Copy letter from Robert William Frederick Harrison, to W P Devine, 10 Victoria Street, S.W. 'Dear Sir, In reply to your letter of yesterday, Mr Brennan has not communicated any paper to this Society on the subject of his gyroscopic mono-rail vehicle, but merely showed it at the recent Soiree of the Society. If you would like to communicate with him direct his address is, Woodlands, Gillingham, Kent. I am, faithfully yours, Robt [Robert] Harrison Assistant Secretary, R.S. [Royal Society]'. 24 May 1907