What is megalethoscope print?
megalethoscope print meaning in Information Science terminology / glossary / dictionary is:
A photographic print made on thin translucent paper or canvas, colored and specially mounted on a curved frame for viewing as parlor entertainment in a megalethoscope, a large viewing device patented in 1862 by Swiss-born optician and photographer Carlo Ponti. The device contains a large magnifying lens, which gives the illusion of depth and perspective when the albumen photographs are either backlit by an internal light source (usually an oil lamp or kerosene lantern) or lit by daylight admitted through a system of doors and mirrors. When illuminated by daylight, a daytime view appears; when lit from behind, the slide is transformed into a colorful nocturnal tableau. The slides were sometimes pierced to create special dramatic effects (click here and here to see examples).