All About Inventions and Discoveries
The Romance of modern scientific and mechanical Achievements

136 All About Inventions represent finality. Scarcely had it been adopted upon all the American railways as by law ordained, when new conditions arose and had to be met. Train speeds were increasing, the length and weight of trains were growing, while more frequent services were being brought into operation. These factors demanded that the brake should have still greater stopping power, especially in cases of emergency ; and the fulfilment of these requirements brought about what is known as the “ high-speed ” brake, in which the features of the former brake are preserved, together with the capacity to act equally reliably and satisfactorily under the highest speed conditions. The feature which brought about this success was the embodiment of another valve, known as the high-speed reducing valve, the characteristic of which is the limitation of the braking effort to the necessities of safe and neces- sary operation under service conditions, coupled with the ability to increase this pressure considerably to make sudden emergency stops. But even this improvement did not offer full pro- vision for all phases and developments in railway operation. The next step was the evolution of what is described as the “ ET locomotive ” brake, which indicates an automatic air-brake for the engine and tender of the locomotive respectively, in addition to the train brake, of which it is independent. Up to this time the application of the brake to the loco- motive had been designedly ignored, for the reason that it was really considered unnecessary and might contribute to greater wear and tear, and consequently maintenance expenses. But the “ ET locomotive ” brake fulfils its peculiar function in the safe and