William John Macquorn Rankine

Born 5 July 1820 in Scotland, Rankine trained as both mathematician and physicist before turning to the young science of thermodynamics in the 1850s. Alongside Clausius and Kelvin, he helped establish its First Law and developed the Rankine temperature scale, a Fahrenheit analogue to Kelvin's. His complete theory of heat engines — steam and otherwise — appeared in engineering manuals published through the 1850s and 1860s that remained standard texts for decades. From 1840 onward he published several hundred papers across botany, music theory, number theory, and nearly every major branch of sci…