnati, the Lane and Bodley Co. was the premier manufacturer of steam engines from the latter half of the 19th century through the ascension of the internal combustion engine in the early portion of the 20th century. Their Corliss-type steam engines, both stationary and portable, were considered state-of-the-art at the time, with uses in printing companies to drive the presses, cotton gins, sawmills, and even small factories.

Here we see a scale example of the Corliss-style steam engine that runs on simple air pressure. The Corliss design was invented by George Henry Corliss and has four valves for each cylinder, with steam and exhaust valves located at each end. Foreshadowing later combustion engine development, the Corliss engine offers variable valve timing.

The valve gear is one of the significant developments of Corliss’ design; the inlet valves are pulled open with an eccentric-driven pawl and damped using a dashpot, which is a damper that resists motion through viscous friction.

Engine speed is controlled by varying the cutoff of steam during the power stroke, yet the throttle remains wide-open during operation. There is a centrifugal governor that is linked to a pair of camshafts that determine the point during the piston stroke that the pawl will release and allow valve closure. Most importantly, the valvetrain design permitted engine speeds to be tightly controlled and offered better response to load changes.

It’s fascinating to watch this meticulously-built scale version of the Corliss in operation. Check it out!