Table 223. 

 CONDUCTIVITY FOR HEAT. 



205 



The coefficient k is the quantity of heat in small calories which is transmitted per second through 

 a plate one centimeter thick per square centimeter of its surface when the difference of tempera- 

 ture 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 expressed approximately by the equation 

 kt = ko [i + o (/ — /q)]- '^'o 's tlie resistance at /q, the lower temperature of the bracketed pairs 

 in the table, kt that at temperature t and a is a constant. 



* Jaeger and Diesselhorst. 

 Smithsonian Tables. 



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



