THE 



LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



DECEMBER 1855. 



LIIL On the Transmission of Heat in Metals. 

 By G.Wiedemann*. 



1. Conductibility of Zinc. 



AN investigatiou undertaken by myself and Dr. Franz showed 

 that the values of the relative conductibility of different 

 metals for heat and electricity were very nearly equal t- 



With the same apparatus which served for the earlier experi- 

 ments, I have recently undertaken a determination of the con- 

 ductibility of zinc for heat. 



A zinc wire, 4'4 millims. thick, was used ; its surface was very 

 carefully polished, but not silvered. The wire was investigated 

 in air. Its temperatures were taken at points, which followed 

 each other at distances of 2 inches from the warmest part of 

 the mre (the zero point) to the coldest, and in degrees of the 

 galvanometer described in the above paper, were as follows : — 



The numbers in the column x are the distances from the zero 

 to the several points on the bar at which the tempei'aturcs were 



* From PoggendorfF's Annalen, vol. xcv. p. 3.37- 



t PoggendorfTs ^nnaZen, vol. lxxxi.\. p. 497; and Phil. Mag. vol. vii. p. 33. 

 Phil Mag. S. 4. Vol. 10. No. 68. Dec. 1855. 2 D 



