Letter from W J [William John] Johnston, 26 St John Street, Oxford, to [Joseph] Larmor He is ashamed to trouble Larmor with mathematical work, but in trying for a simple account of tensors it was 'no more than the pursuit of a mare's nest'. He has found simple expressions for three Christoffel symbols and the Riemann-Christoffel tensor, which he discusses, noting a suggestion of Larmor's. Professor Macaulay's papers in the Proceedings of the Royal Society seem complicated and difficult. Johnston's idea is for the publication of a book of 100 pages; his lectures on quaternions were taken down by a student, which he intends to rewrite, with some pages on Clifford's algebra. He wishes to send the manuscript of a short book on tensors and asks for a postcard directing him on where to send it. 19 September 1923