Referee's report by Hugh Longbourne Callendar, on a paper 'Researches on explosives.—Part IV' by Andrew Nobel Sectional Committee: Physics and Chemistry Recommended for publication in the 'Philosophical Transactions of the Royal Society'. The author himself admits that some of the conclusions are open to criticism. [Published in the Philosophical Transactions of the Royal Society] Endorsed on verso as received 19 July 1906. [July 1906]