Prototype of the thermopile invented by Nobili. Consists of twelve large bismuth and antimony elements, set in mastic, arranged in a circle and protruding from their wooden cylindrical container with screw-on base. The elements were not protected by a lid. They were placed upright in a brass ring secured to an adjustable support, and were screened by a wooden disk with a 15-mm central aperture. Provenance: Lorraine collections.