Referee's report by Charles Herbert Lees, on a paper 'Determinations of the fundamental standards of length in terms of wave-lengths of light' by J E Sears, Junr. and H Barrell Sectional Committee: Physics Recommended for publication in the 'Philosophical Transactions of the Royal Society'. Suggests the authors re-examine their assumptions about the refraction index of air at different temperatures and pressures. Refers to work of Posejpal and Schacherl. [Published in the Philosophical Transactions of the Royal Society A, 1934] Endorsed on verso as received 15 December 1933. [December 1933]