Correspondence with Professor Safford, 1894, concerning errors in the 1860 Star Catalogue: north polar distance of 16 Persei.
Letter from G. Dunn concerning 73 Leonis being a variable, 1894.
Letter from S. Newcomb, 1894, concerning the north polar distance of standard stars during 1891-1893, with a reply including the Greenwich observations for 1891.
Correspondence with Major Gore, R.E., concerning the place of double stars, 1894-1895.
Letter from Professor Engstrom concerning BD+35° 2177, 1894.
Correspondence with H. Geelmuyden concerning corrections to the Greenwich Catalogue, 1894.
Letter from J. Glynn concerning an error in the 1891 Greenwich Catalogue, 1894.
Correspondence with Trinity College, Cambridge, concerning the publication of catalogues and with H.H. Turner, Oxford, concerning systematic errors in the Radcliffe observations, 1895.
Correspondence with Paris Observatory concerning discrepancies in the position of Lalande 5857, 1896.
Letter from Sir David Gill at the Cape Observatory concerning errors in the Greenwich and Cape Catalogues, 1901.
Correspondence with S. Newcomb concerning the reduction of Groombridge's observations, 1902.
Letter from Herr Schroeter of Christiana concerning the places of stars in the 12-Year Catalogue, 1902.
Correspondence with the Revd Father Hagen S.J. concerning star positions near the Pole, 1903.
Correspondence with the Chief Astronomer at Ottawa and the Radcliffe Observer, Oxford, concerning star positions, 1904.
Copy of 'Positions Moyennes De 123 étioles Circumpolaires', 1898.
Correspondence with Professor Lewitzky concerning the Dorpat AG Catalogue, 1896-1908.
Internal memoranda on star catalogues, including a list of the agreed zones allocated to each observatory, 1899-1903.
Correspondence with Dr Ristenpart concerning star catalogues and astrographic places, 1901-1906.
Undated listings of stars in the 12-Year Catalogue not observed by Bradley or Flamsteed, 1901-1906.
Undated listings of stars in the 6-Year Catalogue not observed by Flamsteed or Bradley.
Undated listings of stars in the 7-Year Catalogue (1860) not observed by Bradley or Flamsteed.
Undated listings of stars in the 7-Year Catalogue (1864) not observed by Bradley or Flamsteed.
Correspondence with Professor Forbes concerning 11 Vulpuculea, 1880.
Reprint from 'Monthly Notices of the Royal Astronomical Society', Vol. XL, No. 5: 'Systematic Errors of Greenwich North Polar Distance', 1880.
Letter from F.J. Stone, 1880, with a list of right ascensions of 1880 clock stars.
Letter from Airy to Christie, 1880, concerning star ledgers of north polar distances for 1879.
Correspondence concerning fundamental stars, azimuth stars and re-reduction of Lalande's star, 1880.
Correspondence with the United States Naval Observatory concerning altazimuth stars, 1884.
Correspondence with R. Bryant, London Institution, concerning stars observed by him, 1884.
Letter from C. Graves concerning Procyon, 1887.
Letter from W.J. Lynn concerning Theta 1/2 Tauri, 1887.
Letter from B. Weiss concerning fundamental stars, 1889.
Letter from L. de Bull, 1890, with observations of stars.
Correspondence with Mr Romberg, Pulkova, concerning errata in the 10-Year Catalogue, 1890.
Correspondence concerning working catalogue stars for 1887, 1891.
Letter from G. Davidson, California, concerning an error in the 10-Year Catalogue, 1892.
Correspondence with M. Loewy, Paris, concerning the purchase of star ephemerides, 1892.
Letter from H. Jansby, California, concerning observations of 69 Orionis, 1893.
Correspondence with G. Strachan, India Survey, concerning errata in the 9-Year Catalogue, 1893.
Correspondence with Sir D. Gill of the Cape regarding discrepancies between the Cape and Greenwich catalogues, 1893.
Correspondence with Dr Pryer and Pulkova concerning errata in catalogues, 1893.
Undated listing of comparisons with the 'Nautical Almanac', Berlin, and Greenwich placings.