TAIT, PETER GUTHRIE

born April 28, 1831, Dalkeith, Midlothian, Scot. died July 4, 1901, Edinburgh Scottish physicist and mathematician who helped develop quaternions, an advanced algebra that gave rise to vector analysis and was instrumental in the development of modern mathematical physics. After serving from 1852 to 1854 as a fellow and lecturer of Peterhouse College, Cambridge, Tait took a professorship in mathematics at Queen's College, Belfast. There he joined the noted Irish chemist Thomas Andrews (181385) in researches on the density of ozone and the effect of electric discharges on oxygen and other gases. From 1860 he was professor of natural philosophy at the University of Edinburgh. Tait made fundamental contributions to the theory of quaternions, as evidenced in Elementary Treatise on Quaternions (1867), which went through three editions. Later he wrote Introduction to Quaternions (1873). In collaboration with the English physicist Sir William Thomson (later Lord Kelvin), Tait produced Treatise on Natural Philosophy (1867), which traced the concept of conservation of energy to the work of Sir Isaac Newton. Their efforts were vital to the newly emerging concept of energy and its properties. After Tait published Treatise on Natural Philosophy, he concentrated on studies of thermoelectricity and thermal conductivity (the capacity for heat flow). With the Scottish physicist Balfour Stewart he wrote The Unseen Universe (1867). Such was the public response that they released a sequel, Paradoxical Philosophy (1878).