The black wooden base carries a lead stabilizing ring painted red. The glass protection dome is missing. The coil, wound on a boxwood bobbin, has many windings of fine wire, probably silver, covered with silk. Leopoldo Nobili used this type of galvanometer with the thermopile for experiments on radiant heat. He thus named the instrument a "thermomultiplier," by analogy with the "multiplier," the name Johann Salomon Christian Schweigger gave to his original crude instrument.