Referee's report by Harold Jeffreys, on a paper 'On the criterion for stability of a layer of viscous fluid heated from below' by A R Low Sectional Committee: Mathematics Recommended for publication in the 'Proceedings of the Royal Society of London'. Refers to work of Bunt [?] and Robert John Strutt, 4th Baron Rayleigh. Suggests some changes to terminology, and revising some passages, to improve understanding and clarity. [Published in the 'Proceedings of the Royal Society of London' A, 1929] Endorsed on verso as received 4 June 1929. [June 1929]