Referee's report by James Clerk Maxwell, on a paper 'On the mathematical theory of stream-lines, especially those with four foci and upwards' by William John Macquorn Rankine Recommended for publication in Philosophical Transactions, as it 'may prove useful in deducing general principles from the data of experiment and observation and in suggesting plans for further reserved'. Subject: Physics [Published in Philosophical Transactions, 1871]. 2 March 1870