Referee's report by Kathleen Yardley Lonsdale, on a paper 'Neutron diffraction' by G E Bacon and J Thewlis Sectional Committee: Physics Recommended for publication in the 'Proceedings of the Royal Society of London'. The paper has a wide interest, including for nuclear physicists, than would be available if published in the Acta Crystallographica. Suggests adding formulae where necessary, to aid clarification. A paper by Ernest Omar Wollan and Clifford Glenwood Shull, referred to as 'forthcoming', has been published in the Physical Review. Reference should be made to a paper by Clifford Glenwood Shull, Ernest Omar Wollan, George A Morton and W L Davidson, also published in the Physical Review. Comments on the formulae and symbols. [Published in the 'Proceedings of the Royal Society of London'] No received date. [1948]