Referee's report by Charles Galton Darwin, on a paper 'The theory of the structure of ethylene and a note on the structure of ethane' by William George Penney Sectional committee: Physics Recommended for publication in Proceedings. He is not familiar with the details of the theory and finds it hard to follow. Some points should be amplified to make the paper more understandable. The ethane part could be made into its own separate paper. The work is very valuable, which is confirmed by the fact that [John Hasbrouck] Van Vleck has sponsored it. [Published in Proceedings of the Royal Society A, 1934]. Endorsed on verso as received 16 November 1933. November 1933