Timeline of heat engine technology

This timeline of heat engine technology describes how heat engines have been known since antiquity but have been made into increasingly useful devices since the 17th century as a better understanding of the processes involved was gained. A heat engine is any system that converts heat to mechanical energy, which can then be used to do mechanical work.They continue to be developed today. In engineering and thermodynamics, a heat engine performs the conversion of heat energy to mechanical work by exploiting the temperature gradient between a hot "source" and a cold "sink". Heat is transferred to the sink from the source, and in this process some of the heat is converted into work. A heat pump is a heat engine run in reverse. Work is used to create a heat differential. The timeline includes devices classed as both engines and pumps, as well as identifying significant leaps in human understanding. Prehistory - The fire piston used by tribes in southeast Asia and the Pacific islands to kindle fire. c. 450 BC - Archytas of Tarentum used a jet of steam to propel a toy wooden bird suspended on wire. c. 50 AD - Hero of Alexandria's Engine, also known as Aeolipile. Demonstrates rotary motion produced by the reaction from jets of steam. c. 10th century - China develops the earliest fire lances which were spear-like weapons combining a bamboo tube containing gunpowder and shrapnel like projectiles tied to a spear. c 12th century - China, the earliest depiction of a gun showing a metal body and a tight-fitting projectile which maximises the conversion of the hot gases to forward motion. 1125 - Gerbert, a professor in the schools at Rheims designed and built an organ blown by air escaping from a vessel in which it was compressed by heated water. 1232 - First recorded use of a rocket. In a battle between the Chinese and the Mongols. ( see Timeline of rocket and missile technology for a view of rocket development through time.) c. 1500 - Leonardo da Vinci builds the Architonnerre, a steam-powered cannon.