Referee's report by Douglas Rayner Hartree, on a paper 'Oblique propagation of electromagnetic waves in a slowly-varying non-isotropic medium' by H G Booker Sectional Committee: Physics Recommended for publication in the 'Proceedings of the Royal Society of London'. 'I consider this paper an unusually able piece of work'. [Published in the 'Proceedings of the Royal Society of London'] Endorsed on verso as received 7 February 1936. [February 1936]