Copy letter from Robert William Frederick Harrison, to General Sir Neville Gerald Lyttelton 'Dear Sir, At the request of the President of the Society, Mr Brennan has consented to give a demonstration of his mono-rail invention here at 4 o'clock in the afternoon of Wednesday, the 19th inst. [instant] and I am directed to offer you that opportunity of seeing the demonstration. An invitation to the evening Soiree has been sent to you under separate cover. I am, faithfully yours, Robt [Robert] Harrison Assistant Secretary, R.S. [Royal Society]'. 14 June 1907