Copy letter from Edwin Deller, Acting Assistant Secretary of the Royal Society; to Dr JN Pring; the University, Manchester Advises that the President [Sir Joseph John Thomson, PRS] and Council of the Royal Society have granted permission for the reproduction of diagrams illustrating Dr Pring's papers published in the 'Proceedings of the Royal Society' and 'Transactions of the Royal Society' in his book 'The electric arc in chemical industry.' 25 February 1920