Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Dr. [Frank] Horton; Royal Holloway College, Englefield Green Refers to a paper by [Frank] Horton and Ann [Catherine] Davies, 'The ionizing power of the positive ions from a glowing tantalum film'. Informs Dr. [Frank] Horton that the paper is currently estimated to print at around thirty pages, and asks if he can reduce it to no more than twenty four pages. 5 November 1918