The sudden acceleration of technical and economic development that began in Britain in the second half of the 18th century. The traditional agrarian economy was replaced by one dominated by machinery and manufacturing, made possible through technical advances such as the steam engine. This transferred the balance of political power from the landowner to the industrial capitalist and created an urban working class. From 1830 to the early 20th century, the Industrial Revolution spread throughout Europe and the USA and to Japan and the various colonial empires.

The term `Industrial Revolution´ has been criticized on the grounds that it implies a sudden and dramatic change, whereas the process of industrialization was long drawn out, erratic, and varied from industry to industry and from region to region. It should be understood in the context of the continuing social and political changes, agricultural innovations, accumulation of capital, and expansion of trade which had taken place in the 17th century and earlier.

Britain exhibited a combination of favourable circumstances for such a change: an increasing population creating a larger workforce; natural resources, especially a plentiful and accessible supply of coal; raw materials from its colonies; expanding markets in its increasing population and its colonies; a strong middle class and comparatively stable political system; and a sound monetary system and cheap capital as a result of low interest rates, essential for the high levels of investment required in the new technology.

Technological, political, and social change The Industrial Revolution brought many changes. New materials, basically iron and steel, were used as well as new energy sources, such as coal and the steam engine, and most obviously new machinery, particularly in the textile industry. Transport systems were revolutionized by steam trains, canals, and better roads. As cottage industries were replaced by the factory system, new methods of labour organization were employed, bringing specialization, the division of labour, and new relationships between employer and employee.

The new working conditions led to political changes as wealth moved away from the land and towards the new manufacturing classes and there were massive social changes brought about by internal migration, a rising population, and the growth of urban areas.

Textile industry
The textile industry saw most of the early benefits of these innovations. The flying shuttle was invented 1738, rendering the old process of carrying the weft through the threads of the warp obsolete and enabling the weaver to double output. This in turn led spinners to seek mechanical aids to meet the increased demand for yarn. These innovations were swiftly followed by others, notably James Hargreaves's `spinning jenny´ about 1764, Richard Arkwright's water-frame spinning roller 1768, and Samuel Crompton's `spinning mule´, a combination of Hargreaves's jenny and Arkwright's water-frame, 1779. Edmund Cartwright's power loom was not perfected for another 25 years but by that time his Doncaster factory was equipped with a steam engine and a year or two later hundreds of his looms were selling to Manchester firms. Gradually the power loom began to be used in the woollen industry as well as the cotton trade for which it had been invented.

Steam power
Perhaps the most obvious single enhancement was the general replacement of water power by steam, made possible by James Watt's steam engine. Watt's various patents were taken out 1781-85, after which time the change from water power to steam made rapid progress and mills and factories were set up near the coalfields, where fuel was cheaper. Later the ironmasters began to investigate the use of coal as a smelting fuel, and with improved production methods the output from their furnaces increased rapidly.