Referee's report by Charles Herbert Lees, on a paper 'The variation with temperature of the thermal con­ductivity and the X-ray structure of some micas I—The thermal conductivity up to 600° C' by R W Powell and Ezer Griffiths Sectional committee: Physics Recommended for publication in Proceedings, in full. Some points should be made clearer before publication, such as the temperature of the glowrays and the heat conductivity of the glowrays. [Published in Proceedings of the Royal Society A, 1937]. Endorsed on verso as received 1 September 1937 August 1937