Referee's report by James Walker, on a paper 'The measurement of ionic velocities' by Bertram Dillon Steele Sectional Committee: Physics and Chemistry Recommended for publication in Philosophical Transactions, in full. The illustrations seem to all be necessary for the comprehension of the paper. Although rather carelessly put together in parts, this paper is apparently a record of very careful and valuable work. No change is necessary except some slight alterations which the author will probably make himself in proof. [Published in Philosophical Transactions A, 1901]. Endorsed on verso as received 20 June 1901. June 1901