Reports, correspondence and working papers The folders consist of exchanges with Government Committees and research establishments (mainly R.A.E Farnborough) and with Metropolitan-Vickers (Manhester) re feasibility, manufacture and testing of photo-electric and proximity fuzes. (see letters from H.T. Tizard in D.5 and D.12 about arrangements for Blackett's work on these devices). The material is presented chronologically as far as possible. Blackett's very bulky folders have been split into smaller units for ease of reference. August 1937-August 1940