Rankine (unit)

The Rankine scale is a temperature scale named after the Scottish physicist and engineer 1820 − 1872), Willam John Macquorn Rankine, who proposed it in 1839. The symbol for a degree Rankine is °R and it is based on one degree Rankine being equal to one degree Fahrenheit. As with the Kelvin scale, zero in the Rankine scale is absolute zero. A temperature of −459.67 °F is exactly 0 °R.

The melting point of water in the Rankine scale is 491.67 °R and the normal boiling point of water is 671.67 °R (i.e., 459.67 + 212).