Referee's report by Horace Lamb, on a paper 'Primary and secondary vortices in oscillating fluids: their connection with skin friction' by (the late) H Ayrton Sectional committee: Mathematics Recommended for publication in Proceedings. If the paper was written by a living author, the referee would suggest returning the paper to them for modification. Since this is impossible, the paper should be published as it stands. [Published in Proceedings of the Royal Society A, 1926]. Endorsed on verso as received 27 April 1926. April 1926