Correspondence between H. Spencer Jones and C.A. Jarman, Ministry of Supply, and related papers regarding airborne magnetometers:

1. Memorandum by Jarman on a proposal for a technique and instrument for airborne determination of magnetic elements, c. 1947

2. Confidential memorandum, 1 December 1947, comprised of an extract from the British Supply Office Navigation Section Liaison Letter No. 7, regarding polar navigation.

3. Confidential memorandum on airborne magnetometers, 13 December 1947.

4. Progress report on the research and development of airborne magnetometers, 31 December 1947.

5. Jarman to Spencer Jones, 12 January 1948, regarding the research and development of airborne magnetometers.

6. Spencer Jones to Jarman, 16 January 1948, including formula corrections, with a typescript copy of the letter.

7. Jarman to Spencer Jones, 17 January 1948, replying to no. 6, regarding proposed instrumentation and technique.

8. Jarman to Spencer Jones, 19 January 1948, regarding the research and development of magnetometers.

9. Spencer Jones to Jarman, 26 January 1948, replying to no. 7, regarding proposed instrumentation and technique.