Colors Made Audible.

Manufacturer and builder ?, 1891

A beam of sunlight is thrown through a lens on a glass vessel that contains lamblack, colored silk or worsted, or other substance. A disk, having slits cut in it, is made to revolve swiftly in this beam of light, so as to make alternate flashes of light and shadow. On putting the ear to the glass vessel, sounds are heared so long as the flashing beam is falling on the vessel. If a beam of sunlight is made to pass through a prism, so as to produce the solar spectrum, and the colored light breaks through the revolving disk, and if, for instance, the vessel contains red worsted, and the green light flashes upon it, loud sounds will be given. Only feeble sounds will be heard when the red and blue parts of the rainbow fall upon the vessel, and other colors make no sound at all. Green silks give sound best in red light. Every kind of material gives more or less or no sound in different colors.