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

132 All About Inventions speed which could be attained—in 18 seconds. In the later trials—1878—which were probably the most searching which ever have been carried out, and which yielded technical data of inestimable signifi- cance, an experimental vehicle equipped therewith was stopped when travelling at 52 miles an hour in 11J seconds. In America the Pennsylvania Railway also sub- mitted the automatic system to an exacting demon- stration. A train of fifty vehicles was made up and fitted throughout with this system. It was hauled to the section running through the Allegheny Mountains, which had been the testing ground for the “ straight- air ” brake a few years before. Here every conceivable condition which was likely to be encountered in rail- way operation, including locomotive failure and break- aways, were carried out, but the brake proved equal to every emergency, and able to bring a train to, and to hold it at, a standstill even upon the steepest gradients. But it was in 1887 that the Westinghouse system was subjected to its most critical test, and in com- petition with other systems. An elaborate series of trials was inaugurated by the association of the American firms specialising in the manufacture of railway vehicles to determine the suitability of the system for goods wagons, which in the United States are far larger and heavier than those used in these islands, and on which the urgency of brakes had become only too apparent owing to the frequency of accidents to goods trains. The trains comprised fifty vehicles, and the tests were spread over a prolonged period, so as_to secure