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

128 All About Inventions introduced between the brake pipe, brake cylinder, and the auxiliary reservoir, the inventor maintaining that if the wave of air, such as was sent through the signalling pipe and which brought the whistle into play, could be induced to operate the valve device which he embodied in the brake system, then almost instantaneous braking would be achieved. As events proved, his reasoning was strikingly sound. It must be explained that in the original Westing- house system, which was described as the “ non- automatic ” or “ straight-air ” brake, the retarding effect upon the train was produced by the driver moving a lever or valve, which allowed air to pass from the reservoir mounted upon the locomotive into the train pipe. This increased air pressure, travelling through the pipe, entered each cylinder mounted beneath the carriages successively and forced out- wards a piston mounted in the cylinder. To the outer end of the piston the brake lever was attached, with the result that as the piston moved outwards, the brake blocks were applied to the tread of the wheels. It was supposed that all the pistons of the carriage brake cylinders moved simultaneously and set the brakes according to the force exerted, and which varied, by the volume of air admitted into the train pipe. But as a result of the subsequent searching tests and trials, it was discovered that this supposition was incorrect. When the driver desired to release the brakes he moved the valve of the reservoir upon the locomotive so as to cut off all communication with the train pipe. Then he moved another valve which opened the train brake pipe to the air, thereby permitting the compressed air within