Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society to Professor W M Thornton 'I have to acknowledge the receipt of your letter of yesterday returning your second paper with the reference to the first deleted. In the face of my previous letters I cannot understand your reference to re-writing the first paper. The paper was definitely withdrawn by Sir Charles Parsons and was returned to you on loan in order that you might make a copy. The paper must be returned here without any alteration whatever.' 7 August 1915