It was T. Seebeck who discovered, in 1821, the effect which now bears his name . He observed that a current flows in a closed loop oftwo dissimilar metals when theirjunctions are at two different temperatures. As Ohm's law was not formulated by G. S. Ohm until 1826, the quantitative description of this phenomenon was not possible at the time of its discovery . In 1834, I.C.A. Peltier, discovered that a junction of two dissimilar metals is respectively heated or cooled when a current is passed through it either in one direction or the other. This phenomenon...