Referee's report by Olaus Magnus Friedrich Erdmann Henrici, on a paper 'Quaternions and projective geometry' by Charles Jasper Joly Sectional Committee: Mathematics Recommended for publication in Philosophical Transactions, in full and he has no modifications to suggest. The paper is of considerable interest. It connects the theory of Quaternions with a number of other branches of Mathematics and thus lifts it out of the somewhat isolated position which it hitherto occupied, and it largely extends the scope of its applications, The paper thought long, is written in a very concise style. [Published in Philosophical Transactions A, 1903]. Endorsed on verso as received 18 December 1902. December 1902