Recently I came across a piece of ionospheric history; namely, the record of a discussion symposium held at State College, Pennsylvania, in July 1950. The symposium was part of a conference on ionospheric physics sponsored by Pennsylvania State College and “Air Force Cambridge” (AFCRL, now the Space Vehicles Directorate of the Air Force Research Laboratory). As far as I am aware, this conference was the first large gathering devoted to the physics of the ionosphere; the topic of radio propagation, which hitherto had largely dominated ionospheric science, was hardly mentioned except as a tool for the physics. The proceedings of this one symposium fill 21 typescript pages with several pages of diagrams, which were, no doubt, run off on an old-fashioned office duplicator. I have tried to select salient points, adding a few comments from a 2002 perspective in brackets (…).