Questions people actually ask

A steam engine is a machine that uses steam to do mechanical work, with heat doing the pushing. Encyclopaedia Britannica: steam engine Steam engines powered locomotives, steamboats, steamships and factory machines. Encyclopaedia Britannica: Industrial Revolution

In a double-acting engine, steam from the boiler is let in to each side of the piston in turn, so it pushes both ways. Encyclopaedia Britannica: steam engine In the classic engine the piston rod drives a crank on a flywheel, which turns the back-and-forth push into round-and-round motion. Encyclopaedia Britannica: steam engine

Hero of Alexandria made the first known “steam engine”, but used it only to power toys and amuse visitors. Encyclopaedia Britannica: Heron of Alexandria In 1698 Savery patented a steam pump: a closed vessel filled with water, with steam let in and then condensed. Encyclopaedia Britannica: Thomas Savery The first recorded Newcomen engine was put up near Dudley Castle, Staffordshire, in 1712. Encyclopaedia Britannica: Thomas Newcomen

In May 1765 Watt came up with the separate condenser, his first and greatest invention. Encyclopaedia Britannica: James Watt Watt’s sun-and-planet gear (1781) turned a shaft twice for every cycle of the engine. Encyclopaedia Britannica: James Watt In 1782 Watt patented the double-acting engine, where the piston pushed as well as pulled. Encyclopaedia Britannica: James Watt

In May 1765 Watt came up with the separate condenser, his first and greatest invention. Encyclopaedia Britannica: James Watt Watt’s engines burned two-thirds less coal than Newcomen’s. Science Museum blog: James Watt and the separate condenser

A flywheel’s inertia resists changes in speed, smoothing out the jerky pushes of the piston. Encyclopaedia Britannica: flywheel

Trevithick built the world’s first steam railway locomotive in 1804. Science Museum blog: Steam train in Kensington Gardens On 21 February 1804 a Trevithick engine won a bet by hauling 10 tons of iron and 70 men along 10 miles of tramway. Encyclopaedia Britannica: Richard Trevithick

Rocket won the Rainhill Trials in October 1829, a public contest run by the Liverpool and Manchester Railway with £500 on offer. Science Museum blog: Stephenson’s Rocket returns to Newcastle Rocket’s big ideas were its multi-tube boiler and using exhaust steam to draw air through the firebox. Encyclopaedia Britannica: locomotive Britannica says railway steam became a commercial success with Rocket in 1829. Encyclopaedia Britannica: steam engine

Puffing Billy, built in about 1814 by William Hedley, is the oldest surviving steam locomotive in the world. Science Museum blog: Steam train in Kensington Gardens

One horsepower is 33,000 foot-pounds of work a minute. Encyclopaedia Britannica: horsepower James Watt fixed the horsepower after experiments with strong dray horses, and his figure is about 50 per cent more than an average horse can keep up. Encyclopaedia Britannica: horsepower One horsepower is about 746 watts. Encyclopaedia Britannica: horsepower

In a steam turbine, the steam rushes out of nozzles at high speed and spins the blades directly, with no piston at all. Encyclopaedia Britannica: steam engine Sir Charles Parsons invented the modern steam turbine in 1884, passing steam through rows of rotors that get bigger as the steam expands. Encyclopaedia Britannica: steam turbine

In the mid-1600s Robert Boyle studied how the pressure and volume of a trapped gas are linked. NASA Glenn Research Center: Boyle’s law In the classic engine the piston rod drives a crank on a flywheel, which turns the back-and-forth push into round-and-round motion. Encyclopaedia Britannica: steam engine

Yes: see our no-heat experiments, from a syringe squeeze to a stair-climb horsepower test.