Correspondence and papers regarding U.R.S.I. [Union Radio-Scientifique International] programme, 1934-1935

Correspondence and papers regarding U.R.S.I. [Union Radio-Scientifique International] programme of ionospheric research continuing Polar Year work. The material includes a copy of Edward Appleton's paper to U.R.S.I. Commission II on 'Measurement of ionosphere layer heights and correlation with other geophysical and cosmic data’, dated August 1934; manuscript notes of the U.R.S.I. research programme as decided by R.Naismith, dated November 1934; note on U.R.S.I. research, and calendar for 1935 observation days, by J.F. Herd, dated 1934; and comments on U.R.S.I. Congress, by J.F. Herd, sent to Appleton by R. A. Watson-Watt, dated October 1934.