HERBERT STUMM set out to see whether a long forgotten engine that originated in the United States was the first working I/C engine to be developed by building a model from a patent drawing, made from memory.

In the 1820s former army officer, Samuel Morey, from Orford, New Hampshire, developed an atmospheric internal combustion engine, since largely neglected by historians. This remarkable device burned a blend of alcohol and turpentine, mixed with air in a heated surface carburettor.

He was unable to commercialize his patent rights, and the design fell into oblivion, having no influence on subsequent developments, even though he is distinguished as the builder of the first automobile in the United States and running it on liquid fuel.

Morey held around 20 patents all together – in those days signed by the President and the Secretary of State.

Morey was practical man, not an educated engineer, and could not produce drawings. An engineer friend, named Erskine Hazard, applied on his behalf for a UK patent, where drawings were needed. Hazard made the drawings from memory, so it is not clear how accurately they show the actual engine.

Morey’s engine was designed for use in boats and cars.

The design concept is very different to what came later. On the upstroke, fresh air is sucked in via a valve at the cylinder bottom. In the last quarter of the upstroke the valve closes and fuel is drawn in from the carburettor through a small valve in the top end of the cylinder, followed by ignition.

Pressure of the hot gases reopens the bottom valve, and gas is exhausted. At zero pressure the valve shuts automatically. Meanwhile, the remaining gas has cooled down through expansion and a vacuum is formed which pulls the piston down. A 180deg offset of the second cylinder, plus flywheel inertia, keeps the engine running.

Herbert’s model is to approx 2in. scale. It includes several alterations. Ether is used as the fuel, so the carburettor need not be heated. Ignition is by a small spark plug, because flame ignition (as on the full-size engine) will not work in a small scale.

The big poppet valve at the bottom is operated by a catch mechanism, which the inlet valve and the ignition are operated by cams; all sit on the crankshaft and are adjustable.

The spark plugs work in series so that only one pair of points on a double cam is needed. A second coil or distributor is not needed.

It took some time to get the engine to run. At first fuel was the major problem. Alcohol has to be heated to around 60deg to make a combustible gas and on route to the cylinder it cooled and reverted to liquid because of the unfavourable volume/mass ratio. The upper part of the cylinder had to be pre-heated which gave another unstable condition.

To see if the engine worked, acetylene was tried. It proved that the engine would work, but nearly blew the engine to pieces!

Ether was the eventual solution to the fuel problem. It evaporates at room temperature and burns in a wide air/gas range. Spark plugs were another problem.

But in the end Herbert Stumm proved that Morey was right.

He was the inventor of the first working internal combustion engine in the world.

Herbert Stumm’s model of the remarkable Morey engine shown and briefly demonstrated at Harrogate in 2010.