William John Macquorn Rankine

William John Macquorn Rankine was a Scottish engineer, born July 5, 1820 in Edinburgh and died December 24, 1872 in Glasgow, whose analysis of the ideal heat engine still describes how steam power plants are modeled today. He began studies at the University of Edinburgh in 1836 but left without a degree, apprenticing instead under the surveyor and engineer John Benjamin Macneill. Working alongside Rudolf Clausius and William Thomson, Lord Kelvin, as one of the founding contributors to thermodynamics, Rankine coined the term potential energy in 1853 and, in the years that followed, worked out a complete theoretical treatment of an ideal heat engine fitted with a condenser, the cycle that bears his name, establishing that its maximum efficiency depends only on the two temperatures between which it operates; the Rankine cycle remains the standard idealized model for a steam power station's efficiency. In 1859 he devised the Rankine absolute temperature scale, based on Fahrenheit degrees. Appointed Professor of Civil Engineering and Mechanics at the University of Glasgow in 1855, a post he held until his death, he published influential engineering manuals on the steam engine and other heat engines through the 1850s and 1860s and became the founding president of the Institution of Engineers and Shipbuilders in Scotland in 1857.