|Description||Blackett kept his correspondence on rock magnetism in roughly chronological order, in very bulky folders, separate from his other letters. The original bulky folders have been split into more manageable proportions, but the chronological order has been retained once it reveals the development of his ideas through his own and others' researches, and the urgency with which he pressed on a project which interested him. Sometimes Blackett would remove material of special interest or relevance and interfile it with the related datasheets or working papers; such letters have been left in place, and a note made on the relevant items in earlier entries. Blackett also kept in a special folder correspondence specifically related to his major paper on climatology (R.S. 88): see C.114-123.|
In the folders, extensive correspondence with an individual has been kept together with terminal dates and some indication of content. (See especially the entries for J.M. Ade-Hall, E.C. Bullard, S.K. Runcorn, R.L. Wilson). With these exceptions, the material is presented chronologically, thus enabling the development of Blackett's thinking, and the peaks of his activity in the field of research, to be followed.
The correspondence is particularly heavy for 1964-1966, when Blackett was actively pursuing the research for the unpublished paper of 1967. During this period he was in constant touch with colleagues, requesting samples, discussing results, methods and equipment, preparing papers and the like; there is also a small amount of administrative correspondence about grants, degrees, appointments, etc. for his research students.
The ensuing decline of Blackett's active research is also reflected in the correspondence. His last letter to C.W.F. Everitt, February 1974, is very interesting in this respect (C.268)
A brief indication is given in the catalogues entries of any material of particular scientific or personal interest.
Note: Additional correspondence on rock magnetism appears in C.81-82, C.98-100, C.105, C.114-123, and passim among the related working papers.