Eighty years ago, this second period class somewhere in America was getting ready for its radio geography lesson. While the teacher points out western Africa on the map, the audio expert at the back of the room is preparing to cue in a radio lesson on the subject, which will presumably be piped in through speaker number 1 above the map.

He’s pulling in the program on the four-tube tuner described in the February 1941 issue of Popular Mechanics. It’s a TRF tuner which is selective enough to separate the local stations, but has sufficient bandwidth to provide good reception of musical selections. The set can be run through any audio amplifier. In this case, the school is progressive enough to have a public address system installed, and the students will hear the program through it.