Correspondence regarding eclipses, including letters concerning the eclipses of 28 April 1911, 24 August 1914, 21 September 1922, 14 January 1926, 29 June 1927, 9 May 1929, 21-22 October 1930, 31 August 1932, 19 June 1936 and 29 May 1938. The correspondence is concerned principally with the choosing of sites, the shipping of equipment, insurance, payment for observers and results. There is correspondence on the instruments left in Russia at the beginning of the First World War and letters regarding the attempt to verify Einstein's displacement theory. Other items include a copy of the 'Nautical Almanac Circular', No. 20: 'Local Particulars of the Total Eclipse of the Sun, 1914 August 20th-21st'; an Ordnance Survey eclipse map for the 29 June 1927 eclipse; a colour drawing of the total eclipse of 29 June 1927 by V.S. Norbury William; three photographs of the eclipse of 9 May 1929 and three related photographs of the instruments and observing camp; and a pamphlet for the Royal Astronomical Society's eclipse tours to Canada, 1932.