This model was submitted to the U.S. Patent Office with the application for the patent issued to William A. Lighthall, of Albany, New York, October 23, 1849, no. 6811.
The model shows a combination of a horizontal cylinder with a vertical beam to which the engine’s force is applied between the fulcrum and the connecting rod to the engine crank. It permits locating the propelling machinery of a side-wheel steamboat low within the hull.
The model is a panel representing a horizontal cylinder with piston rod connecting to a short beam pivoted at a point below the level of the cylinder. From a short distance above the point at which the piston force is applied to the beam a long connecting rod connects to the crank on the engine shaft located above the cylinder and at the middle of its length. The location of the condenser below the cylinder and the location of the air pump and the manner of operating it are shown by the model.
This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.