MECHANICS AND USEFUL AETS. 53 



of the trains were not allowed to pull up from the first instant the distance 

 or semaphor signal caught their eye, but at an arbitrary given signal, indi- 

 cated at a moment when they might not be expecting it. 



Four trips were made between the junction of the two lines. The first was 

 a South Eastern train. It started, and, when traveling at the rate of 53 

 miles an hour, Capt. Tyler gave the signal to stop, and the train was brought 

 to a stand at a distance of 2,077 yards from the point where the signal was 

 given, and that simply by the driver shutting off his steam and the guard ap- 

 plying the two breaks attached to his van, without the engine having been 

 reversed. The second experiment was with a Brighton train. The last mile 

 was run hi 66^- seconds, or at the rate of about 54 miles an hour, and the 

 train was pulled up hi 1,832 yards after being signaled to stop, by shutting 

 off the steam, applying two breaks, and without reversing the engine, or in 

 less space by 245 yards than the preceding train. The third trial was con- 

 ducted with a South Eastern train, and the object of it was to ascertain in 

 what distance it could be stopped by the application of the same means, and 

 added to them, the immediate reversal of the engine after the signal to stop. 

 The result was, that the tram, while going a mile in 66 seconds, was brought 

 up at the distance of 1,790 yards, or in two minutes; but seven seconds were 

 lost in the application of the breaks by the driver not sounding his whistle 

 until after he had reversed his engine. The fourth and last experiment was 

 with a Brighton tram, and, by arrangement, every available means was em- 

 ployed to stop on being signalled namely, reversing the engine, shutting off 

 the steam, applying the brakes, and causing the engine to scatter sand along 

 the rails. The effect of all this was, that the tram, while traveling at the 

 rate of a mile in 63 seconds, was pulled up in a minute and a half after the 

 signal, and hi the distance of 1,389 yards; thus showing that the application 

 of the sand has a most important influence to stop trains in an emergency. 



RAILROAD IMPROVEMENTS. 



Since the Count de Pambour, whose careful practical experiments and 

 thorough mathematical analysis are yet unrivaled in any treatises on steam 

 engineering, descanted in glowing style upon the performances of the locomo- 

 tive engine, this great agent of civilization has far surpassed the imaginations 

 of that accomplished engineer. The "imposing spectacle" of moving on the 

 straight, level lines of the Liverpool and Manchester and the Stockton and 

 Darlington Eailway "40 or 50 loaded carriages, each weighing more than 

 10,000 pounds," is now immensely exceeded in daily practice on all the long 

 roads in our country. Mountain grades are now surmounted on the lines of 

 the Pennsylvania Central and of the Baltimore and Ohio Roads by the simple 

 adhesion of the wheels, while but a few years since ropes and fixed engines 

 were considered necessary even for hauling on levels. The empty freight car 

 now weighs 10,000 pounds, and its load some 20,000 more. The ten-wheel 

 engines of the Reading Railroad thunders steadily up grades of 21 feet per 

 mile, with loads hi coal alone of 500 tons each, and the seven-feet drivers on 

 the Hudson River Road whirl passengers from New York City to the Albany 



