Projection apparatus, accessories and slides (1910)
McIntosh Stereopticon Co · Chicago : McIntosh Stereopticon Company · leaf 135
MCINTOSH STEREOPTICON CO., CHICAGO, ILL., U. S. A. 213 INTERCHANGEABLE CHROMATROPE* With Detachable Crank. … A chromatrope is a mechanical slide which produces on the screen a curious change of pattern and effect by the rotation in opposite di- rections of a pair of glass discs, having painted upon them the same geometrical designs in transparent brilliant colors, the effect being caused by the crossing…
Slides (Photography)
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.