Letter and observations from Captain W.J. Wharton regarding the results of his experiment to find the longitude of Malta from Gibraltar, 1873.
Printed paper on the galvanic determination of the difference in longitude between Bombay and Malta, 1874.
Newspaper cutting from the 'South Australian Advertiser', 19 February 1889, regarding Australian longitudes.
Correspondence on marking Major Darwin's longitude station at Singapore, 1891-1892.
Miscellaneous correspondence comprised mainly of requests for longitudes, 1889-1892.
Information supplied to Lloyd's for the 'Seaman's Almanac', including a list of the length of a degree of longitude in different latitudes, 1889-1893.
Correspondence with Sir Charles Wilson and Captain Grant regarding the Mashonaland boundary, 1897.
Letter from the Surveyor General of Brisbane regarding the difference in longitude between Brisbane and Sydney, 1892.
Correspondence on changing the longitude of Indian maps due to the re-determined longitude of Madras, 1892.
A copy, in French, of the resolutions of the International Geographical Congress at Berne, 1891.
Lists of arcs of longitude determined, forming the chain from Suez to Madras, 1892.
Notes regarding the chain of stations used to re-determine the longitude of Madras, 1892.
Correspondence between Christie and J.T. Walker regarding the longitude of Madras, 1892.
Correspondence with various people regarding longitudes, 1893-1903, including letters from A. Auwers, Foerecter and others concerning the Madras longitude.
Copies of a 'Time Dial for the Whole World', produced by J.C. Sellars, 1898.
Paper for the Board of Trade examinations, 1901.