Educational filmstrip from the Society for Visual Education.
This recording has an "audible" frame advance signal for manual-advance filmstrip projectors.
What were filmstrips? See http://en.wikipedia.org/wiki/Filmstrip for information.
If you have the actual film that goes with this recording, please message me as I have the equipment to preserve it. If you have access to any filmstrips, filmstrip records or tapes, or full sets, please message me also, as no one is preserving this type of multimedia.