Referee's report by Hugh Longbourne Callendar, on a paper 'Explosions of coal-gas and air' by Bertram Hopkinson Sectional Committee: Physics and Chemistry Recommended for publication in the 'Proceedings of the Royal Society of London'. Suggests another diagram of the top of the apparatus. Reviewer believes the paper could have been done better, and disagrees with many of the methods and conclusions, 'but that is no reason why it should not be published'. [Published in the 'Proceedings of the Royal Society of London'] Endorsed on verso as received 7 February 1907. [February 1906]