Correspondence with the Astronomer Royal regarding work at the Royal Observatory, Cape of Good Hope, including the following material:

Correspondence between Sir Harold Spencer Jones, Astronomer Royal, and John Jackson, His Majesty's Astronomer, Cape Observatory, regarding the Coleman 8-inch Cooke Refractor, 1948.

Correspondence between H. Spencer Jones and J. Jackson regarding solar photographs, standard frequency transmissions, the war bonus, the end of the war in Europe, rhythmic signals and pendulum clocks, 1945.

Correspondence between H. Spencer Jones and J. Jackson regarding the death of Mrs Mullis, bomb damage in the south-east of England, Shortt clocks, quartz clocks, Radcliffe Observatory mirrors and blast damage to the Greenwich Observatory, 1944.

Memorandum from the Chief Assistant at the Cape Observatory to J. Jackson regarding sun plates, with an attached list of sun plates, 1944.

Correspondence between H. Spencer Jones and Jackson regarding the Knox-Shaw mirror, 1944.

Correspondence between H. Spencer Jones and J. Jackson regarding time signals, the Yate Telescope, Shortt clocks, the awarding of the Royal Astronomical Society's Gold Medal to J. Jackson, chronometers and watches, 1943.

Correspondence between H. Spencer Jones and J. Jackson regarding the insertion of spectral types in the Cape catalogue of the proper motions of faint stars, 1937.