[f. THERMO- + PILE sb.3 5.] A thermo-electric battery, used in connection with a galvanometer, for measuring minute quantities of radiant heat; also called THERMO-MULTIPLIER.
1849. Noad, Electricity (ed. 3), 424. Thermo-piles are now constructed by soldering together at their alternate edges, bars of antimony and bismuth, with squares of cardboard or thick paper intervening.
1871. B. Stewart, Heat, § 165. A square block, containing altogether 25 couples of bismuth and antimony is generally employed, and such an arrangement is called a thermo-pile.
1891. Times, 2 Oct., 3/1. A thermopile … is an apparatus for direct conversion of heat into electricity.
