Paper, 'Electrical resistance of iron at a high temperature' by J [John] Hopkinson Hopkinson writes: 'Auerbach, Callendar, and I think also Tait, have observed that the temperature coefficient of electrical resistance of iron is abnormally high. So far as I know no one has pushed his observations to the temperature at which iron ceases to be magnetic. The accompanying curve [see PP/13/29/2] shows the results of experiments made upon a very soft iron wire. The abscissae are the temperatures as estimated by the resistance of a copper wire, the ordinates represent the resistance of the iron wire having unit resistance at 20 degrees Celsius.' Annotations in pencil and ink. Includes a graph of experimental results. Subject: Electricity / Metallurgy Received 14 March 1889. Read 21 March 1889. A version of this paper was published in volume 45 of the Proceedings of the Royal Society as 'Electrical resistance of iron at a high temperature'. 1889