RAILWAY. A road in which smooth tracks of wood, iron, stone, or other suitable materials are introduced for the purpose of obviating the friction of the wheels of the carriages to a greater extent than can be done on common roads. Railways are thus of various kinds, and they have been used for a very considerable time as a means of diminish ing the cost of transport of minerals and of heavy goods. Of late years they have been applied to the general purposes of intercommunication, in conjunction with the locomotive engiue, and the improvement in all social relations thus effected has been so great, that it has almost formed a new era in the history of our race.
As the construction of railway carriages, and of the engine power employed for moving them, are subjects intimately connected with the formation of the road itself, and indeed regulate some of its most important details, it appears desirable to discuss them at the same time as the railway itself is under consideration. It is intended, therefore, to present a brief sketch of the progress of invention in matters connected with railways ; an account of the general mode of designing and executing the works of the substructure, and of the roadway; an account of the usual modes of working a line of railway; and a few of the statistics of the railways already executed at home or abroad.
Ilistory.—in the cities of Northern Italy the practice of laying smooth tracks of hard marble in the ordinary paving of the streets, which prevails in those cities to the present day, appears to have been applied for many centuries; but the use of railways, properly speaking, cannot be traced farther back than to about the year 1680, when, in the neighbourhood of Newcastle-upon-Tyne, some roads with wooden rails were laid down (figs. 1 and 2), for tire purpose of facilitating the dom, about the beginning of this century, in which they were employed. The old Croydon railway, and the tramway laid down in transport of coals from the pits to the landing stages. For many years this imperfect system of road making continued in use without improvement, and it was not until about the year 1716 that a raised rail, protected by fiat iron on its upper surface, was introduced in those parts of the road whore the traction was the heaviest. The next improvement consisted in the substitution of the edge rail for the flat band screwed down to the wood, and the durability of these rails was further increased by the use of cast- instead of wrought-iron. The waggons which ran upon these rails were usually loaded to the extent of from two to three tons, and the traction was performed almost entirely by horses, unless, in a few cases, wherein the carriages were allowed to descend some inclined planes by the effect of gravity.
The introduction of the cast-iron edge rail appears to have taken place about the year 1767, at tho suggestion of Mr. Reynolds, the engineer of the first cast-iron bridge erected in England, in the Cole brook Dale.
The next step iu the history of railways was made by the applica tion of a cast-iron plate in a kind of form, instead of the straight cast-iron edge rail (fig. 3) ; this alteration was said to have been suggested by the manager of the Duke of Norfolk's collieries near Sheffield, in 1776, and the system itself is still retained in mining operations. The rails, in all the forms originally applied, were laid upon wooden sleepers (fig. 4); but about 1793, stone blocks were used to support the rail, and this apparently unimportant change, by render ing the first cost of an edge railway, and its subsequent repairs, less expensive than before, tended greatly to facilitate the introduction of the new system. Very shortly after the substitution of tho stone blocks for the wood sleepers, the coalowners of Northumberland and Durham Introduced the use of east-iron edge rails in short lengths, but fastened to chairs let into the stone blocks ; and in this manner they succeeded in obtaining a roadway upon which the traction was comparatively easy, at a very trifling expense (figs. 5 and 6). The rails were east in lengths of from 3 to 4 feet, and they were made in what is called the/SA-bellied form, or with their greatest depth In the middle ; a represents (fig. 5) the section of the rail in the middle, and t the section at the ends ; the latter were made with a half-lap joint, and through this joint a key was passed to fasten them to the chairs. The friction upon these edge rails was further diminished by making the tires of the wheels slightly conical. Many of the mine railways are even at tho present day made precisely in this manner; and so great .vas found to be the advantage tho cast-iron edge rails pro duced, that several roads were laid down in various parts of the king the Commercial Road, London, may indeed be referred to as illustra tions of the importance attached by our immediatepredecessors to the necessity for diminishing the coat of goods traffic, and of the earnest ness of their efforts to attain such results. Animal power was, how ever, the only one used until about 1810; so that the rapidity of inter communication could hardly have been much affected by any of the systems applied up to that period.