Experimental notes, working papers, correspondence and lecture summaries compiled by Charles Wheatstone, 1836-1875, and photographs collected by him in that period. Notably including papers relating to the development and testing of the telegraph, [1836-1960]; descriptions of experiments and test results concerning the measurement of electromotive forces and electrical potential, [1840-1875]; experimental observations on the nature of magnetism, electricity and thermodynamics, including electromagnet design, batteries and dynamos, [1834-1855]; working papers relating to optics including experiments into refraction, colouration of compounds and polarisation, [1850-1875]; drafts of lectures on sound and musical instruments prepared by Wheatstone, [1832-1837]; material relating to the management of the Wheatstone collection of scientific instruments and library, 1890-1992; biographical material relating to the life of Wheatstone, the invention of the telegraph and Wheatstone's musical instrument manufacturing business, with unrelated newspapers, 1757-1975; stereoscopic photographs and glass negatives taken by Roger Fenton, Samuel Buckle, Jules Duboscq and others, featuring landscapes, still lifes, panoramic scenes of cities including Paris and Moscow and the interior and exterior of the Crystal Palace, Hyde Park, Sydenham, 1851, and especially the Exposition Universelle, Paris, 1855, [1850-1901]; artefacts from Department of Physics, King's College London, including demonstration equipment, telegraph apparatus, a nail fiddle and other prototype musical instruments, [1834-1875]; exhibition of scientific and musical instruments, [1834-1875].

Map of area around the Black Sea, Caspian Sea and Eastern Mediterranean, including Turkey and parts of the USSR, North Africa and the Middle East, drawn up by the Survey Department, Egypt, 1913, and the Royal Geographical Society, under the direction of the Geographical Section of the General Staff, 1916 and 1918, marked with the boundaries of Armenia and Georgia as laid down by the Treaty of Alexandropol, 1920, lines in the Caucasus held by the Turks and by the Bolsheviks, Mar 1921, and boundaries in the Caucasus proposed by Moscow, 1921.

The collection consists of pamphlets written by Davidson, papers relating to his part in the Allied Military Mission to Moscow, USSR, 1939 and papers relating to his career in World War Two as Commander in the Royal Artillery and as Director of Military Intelligence. The World War Two material includes maps used in the retreat of the BEF (British Expeditionary Force) to Dunkirk, France, maps used as Director of Military Intelligence to illustrate the progress of the war to Queen Mary, mother of George VI and a personal diary kept while Director of Military Intelligence. There is also a file containing correspondence with E E Thomas of the Cabinet Office Historical Section relating to aspects of Military Intelligence during World War Two.