Correspondence regarding tides, surveys, longitude determination and purchase of instruments, divided into the following sections:

'Survey of the Cape Colony': correspondence regarding the survey, 1907-1923, comprised mainly of general enquiries from landowners concerning distances.

'Surveys - General': correspondence comprised mainly of requests for the longitudes of various places in Southern Africa and for copies of various Survey publications, 1907-1923.

'Trigonometrical Survey', 1921-1923.

'Surveyor General, Cape Town', 1907-1923.

'Observations given': correspondence regarding the transmission of time signals for various surveys, requests for information on surveys, and results, 1907-1923.

'Longitude of Ascension': correspondence on the determination of the longitude of Ascension Island, 1907-1923.

'Instruments & Tradesmen': correspondence concerning the purchase and installation of various survey and tidal instruments, 1907-1923.

'Miscellaneous', 1907-1923.

'Tides', 1907-1923.

'General Colonial Correspondence. Cape Ministers & Officers'.

'General Colonial Correspondence. Miscellaneous'.

'General Colonial Correspondence. Harbour Board', 1907-1923.

'General Colonial Correspondence. Railway Department', 1907-1923.