The collection contains a wide range of papers relating to the activities of the Greenwich Observatory during Dyson's time in office, with some additional material from other periods. There is considerable material concerning the internal affairs of the Observatory, including its removal to Herstmonceux Castle, staff, instruments, visitors and Visitations, publications and garden parties. There are papers on the Cape Observatory and Nautical Almanac Office, as well other societies and organisations, such as the Royal Society and Royal Astronomical Society. Other subjects covered include magnetism, the measurement of time, geodesy, eclipses, planetary and lunar theory, stars, comets and meteors.