Almost all this work is in manuscript, and a substantial part of it remains in Bullard's original folders bearing his descriptions and dates, which are quoted in inverted commas in the catalogue entries. The policy of retaining the original arrangements of the folders has been followed even when only one or two sheets of paper were contained; D.143 and D.293 contain folders now empty from which material had been removed or redistributed by Bullard in ways not now easily traceable. Very bulky folders, and a fortiori, the large filing-drawer dividers Bullard sometimes used to hold his more extensive accumulations of material, have been split into more manageable units for ease of reference.
Much of the early work on gravity measurement and explosion seiesmology, conducted from the Cambridge Department of Geodesy and Geophysics, includes correspondence with or to the ten Reader, Sir Gerald Lenox-Conyngham, and other members of the Department. In conjunction with Section B it thus forms a useful contribution to the history of the subject and the Department.
To a condsiderably less extent, some of the work on geomagnetism conducted when Bullard was Director of the National Physical Laboratory includes material relating to staff and activities there.
The topics are presented in chronological order of the earliest documented evidence of Bullard's involvment