This model was submitted to the U.S. Patent Office with application for Patent no. 4800, issued October 7, 1846.
This engine is very similar to the Perry engine of 1844 (US National Museum accession number 309253). It differs in that the cylinder is water-jacketed and the hot cooling water is used to heat the fuel retort. Ignition is effected by heated platinum exposed to or separated from the explosive mixture by a valve.
The model shows a horizontal double-acting engine completely water-jacketed. Beside the cylinder is the retort for generating the vapors. Air is mixed with the vapor in a valve box above the retort, and valves operated by cams from a lay shaft admit the explosive mixture to passages leading to the cylinder. The gas is ignited by incandescent platinum, and combustion continues during about one-third of the stroke, the expansion of the products of combustion forcing the piston to the end of the stroke.
To start the engine it was necessary to heat the water about the retort to generate the vapor and to heat the igniter. When running, the engine developed sufficient heat for both purposes.
Perry designed this engine so that the water served not only to cool the cylinder but also to lubricate the piston and piston rod.
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.