Copy letter from Robert William Frederick Harrison, to Joseph Ernest Petavel, [Fellow of the Royal Society], The Victoria University, Manchester The Society has received an application from the editor of the 'Zeitschrift für das gesamte Schiess und Sprengstoffwesen' for electros of blocks illustrating Petavel's paper on 'The Pressure of Explosions, Experiments on Solid and Gaseous Explosives'. Asks if Petavel has any objection to the Editor having these at his own expense. 15 June 1906