Ca. 1820 Simpson Manual Engine.  The exposed construction of this engine shows how almost all manual fire engines work.  Pistons in each of the pump's two cylinders suck water in on the pump handle's up stroke and push it out on the down stroke.  Thus water to both drafted and pumped on each stroke of the pump handles.  A pair of valves mounted between the air chamber and cylinders control the flow of water in and out of the cylinders.  Valves were made of leather and needed frequent replacement.  The easily accessed valve compartment on this engine was much better than  valve arrangements on most other engines.  The bulbous air chamber cushions the flow of water on its way to the hose, allowing it to flow in a steady stream.  Water comes into the engine either from a suction hose attached to its rear fitting or from buckets of water dumped into the tub.  While being restored, the maker's name, Simpson, and his address, Belgrave Road, in the Pimlico District of London, was found under four layers of paint and primer.  The engine probably spent its working life in London.

This Simpson Manual Engine is property of Hall of Flame and is on display at their museum in Phoenix, Arizona.