The collection comprises manuscript notebooks, printed pamphlets, correspondence, a minute book, and photographic and other catalogues, 1768-1970. These notably include notebooks containing descriptions and viewing data relating to astronomical observations carried out at Kew Observatory, Richmond, Surrey, on behalf of King George III, with a printed pamphlet by Nevil Maskelyne, Astronomer Royal, entitled Observations of the transit of Venus over the Sun , 1768-1769; manuscript notebook containing measurements recorded during a test of the accuracy of the H5 chronometer designed by John Harrison, 1772; manuscript notebooks recording daily temperature, barometric, hygrometric and rainfall readings taken at Kew Observatory, Richmond, Surrey, 1773-1840; a printed pamphlet by George Atwood, Fellow of the Royal Society, entitled A Supplement to 'A treatise on the construction and properties of arches' (London, 1804), with manuscript dedication to King George III and related correspondence, 1804-1805; a folio signature book of visits by dignitaries to the George III Museum, 1843-1929; manuscript diary describing the work of the George III Museum including the upkeep of equipment and use of exhibits in experiments, 1850-1880; manuscript minutes of the George III Museum Committee charged with managing the collection, 1880-1885; catalogues relating to the collection, [1841-1970]; correspondence by George Calver, astronomer, relating to telescope design, 1897; series of copper plates and labels advertising the George III Museum, [1841-1926].