Letter to Sir Ben Lockspeiser, to accompany Blackett's application to Department of Scientific and Industrial Research for three substantial research grants 'to support the study of rock magnetism' by himself and SK Runcorn. 'As the subject and possibilites of rock magnetism are not very well known in this country, I have thought it fit to attempt to give a short outline of its history, and of possibilities which may result from further work'. The succeeding 'Notes' review current work throughout the world, the contribution of various researcheers (many of whom supplied specimens, data or other information to Blackett, and corresponded with him), existing hypotheses especially on field reversal, Blackett's attempts to initiate co-operative projects on an international level (especially in South Africa and with Bhabha's Institute at Bombay), the importance of the project, and Blackett's belief that at that time 'this country has, largely through the operation of various accidental causes, taken over the lead in the application of rock magnetism to geophysical problems'. 3 May 1954