Correspondence file including letters re sending observers from Australia to join the British expedition party; letters re preparations (equipment and maps); letters written from Sumatra describing the observation by the eclipse party; and subsequent letters re the spectra of the eclipse, photographic plates and reports etc. Correspondents include A.C. Crommelin, Walter Geoffrey Duffield, Frederick Stratton, Charles R. Davidson, J.H. Jeans, Nicholas Bosanquet, A.L. Mathewson, Winthrop R. Wright, Arthur Eddington, John A. Miller, A. Fowler and H.F. Newell. Recipients were mainly Dyson and C. Davidson.