• Webster's Revised Unabridged Dictionary
    • n Photoscope (Physics) Anything employed for the observation of light or luminous effects.
    • ***
Century Dictionary and Cyclopedia
    • n photoscope An instrument or apparatus for exhibiting photographs.
    • n photoscope An instrument consisting of a selenium-cell, or an arrangement of some other substance whose electrical resistance varies with the degree of illumination, together with a telephone-receiver placed in the same electrical circuit, by means of which the varying intensities of light may be detected.
    • ***


Webster's Revised Unabridged Dictionary
Photo-, + -scope,


In literature:

Phantoscopes, Bioscopes, Photoscopes, and many other instruments followed in quick succession.
"The Romance of Modern Invention" by Archibald Williams