Steam motor cycle, 1.5 h.p., made by Heinrich and Wilhelm Hildebrand, Munich, Germany, 1889. The frame, of approximately safety-bicycle form, carries a steel tube flash boiler of the Serpollet type between the two wheels fired by small coke. The boiler could also be fired by petrol. The rear mudguard is in the form of a semi-circular tank which holds about five gallons of water. A plunger feed pump driven by a small overhung crank from the left hand side of the rear wheel, supplies water from this tank to the boiler. control of the power output was obtained by varying the amount of water injected into the boiler tubes by means of a valve which was operated by the rider through a wire control. It is powered by a single- cylinder, double-acting, slide valve engine.