THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



AUGUST 1898. 



XIII. Measurement of the Anomalous Changes in the Length 

 and Temperature of Iron and Steel during Recalescen.ee. 



By GUSTAF E. SVEDELIUS *. 



MY experiments and researches have been intended to 

 contribute to our knowledge of the anomalous changes 

 of length in iron and steel while being heated and cooled. 

 I have tried to show in what degree these changes depend 

 upon the percentage of carbon, different conditions of heating 

 and cooling, hardening and annealing, and I am thus able to 

 give some approximate values of the coefficients of expansion 

 of different kinds of iron and steel during the interval of 

 temperature 0°-800°. Besides these linear measurements, I 

 have made a comprehensive series of measurements of tempe- 

 rature, partly to show in what connexion the anomalous length 

 and temperature phenomena stand to each other, and partly 

 to determine .more closely the temperatures at which the 

 former phenomena take place. In these researches I have, 

 for the most part, only been able to confirm the observations 

 already made by others, especially by Prof. Barrett and 

 M. Osmond. It is only in regard to the anomalous length- 

 phenomena which I have found to characterize the tempering 

 of hardened steel, that my researches may offer anything new. 

 Passing by the historical introduction to my work I will 



* Communicated by Prof. G. F. FitzGerald, F.E.S. M. Svedelius 

 published his experiments in Swedish in 1895, hut as the paper is inac- 

 cessible to the majority of English readers the Author, by request, made 

 this summary. 



Phil. Mag. S. 5. Vol. 46. No. 279. Aug. 1898. 



