Referee's report by Robert Bellamy Clifton, on a paper 'New determination of the mechanical equivalent of heat' by James Prescott Joule Recommended for publication in the 'Philosophical Transactions of the Royal Society'. Has not had time to write a full review, but has fully read the paper. The paper is a continuation of an earlier one by the same author published in the Philosophical Transactions. Refers to work of Henri Victor Regnault. Suggests omitting a section which may have been included in error. Subject: Physics and Chemistry [Published in the Philosophical Transactions of the Royal Society, 1878] 10 April 1878