Sir James Dewar (1842-1923), Chemist
Sitter in 5 portraits
A physicist whose study of low-temperature phenomena included the use of a double-walled vacuum flask of his own design that has been named after him. He was also the first person to liquefy and solidify hydrogen gas. Dewar was appointed professor at the University of Cambridge in 1875 and at the Royal Institution two years later. He held both posts throughout his life. In around 1892 he came up with the idea of using vacuum-jacketed vessels for the storage of low-temperature liquid gases. The resulting device was so efficient in maintaining the temperature of gases that it became an essential tool in low-temperature scientific work. The principle Dewar invented formed the basis for the thermos flask.