Crookes Radiometer

A classic scientific device and tabletop curiosity which demonstrates how light converts to mechanical action in a heat engine. Invented in 1873 by British chemist and physicist Sir William Crookes (1832-1919), watch as the metal vanes of the Crookes Radiometer spin through the power of light alone. They will spin faster with greater light intensity and the device works with natural, artificial and even localised infrared radiation. Set inside a glass bulb, which acts as a partial vacuum, the metal vanes each have a light/reflective and dark/non-reflective surface. As the vanes spin, the reflective properties of the vanes react to the light source, no batteries or other power required. Fascinating to watch and display.

Glass with metal vanes and spindle
15.5cm tall x 7.5cm dia
Box printed with brief instructions
21 x 11 x 11cm box
Age 14+