I have never found any information giving the name of the inventor, if one existed; relevant dates about patents, if any, or first recognized use. I do remember in circa 1920 my father in one of his many changes as a boomer telegrapher was agent-telegrapher at Flippin, Arkansas on the White River Division, Missouri Pacific, had one on the wall. It resembled the old early style wall telephones installed by early day telephone companies. As a matter of fact in later years when telegraphones were present in stations or on-line booths or sometimes post-mounted boxes.
Sometimes they generally had the appearance of these old wall phones including provision of the crank operated ringer; hand held receiver and container at bottom of 'phone set that held two dry-cells. The top of the containers lifted upward on hinges and when closed provided a small writing surface.
An unexpected feature discovered in using these 'phones was that by induction the receivers on the phones acted to give an easily and clearly read sound the same as the telegraph sounders. Several employees on the original Salida-Montrose and Alamosa-Durango, Santa Fe and other branches transferred from telegraph service to train and/or engine service. If and when their train was being delayed for meets or passing or because of presence of some natural or manmade emergency they would go to the nearest 'phone booth or box cut in, put receiver to ear and get a lot of information via the inducted signals (dots/dashes) heard in the 'phone receiver.
Did the telegraphone replace or only supplement the telegraph? It did neither but was rather a system within itself and possible because it could be installed using Morse wires already in place.
The telegraphone was the instrument mounted in the phone booths. No telegraph gear was in any booth. But not only were they in booths, telegraphones were post mounted in protective boxes; in protective boxes fastened to rock walls of canyons; on tree trunks. Section foremen had them, on-line coal supply points where a coal heaver was maintained; at isolated "OS" jobs where operators lived in other than quarters in the depot/station. Essentially they constituted a communication system for used by non-telegraphers.
In the Alamosa Division Timetable issued in 1949, some of telephones (actually still telegraphones) were retained at the worst trouble spots between stations. Telephones (telegraphones) at stations (any permanent structure such as abandoned stations, section houses etc can be found in schedule blocks of the timetable where a "P" is found to the right of a station name.
Telephone use out on the line (remote areas). There were none. All of the new sets were placed in agency-telegraph offices except at following locations (those most trouble prone): MP 311.23, MP 315.2, MP 323.0, MP 328.0 and MP 333.0. Except these, the old telegraphones were left In the various locations more as communication points between section gangs, etc than for general overall use. The phones at the listed locations were definitely put there to report problems. The telegraphones being used when need to report to DS arose. Were they used to routinely report progress? Could be, of course but on the narrow gauge each construction project, wreck clearance, snow job was put in charge of an appropriate competent supervisor. Headquarters waited until the project etc. was completed to get a report. What I'm saying is: situations on the Narrow Gauge were small potatoes and handled by Division supervisors, and Denver or Pueblo did not lose much sleep over the 3-foot gauge.