Referee's report by Hugh Longbourne Callendar, on the Bakerian Lecture 'The specific heat of metals and the relation of specific heat to atomic weight. (with an addendum by Prof. Perry)' by Professor William Augustus Tilden Sectional committee: Physics and chemistry Recommended for publication in Philosophical Transactions in full without modification and including all the illustrations. The paper is a very valuable contribution to a difficult subject. It is rather short for the Transactions and might be more handy and accessible in the 'Proceedings. [Published in Philosophical Transactions A, 1900]. Endorsed on verso as received 26 February 1900. February 1900