A device for exhibiting the primary colours by the action of the breath on a specially prepared plate of highly polished black glass.

An instrument specially designed for the production and examination of spectra.

A spectroscope for use with the sun. Now historical.

An instrument consisting of a combination of coloured glasses formerly used to exhibit certain optical properties of chlorophyll, and causing…

An optical instrument producing complementary colours side by side.

An instrument used for radioscopy; spec. = fluoroscope, n.

An instrument in which the rays emitted from the metal radium are evidenced by the production of tiny sparks.

Physics. An instrument in which alpha rays are detected by the flashes of light which are emitted when they strike a fluorescent screen.

a camera which uses the principles of streak photography; also, an electron-optical analogue of this allowing the resolution of events of the order…