None of the material is dated, though W.H. McCrea ( Obituary Notices ... 1950-51, p. 435) describes Milne's work on 'kinematic relativity' as "his predominant scientific interest from 1932 onwards". MS. Eng. misc. b. 426/C.52 is a draft for a paper apparently intended for publication; MS. Eng. misc. b. 426/C.53 - MS. Eng. misc. b. 426/C.57 are sequences of notes and problems, probably for lectures.