This sub-series consists of 2 gramophone records each inscribed 'A.B.C. [Australian Broadcasting Corporation?] Guest of Honour Sir Edward Appleton August, 1952’ and ‘Recorded at 78 r.p.m. [revolutions per minute] from tape. Use lightweight pickup'. The original tape was recorded at the U.R.S.I [Union Radio-Scientifique Internationale] conference, Sydney, 1952.