Referee's report by William Henry Bragg, on a paper 'X-ray analysis of the crystal-structure of rutile and cassiterite' by C M Williams Sectional Committee: Physics and Chemistry Recommended for publication in the 'Proceedings of the Royal Society of London'. [Published in the 'Proceedings of the Royal Society of London' A, 1917] Endorsed on verso as received 16 April 1917. [April 1917]