Copy letter from Robert William Frederick Harrison to Harrison & Sons 'Will you please prepare electros of the following blocks illustrating the paper by H L Callendar and W E Dalby "On the measurement of temperature in the cylinder of a gas engine" 9Proceedings A, vol 80, pp54-74);- Fig 1 (p59): Figs 2, 3, & 4 (p 60): Fig 5 (p62): Fig 6(p63) and Fig 10 (p72). I will send you, later on, the address to which the electros, with your account, are to be delivered.' 24 February 1908