A Stumpf Uniflow

for the electric light, Charlottenburg, 1909

Professor Stumpf’s one-way engine, built for the dynamo age: superheated steam in at the hot ends, out at the cold middle, and compound economy from a single cylinder with nothing to go wrong. It was the piston engine’s closing argument — brilliant, and too late. The turbine men bought tickets to the lectures and went home unworried.

Uniflows returned compound duty from one cylinder at dynamo speeds — the best of them near 11 lb of steam per horse-hour.

On our bed she holds a hundred and two revolutions, near three hundred horses, at a duty of a hundred and seventy millions — the cabinet’s best.

One of the cabinet’s specimens, each ready for the test bed.