Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Professor [Henry] Briggs; Heriot Watt College, Edinburgh Acknowledges receipt of Professor [Henry] Briggs' revised paper, 'The adsorption of gas by charcoal, silica and other substances'. Notes, however, that it has not been condensed by the amount specified previously and asks Professor Briggs if he would like the manuscript back to amend this. 8 June 1921