The material consists of 'The existence of more than one ionized layer in the upper atmosphere'. A published version of Appleton's paper presented at U.R.S.I. [Union Radio-Scientifique Internationale] General Assembly, October 1927, announcing his discovery of the F layer; 'Some Observations on International Research on Atmospherics'. A typescript of Appleton's paper presented at Copenhagen meeting, 1931; and U.R.S.I Program of meeting, Washington D.C., 1938.

Lecture by Norman Dott, 'Acoustic Neuromas - the desirability and practicability of total removal'. The paper was given at the Second International Congress of Neurological Surgery, Washington D.C., dated October 1961. The material consists of a synopsis, the text of the lecture, and a list of slides.

The material consists of two copies of report on wave interaction by Radio Research Board for U.R.S.I [Union Radio-Scientifique Internationale] 8th General Assembly, May 1947; and Program of joint meeting, Washington, October 1947.