The apparatus, designed by the Dutch physician and physicist Jan Ingenhousz (1730-1799) for the qualitative comparison of the thermal conduction of different materials, consists of a rectangular brass container with wooden handles having horizontal rods of the same size of the different materials protruding from one side.
In the exemplar of the Ingenhousz apparatus presented here, the brass container is 11 cm in height, it has a a width of 22 cm and a depth of 10.5 cm. Eight metal rods of the same size (diameter 0.4 cm, length 8 cm) of silver, copper, iron, zinc, tin, lead, wood and glass protruding from the side are identified by the words: Arg, Ram, Fer, Zin, Pio, Mar, Leg, Vet.