The Melloni bench is an optical bench for the study of thermal radiation. It consists of a graduated horizontal rule attached to a wooden platform on which we also find on sliding supports a source, a detector and different accessories.
The detector is a differential thermoscope of the highest sensitivity which is composed of a thermoelectric pile made up of several tens of antimony-bismuth couples connected to a Nobili astatic galvanometer.
In this device, designed in 1829 by Leopoldo Nobili (1784-1835), who called it an electric thermoscope or thermomultiplier, and which was later perfected by Macedonio Melloni (1798-1854), the bars of antimony and bismuth in the pile are soldered in zigzag fashion so as to form a parallelepiped with a square base in which the odd-numbered soldered joints are all on one base and the even-numbered ones on the other base and the two bases are blackened.
On the bench presented here, which was part of the equipment acquired in 1864, the rule is brass, one metre long, it lies on a base of mahogany (width 75 cm, depth 16 cm) and is equipped with a drawer for accessories.
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