Where structures are to be built, the amount and delicacy of detail requisite in their design and execution can hardly be described. Final pressures upon foundations must be ascertained and provided for. Accurate calculations of strains and stresses, involving the application of difficult processes and mechanical theories, must be made. The adjustment of every part must be secured with reference to its future duty. Strength and safety must be assured and economy not forgotten. Every contingency must, if possible, be anticipated, while the emergencies which arise during every great construction demand constant watchfulness and prompt and accurate decision.
The financial success of the largest enterprises rests upon such practical application of theory and experience. Even more weighty still is the fact that the safety of thousands of human lives depends daily upon the permanency and stability of railway structures. Such are some of the deep responsibilities which are involved in the active work of the Civil Engineer.
FOOTNOTE:
[8] [8] Reference is made to the substitution of locks in the Panama Canal for the original project of a canal at the sea-level.
[AMERICAN LOCOMOTIVES AND CARS.]
By M. N. FORNEY.
The Baltimore and Ohio Railroad in 1830—Evolution of the Car from the Conestoga Wagon—Horatio Allen's Trial Trip—The First Locomotive used in the United States—Peter Cooper's Race with a Gray Horse—The "De Witt Clinton," "Planet," and other Early Types of Locomotives—Equalizing Levers—How Steam is Made and Controlled—The Boiler, Cylinder, Injector, and Valve Gear—Regulation of the Capacity of a Locomotive to Draw—Increase in the Number of Driving Wheels—Modern Types of Locomotives—Variation in the Rate of Speed—The Appliances by which an Engine is Governed—Round-houses and Shops—Development of American Cars—An Illustration from Peter Parley—The Survival of Stage Coach Bodies—Adoption of the Rectangular Shape—The Origin of Eight-wheeled Cars—Improvement in Car Coupling—A Uniform Type Recommended—The Making of Wheels—Relative Merits of Cast and Wrought Iron, and Steel—The Allen Paper Wheel—Types of Cars, with Size, Weight, and Price—The Car-Builder's Dictionary—Statistical.
