The material relates to U.R.S.I. [Union Radio-Scientifique Internationale] and M.C.I. [Mixed Commission on the Ionosphere] affairs, including Third Polar Year proposed for 1957-1958 and some research matters are discussed. There is also included a U.R.S.I. report on 'Terminology and units' with a letter from D.F. Martyn.

Correspondence from D.F. Martyn to Edward Appleton, dated 1937, 1948-1955. The material relates to various research problems, U.R.S.I. [Union Radio-Scientifique Internationale], data exchange, and enclosing drafts or headlines for reports.

Correspondence from D.F. Martyn to Edward Appleton, dated 1948-1949. The material mainly relates to U.R.S.I. [Union Radio-Scientifique International] reports.

Correspondence from D.F. Martyn to Edward Appleton, dated 1946. The correspondence is mainly regarding a paper by Martyn on Solar tides, submitted to Appleton for communication to the Royal Society. The material includes comments on Martyn's paper by W.J.G. Beynon 1947, and an enthusiastic letter by S. Chapman, 1946 and Appleton's notes on papers by Martyn on atmospheric tides, given at a meeting of the Mixed Commission on the Ionosphere, 1948.

U.R.S.I [Union Radio-Scientifique Internationale] report on 'Extra-terrestrial radio noise'. The report was sent with a covering letter by D. F. Martyn, dated 1950.