Mechanization

Mechanization is the process of shifting from work done primarily by hand or with animals to work performed by machinery. In an early engineering text, a machine is defined as something interposed between a moving power and the work to be done, adapting one to the other. While mechanization includes hand tools, modern usage refers to machinery more complex than simple tools, involving devices that change speed or convert motion—such as gears, pulleys, shafts, cams, and cranks. After electrification, mechanization became synonymous with motorized machines. The extension of mechanization into automated production uses closed-loop systems with sensor feedback.

Historically, water wheels from the Roman period ground grain and lifted irrigation water. By the 13th century, water wheels powered sawmills and trip hammers for tasks like crushing ore, as depicted in the 1555 mining text *De re metallica*. Clocks were among the most complex early mechanical devices, and clock makers advanced machine tools and gear design mathematics. Improved gear designs, such as epicycloidal teeth introduced around 1650 and involute gears in the 18th century, reduced wear and increased efficiency. The Industrial Revolution began with textile machinery like the spinning jenny and water frame in the 1760s. Demand for metal parts spurred machine tool inventions from the late 1700s to mid-1800s, with iron replacing wood in gearing by the early 19th century. Self-acting machine tools appeared in the 1840s. Agricultural mechanization included Jethro Tull’s seed drill around 1700, horse-drawn reapers and threshers in the late 18th and early 19th centuries, steam-powered threshing by the late 19th century, and internal combustion tractors in the early 20th century. Hydraulic and pneumatic devices powered mechanical actions in the mid-to-late 19th century, such as positioning tools, pile drivers, and conveyor filling. By the early 20th century, machines like the 1905 glass bottle maker replaced skilled craftsmen, and after 1900, factory electrification enabled electric motors to perform complex operations, leading to mechanized manufacturing of nearly all goods.