In 1760, wooden railroads were in pretty general use to facilitate mining operations. Tram-roads, with rails of cast iron, first introduced at the Colebrookdale Works, at the instance of Mr. Reynolds in 1767; at the Sheffield colliery in 1776. Stone props for the support of the rails substituted for timber in 1797, at Newcastle-upon-Tyne. Edge rails were brought into use by Mr. Jessop in 1789, at Loughborough. Malleable iron edge rails adopted at Newcastle in 1805, and at Tinsdale Fell in 1808. The improved malleable edge rail now in use was invented by Mr. Birkinsaw in 1820. A locomotive engine propelled by steam was employed for the first time on the Merthyr-Tydvil Railroad in Wales in 1804. Blenkinsop’s locomotive engine, which operated by means of cog-wheels and rack rails, was invented and applied on the Leeds Railroad in 1811. But the locomotive engine that has obtained the greatest reputation and been most generally adopted was that invented by Mr. George Stevenson in 1814. This engine has undergone a variety of improvements up to 1829, and was deemed at that period more efficient than any of its predecessors. _RAILROADS IN THE UNITED STATES._ (Abstract of the Seventh Census.) In no other particular can the prosperity of a country be more strikingly manifested than by the perfection of its roads and other means of internal communication. The system of railroads, canals, turnpikes, post-routes, river navigation, and telegraphs possessed by the United States presents an indication of its advancement in power and civilization more wonderful than any other feature of its progress. In truth, our country in this respect occupies the first place among the nations of the world. From returns received at this office in reply to special circulars, and other sources of information, it is ascertained that there were, at the commencement of the year 1852, 10,814 miles of railroads completed and in use, and that 10,898 miles were then in course of construction, with a prospect of being speedily brought into use. While the whole of these 10,898 miles will, beyond reasonable doubt, have been finished within five years, such is the activity with which projects for works of this character are brought forward and carried into effect, that it is not extravagant to assume that there will be completed within the limits of the United States before the year 1860 at least 35,000 miles of railroads.