This simple device gives a graphic demonstration of the sun’s radiative energy. A large convex mirror concentrates solar radiation onto a small container of water suspended at the mirror’s focal point. In a few minutes, the water boils. The mirror’s angle is adjustable though 180° to allow it to be aimed at the sun at any time of day. Specifications: Mirror Diameter: 30cm Aperture area: 700cm2 Mirror focal length: 16cm Furnace capacity: 20ml Base diameter: 22cm Height: 33 - 45cm (depending upon position) Weight: 480g