For demonstrating the high temperatures that may be generated by focusing sunlight in an appropriate manner, and illustrating an 'alternative' method of heating. The apparatus consists essentially of a rear aluminised parabolic mirror, 305mm diameter x 185mm focal length, and a matt black copper receiver vessel, carried upon an arm at the focal point of the mirror.

In clear sunlight the apparatus will rapidly boil water, or melt many fusible substances that are placed in the receiver.

The furnace is supplied in self assembly form, and includes a stand.