Paper, 'Electrical resistance of iron at a high temperature' by J [John] Hopkinson

Description

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'.

Reference number

PP/13/29

Earliest possible date

1889

Physical description

Ink and graphite pencil on paper

Page extent

2 pages

Format

Typescript
Diagram