at all familiar with the general subject that the particular topic is treated in every instance by an expert, entitled as such to speak with authority. THE BUILDING OF A RAILWAY. BY THOMAS CURTIS CLARKE. Roman Tramways of Stone--First Use of Iron Rails--The Modern Railway created by Stephenson's "Rocket" in 1830--Early American Locomotives--Key to the Evolution of the American Railway--Invention of the Swivelling Truck, Equalizing Beams, and the Switchback--Locating a Road--Work of the Surveying Party--Making the Road-bed--How Tunnels are Avoided--More than Three Thousand Bridges in the United States--Old Wooden Structures--The Howe Truss--The Use of Iron--Viaducts of Steel--The American System of Laying Bridge Foundations under Water--Origin of the Cantilever--Laying the Track--How it is Kept in Repair--Premiums for Section Bosses--Number of Railway Employees in the United States--Rapid Railway Construction--Radical Changes which the Railway will Effect. The world of to-day differs from that of Napoleon Bonaparte more than his world differed from that of Julius Cæsar; and this change has chiefly been made by railways. Railways have been known since the days of the Romans. Their tracks were made of two lines of cut stones. Iron rails took their place about one hundred and fifty years ago, when the use of that metal became extended. These roads were called tram-roads, and were used to carry coal from the mines to the places of shipment. They were few in number and attracted little attention. The modern railway was created by the Stephensons in 1830, when they built the locomotive "Rocket." The development of the railway since is due to the development of the locomotive. Civil engineering has done much, but mechanical engineering has done more. The invention of the steam-engine by James Watt, in 1773, attracted the attention of advanced thinkers to a possible steam locomotive. Erasmus Darwin, in a poem published in 1781, made this remarkable prediction: "Soon shall thy arm, unconquered steam! afar Drag the slow barge, or drive the rapid car." [Illustration: First Locomotive.] The first locomotive of which we have any certain record was invented, and put in operation on a model circular railway in London, in 1804, by Richard Trevithick, an erratic genius, who invented many things but perfected few. His locomotive could not make steam, and therefore could neither go fast nor draw a heavy load. This was the fault of all its successors, until the competitive trial of locomotives on the Liverpool and Manchester Railway, in 1829. The Stephensons, father and son, had invented the steam blast, which, by constantly blowing the fire, enabled the "Rocket," with its tubular boiler, to make steam enough to draw ten passenger cars, at the rate of thirty-five miles an hour.