Copy letter from Robert William Frederick Harrison to The Director, National Physical Laboratory, Bushy House, Teddington 'Dear Sir, In reply to your letter of January 19th, asking for permission to reprint a paper of Messrs Mather and Smith on a "Comparison of the Board of Trade Ampere Standard Balance", I have to say that there will be no objection on the part of the Royal Society provided due acknowledgement is made of the source from which the paper is reprinted. I understand that the type from which the paper was originally printed has been distributed so that, is that case, the paper will require to be re-set at your expense.' 21 January 1909