1886,] NEW YORK ACADEMY OF SCIENCES. 149 



30,000, whicli, if placed in lino, would reach from New York to 

 Syracuse. The passenger, mail, express, and baggage cars 

 would each extend about the same distance. The 830,000 

 freight cars coupled together would link New York to San Fran- 

 cisco. 



To develop all these railways and build the necessary docks, 

 coal chutes, elevators, warehouses, stations, and terminal facilities 

 in the great cities, to cross the rivers and tunnel the mountains, 

 have absorbed over one-seventh of the estimated wealth of this 

 new and prosperous country. To manufacture all these locomo- 

 tives, cars, wheels, springs, rails, and other specialties, enormous 

 plants have been created, giving employment to thousands of 

 artisans, miners, and laborers. 



In operation the railways become great consumers of steel, 

 iron, timber, paint, upholstery, glass, special tools, coal-oil, 

 waste, etc. Armies of men are employed to run the trains, 

 handle the freight and keep up the repairs of locomotives, cars, 

 and track. 



In a trip from New York to Cliicago only a few employees 

 can be seen, yet the number required to run tlie N. Y. 0. & H. 

 E. E. E. and the L. S. & M. S. Ey., exceeds the complement of 

 tlie 25,000 soldiers of our standing army. 



The movement of so many heavy and fast trains has demanded 

 unlimited safety appliances, especially for the passenger service. 

 The old system of hand braking has given way to the Westing- 

 house Air Brake system, by which the engineer who is dashing 

 ahead at fifty miles per hour, may bring his train to rest in twice 

 its length. It is not merely a convenience, but an absolute 

 essential for present service. 



The Miller platform, drawbar, and buffer have prevented thous- 

 ands of cars from telescoping in collisions, and the consequent 

 saving of life has been immeasurable. 



Electric signals have been in use for many years on some of the 

 eastern lines; and from long experience in remedying weak points 

 are now quite successful. They are considered aids to the keen 

 human intelligence required to move safely the numerous and 

 frequent trains. 



Theoretically, it would seem an easy matter to introduce a 

 system of signals; but it is only developed by years of experience, 

 and vast outlay of time and money. The system of interlocking 

 switches and signals is extensively used at our eastern stations. 

 This places a series of switches under the control of one man. 



The greatest possible care is taken of the rolling stock; trains 

 are inspected, wheels examined, boxes oiled, and axles are only 

 allowed to run from 80 to 100,000 miles before being removed, 

 that being considered the limit of safety for passenger service. 



