steam‐engines

steam‐engines are machines employing steam pressure and condensation to generate motion. Thomas Savery's device (1698) pumped water by partial vacuum, without moving parts, and while engines on his principles were still in use in the 1790s, Newcomen's atmospheric cylinder/piston engine in 1712 established the fundamental principles of steam‐power. James Watt's separate condenser of 1769 became a source of much‐improved technical efficiency once Wilkinson's improved cylinder boring became available (1774).

Mine drainage was its primary application, many engines running on unsaleable slack, with brewing and milling, water supply, and textiles following. Wider applications from the 1790s owed more to Trevithick's high‐pressure non‐condensing and direct acting engines, which powered the first successful marine applications with Symington's Charlotte Dundas (1802), steam carriage (1801), and locomotive (1804).

Stephenson long‐boiler and Kitson outside‐frame locomotives established the basic pattern of railway motive power. From the Grand Junction's establishment of Crewe (1837), British railways manufactured their own locomotives. The economical compound steam‐engine was little used on British railways, where coal was cheap, whereas it became a standard unit for factory power, and in its ultimate triple‐expansionform (after 1880) the key to British shipping and shipbuilding dominance. From the early 1900s, Parsons's marine steam turbine provided still greater speed and economy.