Correspondence entitled 'Cape Observatory and Survey 1845 to 1848. Printing 1839-1848', divided into ten sections:

'Fallows's Observations and Henderson's Observations': correspondence between G.B. Airy, T. Maclear and the Admiralty, including a list compiled by C.P. Smyth of Henderson's Cape manuscripts, dated 24 July 1847.

Papers relating to assistants at the Cape Observatory, 1846.

'Instruments for the Cape Observatory': correspondence, 6 March 1846 - 19 April 1848, concerned mainly with the delivery of the Cape Equatorial from Munich.

'Correspondence, tabulated triangulation and report to a Committee of Government on the Cape Survey', including details of the Arc of the Meridian Observations, with a diagram and a line drawing of the work being done.

'Correspondence about returning Zenith Sector to Greenwich': correspondence between G.B. Airy and T. Maclear.

'Position of Lacaille's Stations': a printed article by T. Maclear, corrected by G.B. Airy, on the verification and extension of Lacaille's Arc of Meridian, including detailed maps and diagrams.

'Verification of the Astronomical Amplitude of Lacaille's Arc...Description of Bradley's Sector, with which the Astronomical Observations of Mr Maclear were made', written by G.B. Airy, and including tables of observations.

Correspondence regarding the printing of T. Maclear's work 'Account of Observations made at the Cape of Good Hope with Bradley's Zenith Sector', with drawings of the Ordnance Survey Base Apparatus.

'Computations of decimal point in the coefficient of Mr Maclear's equations respecting Lacaille's Arc.'

Correspondence regarding publication of Maclear's observations, January 1843 - February 1844.