This epidiascope (projector that can project using both opaque and transparent sources) was manufactured by the Charles Beseler Company of New York, New York, likely in the 1910s.
Glass Slides/Transparent Projections
It can hold two glass slides in a sliding tray mechanism at the front. The operator can quickly switch the projection between these two slides, and change out the non-viewed slide. This allows a more seamless transition between slides.
The focus of the projection can be adjusted using a small brass-colored dial near the front of the device.
Opaque Projections
There is a toggle that moves a mirror to swap the projector from "glass slide" to "opaque" projector mode.
There is a tray underneath the projector to hold something flat, is then projected onto a screen.
