MECHANICAL IMPROVEMENT.--During the period 1840-60 mechanical improvement was more remarkable than in earlier periods. The first iron-front building was erected, the first steam fire engine used, wire rope manufactured, a grain drill invented, Hoe's printing press with revolving type cylinders introduced, and six inventions or discoveries of universal benefit to mankind were given to the world. They were the electric telegraph, the sewing machine, the improved harvester, vulcanized rubber, the photograph, and anaesthesia. [Illustration: MORSE AND HIS FIRST TELEGRAPH INSTRUMENT.] THE TELEGRAPH.--Seven years of struggle enabled Samuel F. B. Morse, helped by Alfred Vail, to make the electric telegraph a success, [8] and in 1844, with the aid of a small appropriation by Congress, Morse built a telegraph line from Baltimore to Washington. [9] Further aid was asked from Congress and refused. [10] The Magnetic Telegraph Company was then started. New York and Baltimore were connected in 1846, and in ten years some forty companies were in operation in the most populous states. [Illustration: HOWE'S FIRST SEWING MACHINE.] THE SEWING MACHINE; THE HARVESTER.--A man named Hunt invented the lockstitch sewing machine in 1834; but it was not successful, and some time elapsed before his idea was taken up by Elias Howe, who after several years of experiment (1846) made a practical machine. People were slow to use it, but by 1850 he had so aroused the interest of inventors that seven rivals were in the field, and to their joint labors we owe one of the most useful inventions of the century. From the household the sewing machine passed into use in factories (1862), and to-day gives employment to hundreds of thousands of people. [Illustration: EARLY HARVESTER. From an old print.] What the sewing machine is to the home and the factory, that is the reaper to the farm. After many years of experiment Cyrus McCormick invented a practical reaper and (1840) sought to put it on the market, but several more years passed before success was assured. To-day, greatly improved and perfected, it is in use the world over, and has made possible the great grain fields, not only of our own middle West and Northwest, but of Argentina, Australia, and Russia. VULCANIZED RUBBER; PHOTOGRAPHY; ANAESTHESIA.--The early attempts to use India rubber for shoes, coats, caps, and wagon covers failed because in warm weather the rubber softened and emitted an offensive smell. To overcome this Goodyear labored year after year to discover a method of hardening or, as it is called, vulcanizing rubber. Even when the discovery was made and patented, several years passed before he was sure of the process. In 1844 he succeeded and gave to the world a most useful invention. [Illustration: A DAGUERREOTYPE, IN METAL CASE, 1843.]