Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Messrs. E. Arnold and Co., 41 Maddox Street, W1 Informs E. Arnold and Co that [John Norman] Collie has no objections to them reproducing the diagram found in his article ['The homogeneity of helium and of argon'] for the book [The discovery of the rare gases] by [Morris William] Travers. 18 June 1928