Referee's report by Thomas Ralph Merton, on a paper 'The production of diffraction gratings; the copying of plane gratings' by G D Dew and L A Sayce Sectional committee: Physics Paper reference code: A12 Recommended for publication in the Proceedings. Merton writes: 'I am familiar with Dr Dayce's work. He has shown great skill in overcoming formidable experimental difficulties, there is already a demand for gratings made by the methods described at the N.P.L. I hope that the paper will be published in full.' [Published in Proceedings A, 1951]. Date received not given. 25 January 1951