The partnership, that began in 1775, had most far reaching effects. It was, in fact, the union of one of the most inventive brains of the age with one of the first great commercial intelligences, for the purpose of selling the most valuable thing in existence—" power."
Moreover, it was a form of power that was applied most readily to the production of coal which, after the first half of the eighteenth century, had replaced agriculture as the main prime source of capital.1 This translation from agriculture to industry, meant a change from a country with limited powers of development, to one with enormous scope for expansion. The getting of coal meant the getting of power and the getting of wealth; while the steam-engine, which was invented to meet the demand for pumping power,2 was the chief instrument in the rapid increase in capital that took place. The fact that Britain was the country in which the steam-engine was invented, and, consequently, was the first great coal nation to put her coal to economic use, was the secret of her rapid comparative advanced.3
But the invention of the steam-engine had more than this general and direct effect on the accumulation of capital. For the industries that needed " power to order " it had a peculiar significance. For them it meant the development of a machine economy, and an increase, variously great, in the amount of their fi8ed capital. Moreover, its effect on the labour power employed was two sided in the long run, it largely increased the number of labourers required and reduced the importance of technical skill, but in individual industries it completed the breach between employer and employed—they were separated completely. A capitalist class had been e