Letter from [William Fletcher] Barrett, 6 De Vesci Terrace, Kingstown, Co Dublin, to Mr [Robert] Harrison, [Royal Society] Informs that Dr Muirhead, who had charge of Sir James McKenzie Davidson's certificate, has informed him that his ill health prevents him taking up the task of preparing a new certificate. Asks if the old certificate may be re-hung with a new supplementary certificate. 1 December 1913