Throughout most of human history, the production of finished products has been a relatively simple and manual task. Even the most complex projects relied on simple hand-held tools and a considerable amount raw human labor. Machines dramatically increased the amount of goods that a single individual could create and led gradually to the diversification and specialization of tasks. Both the waterwheel and windmill captured energy from natural sources to convert it into mechanical power for a variety of uses – sawmills, grain mills, bellows, etc. Although both were ancient inventions, use of the waterwheel in Europe had been universal since antiquity, but windmills were not in widespread use until the twelfth century. Both machines substantially increased the power and productivity of humans by the High Middle Ages, and they remained the principle sources of machine power until the Industrial Revolution of the eighteenth century.
The development of steam engines in the eighteenth century allowed for reliable mechanical power without reliance on flowing water. The freedom that steam engines provided significantly increased the use of mechanical power in production processes (and was one of the driving forces behind the Industrial Revolution). Both Newcomen’s and Watt’s steam engines relied on atmospheric pressure to drive pistons: the condensation of steam within sealed cylinders created a vacuum that allowed the surrounding air pressure to push the piston into the cylinder. Although a substantial advance from both waterwheels and windmills, these steam engines were relatively inefficient and had to be very large to produce suitable amounts of energy. By the early nineteenth century, steam engines had been improved to rely on the pressure of expanding steam to drive pistons and thus were more efficient and powerful. Steam engines remained the dominant source of mechanical power until the development of both the internal combustion engine and the electric motor in the later nineteenth and early twentieth centuries. Mechanization combined with new techniques of production – standardized, interchangeable parts and assembly lines – to generate a massive expansion of industrial output during the late nineteenth and early twentieth centuries. Scientific management helped to standardize processes and procedures, and the gains in efficiency helped to boost production even further.