Lord Kelvin (26 June 1824 – 17 December 1907) was a British mathematician, mathematical physicist and engineer. Born in Belfast, he was Professor of Natural Philosophy at the University of Glasgow for 53 years, where he undertook significant research, including on electricity and the formulation of the first and second laws of thermodynamics. He was also the first to determine the correct value of absolute zero, and the Kelvin scale of temperature is named in his honour. Kelvin received the Copley Medal in 1883, served as the president of the Royal Society from 1890 to 1895, and in 1892 became the first British scientist to be elevated to the House of Lords. This photograph, taken circa 1900, shows Kelvin resting on a binnacle (the stand for a marine compass) of his invention, and holding a marine azimuth mirror.

Photograph credit: T. & R. Annan & Sons; restored by Adam Cuerden