The second method utilizes great steam hammers weighing 125 tons, and striking Titanic blows upon the yielding metal. The most modern method, however, is by the hydraulic press forge, now used in the shops of the Bethlehem steel works in the production of Harveyized armor plate. In Fig. 257 is seen the great 14,000-ton hydraulic press-forge squeezing into shape a port armor plate for the battleship “Alabama.” After leaving the forge, the plate is trimmed to shape by the savage bite of a rotary saw and planer, seen in Figs. 258 and 259, whose insatiable appetites tear off the steel like famished fiends. The plate is then taken to be Harveyized by cementation, hardening, and tempering, as seen in Figs. 260, 261, and 262. The 125-ton mass of metal representing the plate in the rough, and weighing more than a locomotive, is thus handled and brought to shape with an ease and dispatch that inspires the observer with mixed emotions of admiration and awe. _Making Horse Shoes._--Anthony’s patent, April 8, 1831; Tolles’, of October 24, 1834, and H. Burden’s, of November 23, 1835, were pioneers in horse-shoe machines. Mr. Burden took many subsequent patents, and to him more than any other inventor belongs the credit of introducing machine-made horse shoes, which greatly cheapened the cost of this homely, but useful article. Nearly 400 United States patents have been granted for horse-shoe machines. [Illustration: FIG. 258.--ROTARY SAW, CUTTING HEAVY ARMOR PLATE.] [Illustration: FIG. 259.--ROTARY PLANER, TRIMMING HEAVY ARMOR PLATE.] [Illustration: FIG. 260.--THE CEMENTATION FURNACE.] [Illustration: FIG. 261.--HARDENING THE PLATE BY JETS OF WATER.] [Illustration: FIG. 262.--OIL TEMPERING.] _Making Screws, Bolts, Nuts, Etc._--Screw-making according to modern methods began between 1800-1810 with the operations of Maudsley. Sloan, in 1851, and Harvey, in 1864, made many improvements in machines, operating upon screw blanks. The gimlet-pointed screw, which allows the screw to be turned into wood without having a hole bored for it, was an important advance in the art. It was the invention of Thomas J. Sloan, patented August 20, 1846, No. 4,704, and was twice re-issued and extended. In later years the rolling of screws, instead of cutting the threads by a chasing tool, has attained considerable importance, and provides a simpler and cheaper method of manufacture. Knowles’ United States patent of April 1, 1831, re-issued March 1, 1833, described such a process, while Rogers, in patents No. 370,354, September 20, 1887; No. 408,529, August 6, 1889; No. 430,237, June 17, 1890, and No. 434,809, August 19, 1890, added such improvement in the process as to make it practical.