Referee's report by Hugh Longbourne Callendar, on a paper 'Notes upon evaporation and the discharge of steam from orifices' by W Geoffrey Duffield Sectional Committee: Physics Not recommended for publication in the 'Proceedings of the Royal Society of London'. The experiments are poorly designed and the meaning of the paper unclear. Refers to work of Martin Knudsen. [Not published] Endorsed on verso as received 2 July 1921. [July 1921]