Copy letter from Robert William Frederick Harrison to Professor H [Hugh] L [Longbourne] Callendar FRS 'In response to your request of the 20th instant I have no sent back to you your paper on The Specific Heat of Water, together with its diagrams. I had the authority of the Physics and Chemistry Committee for doing this, and I am to ask you, if you find it necessary to make any material alteration in the paper, either to date the alterations, or , if it should be equally consonant with your wishes, to treat the date of its return here as the date of receiving the paper. Either plan will meet official requirements.' 26 January 1912