Referee's report by Thomas Ralph Merton, on a paper 'The production of diffraction gratings II The generation of helical rulings and the preparation of place gratings therefrom' by R G N Hall and L A Sayce Sectional committee: Physics Paper reference code: A150 Recommended for publication in the Proceedings. Merton writes: 'I am familiar with Dr Sayce's work which I consider to be a valuable contribution to this subject'. [Published in Proceedings A, 1952]. Date received not given. 23 August 1952