Correspondence regarding admissions to visit the Royal Observatory. The volume is divided broadly into requests from the Admiralty to visit the Royal Observatory, introductions on behalf of visitors, personal requests to visit the Observatory, questionnaires for visitors, and instructions to assistants to receive visitors. The correspondents include J. Washington, J. Field, W.H. Sykes, J.W. Lubbock, B.A. Gould, J.C. Adams, J.R. Hind, J.E. Grey, J.A. Brown, J.D. Forbes, R. Fitzroy, J. Challis, W. Spottiswoode, J. Lee, Lord Wrottesley, G. Everest, O.M. Mitchel, P.A. Secchi, J.T.R. Robinson, J.B. Pentland, L.A. Quetelet, A.A. de la Rive, A.D. Bache, C.V. Walker, J. Glaisher, C.T. Bright, W. Huggins, C.B. Vignoles, W.H. Smyth, C. Pritchard, E. Dunkin, W. De La Rue, D.T. Ansted, R.W. Thomson, J.S. Pakington, R.M. Bromley, J. Jones, F. Madden, J.W. Cunningham, J.P. Gassiot, J. Penn and T. Hankey.