Amazing that the arguments about the presence or absence of a luminiferous ether made its way into parts advertisements in a radio magazine. This is from Radio for January 1923. (About 18 months before my dad was born.)
BTW that capacitor looks very nice, and would almost certainly still work. I have caps like that in my junk box. The shape of the blades helps address one of Pete Juliano’s complaints about analog oscillators — the inconsistent spacing of frequencies on the dial.
Thanks to the K9YA Telegram for posting this.