Referee's report by Hugh Longbourne Callendar, on a paper 'The compressibility of gases between one atmosphere and half an atmosphere of pressure' by Robert John Strutt, Lord Rayleigh Sectional Committee: Physics and Chemistry Recommended for publication in Philosophical Transactions, in full. All the illustrations should be reproduced. It is a most interesting completion of a most important piece of work. [Published in Philosophical Transactions A, 1905]. Endorsed on verso as received 3 February 1905. 3 February 1905