Copy letter from Robert William Frederick Harrison, to Professor Hugh Longbourne Callendar, Fellow of the Royal Society Harrison writes concerning the space requirements for Callendar's proposed petrol motor experiments for the Soirée on the 13 May, noting that the width of the doors of the two available rooms on the ground floor are three feet three inches, but that 42 inches are required to save them dismantling the machine. He asks Callendar to write concerning a solution to this difficulty. 22 April 1904