The textile industry was the first to exploit the potentialities of power-driven machinery. Beginning with the spinning jenny in the 1760s, the use of machinery gradually spread to other processes.
In 1793 an American, Eli Whitney (1765-1825), devised the cotton gin, an engine that separated the fibers of raw cotton from the seeds and enabled a single slave to do what had previously required the hand labor of fifty slaves. Meanwhile, British inventors perfected a power-driven loom for weaving cotton thread into cloth. By 1830 Britain operated more than fifty thousand power looms, and cotton goods accounted for half of its exports.
Advances in mechanical engineering made this rapid expansion possible. Earlier, for instance, the difficulty of procuring exactly fitting parts had restricted the output of Watt’s steam engine. Then British engineers, by studying the precision techniques of watchmakers, devised a lathe that turned screws of almost perfect regularity.
They also developed machines for sawing, boring, and turning the pulley blocks used by British ships in the Napoleonic wars. Meantime, Eli Whitney undertook important experiments at his arms factory in Connecticut, using the concept of standardized and interchangeable parts, one of the basic principles of mass production.
New processes in industry were not uniformly adopted, of course. The survival of handicraft techniques and the workers’ fear that they would be displaced by machines also slowed down the process of mechanization. Even in the cotton industry, weaving on the hand loom continued in areas with an especially large reservoir of cheap labor, like Ireland and central Europe, where peasants could produce cloth in their cottages and be paid by the piece. In the woolen and clothing industries, mechanization did not come until the 1850s, when Britain produced a machine for combing wool, and an American, Isaac Singer (1811-1875), popularized the sewing machine.
Coal ranked with cotton as an industry that pioneered in the solution of technical problems. Steam engines were used to pump water from the mines; ventilating shafts and power fans supplied them with fresh air; and safety lamps gave miners some protection against dangerous underground gases. The coal output of Britain, the world’s leading producer, rose steadily from about 16 million tons in 1816 to 65 million in 1856. The consumption of coal mounted because of its increased use as a household fuel in wood-short Britain, its importance in producing steam power, and its vital contribution to the expanding iron industry, which required large quantities of coal to make the coke used in smelting.
The efficiency of smelting advanced rapidly after the development of the blast furnace (1828), in which fans provided a blast of hot air to intensify the action of the hot coke on the iron. Thanks to the blast furnace, Britain produced iron strong enough for use in bridges and in factory buildings.
Yet the best grade of iron lacked the tremendous strength of steel, which is iron purified of all but a minute fraction of carbon by a process of prolonged, intense heating. Steel for industrial purposes could be made in the early 1800s, but only by ruinously expensive methods. Then in 1856 the Englishman Henry Bessemer (1813-1898) invented the converter, which accelerated the removal of impurities by shooting jets of compressed air into the molten metal.
A decade later William Siemens (1823-1883), a German living in England, devised the open-hearth process, which utilized scrap as well as new iron, and which handled larger amounts of metal than the converter could. The inventions of Bessemer and Siemens lowered the cost of making steel so substantially that the world output increased tenfold between 1865 and 1880.