"Pair Of Burning Mirrors"
Pair of burning mirrors. Such a device allows to demonstrate that heat propagates by radiation like light. The device consists of two concave (parabolic) metal mirrors. At the focus of one mirror, there are burning coals, and at the focus of the other mirror one places a material (such as tinder). If the two mirrors are facing each other, the light radiated from the charcoal arrives on the tinder which catches fire. End of the XIXth century. The base of the feet measures 21cm in diameter. 
Le Magazine de PROANTIC
TRÉSORS Magazine
Rivista Artiquariato