Copy letter from Robert William Frederick Harrison to C [Charles] T [Thomas] Heycock FRS 'May I remind you that the paper by Rosenbein & Preshbutt, "The constitution of the alloys of aluminium and zinc!, referred to you for your opinion on March 24, is still in your hands? I should be much obliged if you would return it, with your remarks, at your earliest convenience.' 25 April 1911