Letter from C N Haden & Sons, Engineers & Founders, 123 Cromer Street, London, to [Robert William Frederick] Harrison, The Royal Society, Burlington House 'Dear Sir, Your esteemed letter to hand. We will send one of our foreman to examine the apparatus and ascertain the cause of defects to which you refer, and at the same time will see you with reference to the boiler. Yours respectfully, C.N.Haden & Sons'. 4 December 1907