Table 204. 



CONDUCTIVITY FOR HEAT. 



Metals and AII07S. 



The coefficient k is the quantity of heat in therms whicli is transmitted per second ihrouph a plate one centimetre 

 thick per square centimetre of its surface when the difference of temperature between the two faces of the plate 

 is one degree Centigrade. The coefficient k is found to vary with the absolute temperature of the plate, and is ci- 

 pressed approximately by the equation kt — k^ (i -f aJ). In the table *„ 'S the value of kt for o " C, / the tempera- 

 ture Centigrade, and a a constant. 



• .\ repetition of Forbes's experiments by Mitchell, under the direction of Tail, shows the conductivity to increase 

 with rise of temperature. (Trans. R. S. E. vol. :n, 1887.) 



t Herschcl, Lebour, and Dunn (British Association Committee). 



Gmithsonian Tables. 



197 



