Referee's report by Samuel Roslington Milner, on two papers 'Experiments on the exchange of energy between gas, solid, and adsorbed layer in vacuo. —I. A method of detecting variations in the thermal efficiency of molecular collisions' and 'Experiments on the exchange of energy between gas, solid and adsorbed layer in vacno—II. The effect of a deposited monomolecular layer on the efficiency of molecular collisions' by M C Johnson Sectional committee: Proceedings [Physics] Recommended for publication in Proceedings, in full. Both papers should be condensed and some points could be made clearer. [Both papers published in Proceedings of the Royal Society A, 1930]. Endorsed on verso as received 28 April 1930. April 1930