Extensive correspondence of Sir Joseph Larmor relating to his work on electromagnetic theory, optics, analytical mechanics, and geodynamics.

Correspondence and papers relating to the Royal Society relations with the International Council of Scientific Unions (ICSU), current files contain:

a) British National Committee for Geodynamics (BNC Geodynamics) 8 files, 1970-1980

b) International Union of Geodesy and Geophysics (IUGG) 24 files, 1963-1980

c) International Union of Pure and Applied Chemistry (IUPAC) loose papers, 1980-1982

d) International Union of Radio Science (URSI) 6 files, 1968-1976

e) International Biological Programme (IBP) 4 files, 1970-1975 (but a much larger collection of IBP papers from the Society's modern records centre has been microfilmed between 2001-2005 and the originals destroyed because of their poor physical condition). The archive holds mateial relating to the International Geophysical Year (IGY), 1957-1958, particularly the establishment, administration and scientific results from the Royal Society Base at Halley Bay, Antarctica.