The optical lantern, for instruction and amusement (1890)
Pringle, Andrew · New York, The Scovill & Adams Company · leaf 82
72 THE OPTICAL LANTERN. There are many kinds of reading lamps, intended for nse by the person on the platform. Of course, the object is to throw light on the book or paper without illuminating the screen. By highly ingenious contrivances of this kind we have never been able to read comfortably, and… … Fig. 38. A signal between lecturer and lanternist is generally requi- site ; an electric communication acting on a muffled bell is the neatest device, failing that, we know nothing better than a gentle tap with a knife on a glass of water, or the click of a castanet d la Muybridge. All india-rubber…
Lantern projection
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