But ironmakers were soon to become busier than ever before. About the middle of the nineteenth century Sir Henry Bessemer invented a new process of making steel. Steel is only iron mixed with a small amount of carbon. Ironmakers have known how to make steel--and good steel, too--for thousands of years, but before the days of Bessemer the process had always been slow and tedious, and the cost of steel had always been very great. Bessemer undertook to make steel in large quantities and at low prices. In his experiments amid showers of molten metal he often risked his life, but his perseverance and courage were rewarded. By 1858 he had invented a process by which tons of molten iron could be run into a furnace and in a few minutes be converted into a fine quality of steel. This invention of Bessemer was the last great step in the history of the forge. [Illustration: From copyright stereograph by Underwood & Underwood, N. Y. FIG. 10.--GREAT STEEL RAIL PASSING THROUGH ROLLER STEEL MILL.] Now that steel could be made in great quantities and at a low cost it was put to uses never dreamed of in former times. Soon the railroad rail was made of steel (Fig. 10), bridges were made of steel, ships of war were plated with steel. Then ocean grayhounds and battleships were made of steel, still later steel freight cars and steel passenger coaches were introduced, while in our own time we see vast quantities of steel used in the building of houses. So while the invention of Bessemer marked the last step in the history of the forge it also marked the ending of the Age of Iron and the beginning of the wonderful age in which we live--the Age of Steel. FOOTNOTES: [8] J. R. Smith, "The Story of Iron and Steel," p. 3. [9] From "Five Black Arts," p. 311. [10] The old forge continued to be used by the side of the blast furnace for centuries, and of course where it was used it was still called a forge. Thus we are told that in Maryland in 1761, there were eight furnaces and ten forges. It is said that as late as twenty-five years ago in certain parts of the Appalachian regions the American mountaineer still worked the little primitive forge to make his iron. [11] It was given the name of _pig_ iron because when the molten metal ran into the impressions made for it upon the sanded floor and cooled, it assumed a shape resembling a family of little pigs. THE STEAM-ENGINE