This amazing contraption is called a“PhotoTypositor” which was manufactured by Visual Graphics Corporation. It was quite popular for setting type, one character at a time, back in the 70s and 80s. This is actually a more modern version of the “Model K” that I worked with from 1977 to around 1980. I used to know what all the knobs and dials did back then.
Here are the basics of how it worked, based upon my memory from over 25 years ago:
First you would need to mix up a batch of chemicals; developer, fixer, stop bath and wash water with measured plastic bottles and place them into areas 22, 10 and 9 respectively. You would have to give the plastic bottles a squeeze to prime the developer and fixer cells. These chemicals contained cyanide which would burn your clothes and skin. You would load a roll of light sensitive white paper in a darkroom and thread it through the Typositor (TP) via various compartments and levers starting in area 21.
Next you would load a font which was actually a 2" high by about 12 ft. long strip of negative film, mounted on two black plastic reels and thread it through areas 27, 28 and 4 sequentially. You would need to do all of this in low level lighting (red or yellow bulbs) to avoid exposure problems. Next you would set the “point size” of the type by lowering or raising the rear part of the machine. Various switches and knobs adjusted the focus, position, alignment and other aspects of the elaborate optics system in areas 1, 2 and 26 among others. You could also condense, expand and slant type using various lenses and adjustments in areas 29, 15 and 15A (the entire base would swivel for slanting type).
Finally, while looking through the viewfinder (23), you would spin a knob to select the desired character, flash a strobe light for the proper exposure time (varied per point size from around 18 to 120 pt.) and watch the character develop before your eyes. Then you would expertly slide the paper with the exposed character a precise amount to the left to control the letterspacing (kerning) and repeat the process by selecting another character which you would see as a “ghost image” superimposed in yellow light, prior to exposure.
The entire process would take an expert about 30 minutes from a cold start (it was a high maintenance machine) to set a single line of type. Subsequent “lines of TP” could be bumped out in about five minutes. TP was typically sold by the inch and a foot would sell for around $50 or more to Madison Avenue Ad Agencies in NYC, which is who we provided with overnight service. I set several miles of TP over the years, much of which was 18 pt. Brush Script.