Paper, 'On the measurement of magnetic properties of iron' by Thomas Gray This paper contains some of the results and a description of the methods employed in a series of experiments on the rate of change of an electric current, immediately after the application or reversal of a constant electromotive force, in a circuit containing the magnetizing coil of a large electromagnet or the primary coil of a transformer. Includes 14 graphs of experimental results, two pages of diagrams of experimental apparatus, and one photographic print of experimental apparatus. Subject: Physics / Chemistry Received 6 April 1894. Read 24 May 1894. Communicated by Lord Kelvin. A version of this paper was published in volume 184 of Philosophical Transactions as 'On the measurement of the magnetic properties of iron'. 1894