\Ther"mo*pile\, n. [Thermo- + pile a heap.] (Physics)
An instrument of extreme sensibility, used to determine
slight differences and degrees of heat. It is composed of
alternate bars of antimony and bismuth, or any two metals
having different capacities for the conduction of heat,
connected with an astatic galvanometer, which is very
sensibly affected by the electric current induced in the
system of bars when exposed even to the feeblest degrees of
heat.