Correspondence of 1903-1904 concerning the St Louis Exhibition of 1904, including a request from the Royal Commission for an exhibit to be sent, a list of exhibits, a written description of the Royal Observatory photographs and the work of the Royal Observatory generally, correspondence with the Royal Photographic Society, correspondence on the award of the Grand Prize to the Royal Observatory exhibit, a file of miscellaneous memoranda, and diagrams of exhibition frames.

Correspondence concerning the Franco-British Exhibition of 1908 in relation to the 'Various Industries Section'.

Correspondence of 1909-1910 concerning the Brussels Exhibition of 1910, including lists of photographs to be sent, correspondence on the cost of transport to Brussels, and correspondence with 'La Revere Moderne' concerning an article on the Brussels exhibition.

Correspondence of 1909-1910 relating to the Japan-British Exhibition of 1910, including the prospectus, a plan of the White City exhibition area, correspondence concerning the Royal Observatory exhibit in the science section of the exhibition, and correspondence concerning the hydrographic section and the exhibit of chronometers.

Correspondence concerning the Coronation Exhibition of 1911, including a request for exhibits, a letter from the Admiralty informing the Royal Observatory that there is not to be a naval exhibit, a list of Royal Observatory exhibits, and enquiries about missing charts following the close of the exhibition.