Thermo-electric rotation; not: effect of heat on magnetizat.

In 1821 Thomas Johann Seebeck discovered that, when two different metals were exposed to a temperature difference, a small electric voltage is generated at the interface of the two metals. This is also called a thermocouple. This apparatus (now incomplete) was intended to demonstrate this Seebeck-effect. It was provided with two rectangular wire frames, each consisting of two different metals. The wire frames were pivoted at the poles of the magnet. The spirit lamp in the curve of the horseshoe magnet heated the interface between the two metals. This caused a small electric voltage at the interface between both metals, generating a small current in the wire frame. As every electric current creates a magnetic field, the wire frames reacted to the field of the horseshoe magnet and started to rotate.