Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to [Messrs Harrison and Sons, publishers] 'Kindly forward on loan and return to the Assistant Editor, Institution of Petroleum Technologists, 17 Gracechurch Street, E.C.3., the blocks of Figures 74 and 74a from Dixon's paper in the Phil. Trans. Vol. A.200, p.315.' 26 January 1927