James David ForbesBorn 20 Apr 1809; died 31 Dec 1868 at age 59.Scottish physicist noted for his research on heat conduction and glaciers. In 1836-44, he described the polarization (alignment of waves to vibrate in a plane) of radiant infrared heat by the mineral tourmaline, by transmission through a bundle of thin mica plates, and by reflection from the surfaces of a pile of mica plates. In 1846 he began experiments on the temperature of the Earth at different depths and in different soils near Edinburgh. Later he investigated the laws of heat conduction in bars, and in his last piece of work reported that iron conducts heat less efficiently as its temperature rises. He was among the first to study glacier movements and was involved with Tyndall in the great glacier controversy of the 1850s. |
