Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

@Maxwell, I take back what I said about the pipe on top being a safety valve.  The engine was described as having a throttle valve, and I don't see any traditional valves on the engines, so perhaps Dewey put the valve inside of the boiler. Looking at this engine again, that might be a lever, not a pipe.  Perhaps it controls a sleeve over the end of the steam pipe with holes drilled in both.  Turning the valve would control the alignment of the two holes.