Economic change generally takes place gradually, and therefore some historians feel it is misleading to speak of an industrial revolution, since the process was clearly evolutionary, rather than revolutionary.
However, growth did not proceed at an even pace, and developments in one country or one sector of industry often altered circumstances so rapidly as virtually to transform styles of life and modes of work within a generation or less. Generally, the growth of industry was identified with the introduction of machine production, making mass markets possible and the factory system essential.
Historians once believed that production expanded most rapidly at moments of economic “take-off” when various factors that had blocked sustained growth were removed by the forces of capitalism. Among the factors often credited with the economic take-off that ushered in the nineteenth century were the rise of a merchant class during the Renaissance, colonialism and mercantilism, the American and French revolutions, the rise of the competitive state system, the Protestant emphasis on hard work and material progress as signs of salvation, the rise of modern science, and the social theories of the philosophes.
Obviously these all played a role, though historians no longer generally agree that a sharp line separated the industrial revolution from the years that preceded it. They do, however, generally agree that between the 1820s and the 1890s industrialization spread from England across Europe and eventually to Russia in four stages.
Initially there was a transition from agricultural to industrial priorities for society. Industrial expansion then accelerated as capital was mobilized, raw materials were secured through treaty or annexation, managerial skills were developed, and unified national states turned to the business of competition for markets, influence, and prestige.
The first developments were in textiles, in which Britain led. The second stage was in metallurgy, in which Belgium joined Britain in leadership until Germany overtook both around 1900 (and the United States, in turn, overtook them). In the third stage the chemical industry developed from improvements in mining techniques.
By the 1850s new methods for recovering minerals from the earth meant that potassium, phosphate, sulfur, and rock salt were the center of attention; these, in turn, made the development of new fertilizers possible, vastly increasing the productivity of the soil. The fourth stage came after the 1890s, first in Britain and Germany, when electricity marked the move to a new form of industry based on more specialized skills.
By 1914 Germany led the world in the production of lights, cables, generators, transformers, ultimately changing both public and private life dramatically by bringing appliances within reach of thousands of purchasers. The age of the consumer had begun.