1842 14 1843 12 1844 22 1845 27 1846 42 1847 39 1848 20 1849 30 1850 37 1851 50 1852 49 1853 60 1854 62 1855 47 1856 59 1857 66 1858 33 1859 70 1860 83 1861 40 1862 75 1863 96 1864 130 1865 115 1866 118 1867 127 1868 124 1869 235 1870 280 1871 331 1872 442 1873 437 1874 205 1875 130 1876 232 1877 185 1878 292 1879 398 1880 517 1881 555 1882 563 1883 557 The present capacity of the Baldwin works is one thousand locomotives a year, and they have built up to this date about fifteen thousand locomotives, or nearly one-half of all the locomotives in use in the United States. The successive steps of the development in detail of the various features of the locomotive are distributed over a long period, and are somewhat difficult to trace. The turning of the exhaust steam into the smoke stack was done by Trevithick as early as 1804, but its effect was greatly increased by Hackworth about 1827, who augmented its power by directing it into the chimney through a narrow orifice. This and the tubular locomotive boiler by Seguin in 1828, the link-motion in 1832, the steam whistle by Stephenson in 1833, the Giffard injector in 1858, and the Westinghouse air brake of 1869, are the most prominent features of the locomotive. [Illustration: FIG. 103.--STEPHENSON’S LINK MOTION.]