Referee's report by Douglas Rayner Hartree, on a paper 'On the relation between the form, force constants, and vibration frequencies of triatomic systems' by William George Penney and Gordon Brims Black Mcivor Sutherland Sectional committee: Mathematics Recommended for publication in Proceedings, in full. Lists modifications that should be made. Includes letter [dated 25 May 1936] stating that the authors have met the referee's wishes. [Published in Proceedings of the Royal Society A, 1936]. Endorsed on verso as received 7 May 1936. May 1936