| RefNo | PP/16/33 |
| Previous numbers | PP/48/33 |
| Level | File |
| Title | Paper, 'Magnetism and recalescence' by John Hopkinson |
| Date | 1890 |
| Description | Hopkinson writes: 'In my experiments the results of which are published "Phil. Trans." 1889 A p. 443 I showed that recalescence and the disappearance of magnetisability in iron and steel occurred at about the same temperature. The evidence I then gave was sufficiently satisfactory, but did not amount to absolute proof of the identity of the temperatures. Osmond has shown that the temperature of recalescence depends upon the temperature to which the iron has been heated, also that it differs when the iron is heated and when it is cooled. He also showed that for some sorts of steel the heat is liberated at more than one temperature, notably that in steel with 0·29 per cent, of carbon heat is liberated when cooling at 720°C. and at 660°C., and that with steel with 0·32 per cent, carbon there is a considerable liberation of heat before the temperature is reached when this becomes a maximum.'
Annotations in pencil and ink. Includes three pages of diagrams of experimental apparatus and results.
Subject: Physics
Received 9 October 1890. Read 20 November 1890.
A version of this paper was published in volume 48 of the Proceedings of the Royal Society as 'Magnetism and recalescence'. |
| Extent | 7p |
| Format | Typescript |
| Diagram |
| PhysicalDescription | Ink and graphite pencil on paper |
| Digital images | View item on Science in the Making |
| AccessStatus | Open |
| RelatedMaterial | DOI: 10.1098/rsta.1889.0014 |
| DOI: 10.1098/rspl.1890.0050 |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA8063 | Hopkinson; John (1849 - 1898); electrical engineer | 1849 - 1898 |