A general survey of the growth of new industrial methods in the textile and iron industries marks out three periods of abnormal activity in the evolution of modern industry. The first is 1780 to 1795, when the fruits of early inventions are ripened by the effective application of steam to the machine-industries. The second is 1830 to 1845, when industry, reviving after the European strife, utilised more widely the new inventions, and expanded under the new stimulus of steam locomotion. The third is 1856 to 1866 (_circa_), when the construction of machinery by machinery became the settled rule of industry.
§ 9. Bearing in mind how the invention of new specific forms of machinery in the several processes of manufacture proceeds simultaneously with the application of the new motor-power, we find ourselves quite unable to measure the amount of industrial progress due to each respectively. But seeing that the whole of modern industry has thus been set upon a new foundation of coal and iron, it is obvious that the bonds connecting such industries as the textile and the iron must be continually growing closer and stronger. In earlier times the interdependency of trades was slight and indirect, and the progress in any given trade was almost wholly derived from improvements in specific skill or in the application of specific mechanical invention. The earlier eighteenth century did indeed display an abnormal activity in these specific forms of invention. For examples of these it is only necessary to allude to Lombe's silk mill at Derby, the pin factory made famous by Adam Smith, Boulton's hardware factory at Soho, and the renowned discoveries of Wedgwood. But all increased productivity due to these specific improvements was but slight compared with that which followed the discovery of steam as a motor and the mechanical inventions rendering it generally applicable, which marked the period 1790 to 1840. By this means the several specific industries were drawn into closer unity, and found a common basis or foundation in the arts of mining, iron-working, and engineering which they lacked before.
From these considerations it will follow that the order in which the several industries has fallen under the sway of modern industrial methods will largely depend upon the facility they afford to the application of steam-driven machinery. The following are some of the principal characteristics of an industry which determine the order, extent, and pace of its progress as a machine industry:--