scotographs

Noun

scotograph (plural scotographs)

1. (obsolete, rare) An instrument for writing in the dark, or by the blind.
   • Scotograph or writing-machine for use of the blind1896 January 28, Thomas J. Bennett, Scotograph or writing-machine for use of the blind, US Patent 553504 (PDF version), title
2. (obsolete, rare) An impression made on a photographic plate by a radioactive substance without the intervention of any opaque object other than the screen of the plate.
   • "Scotograph" is likely to stick as the popular term for portraits taken by the Röntgen process. It means "shade picture," and its analogy with photograph, which is a "light picture," is sufficiently manifest to help on its vogue.1896, Western Electrician, page 105
3. An image of a ghost or other apparition appearing on unexposed film.
   • The spirit-faces are sometimes obtained on ordinary paper without the aid of a camera and are called Scotographs.1946, The Kalpaka, page 49