Referee's report by Richard Tetley Glazebrook on a paper, 'A wave-length comparator for standards of length: An instrument for fine measurement in wave-lengths of light. - With an appendix on the use of wave-length rulings as defining lines on standards of length' by Alfred Edwin Howard Tutton Sectional committee: Physics and chemistry Recommended for publication in Philosophical Transactions, with modifications. [Published in Philosophical Transactions A, 1911]. Endorsed on verso as received 17 July 1909. July 1909