The Rankine scale is an absolute scale of thermodynamic temperature named after the University of Glasgow engineer and physicist W. J. M. Rankine, who proposed it in 1859. As on the Kelvin scale, which was first proposed in 1848, zero on the Rankine scale is absolute zero, but a temperature difference of one Rankine degree is defined as equal to one Fahrenheit degree, rather than the Celsius degree used on the Kelvin scale. In converting from kelvin to degrees Rankine, 1 °R = 5/9 K or 1 K = 1.8 °R. A temperature of 0 K is equal to 0 °R.