The contribution of radiation to the conduction of heat

Measurements of the thermal conductivity by stationary and non-stationary methods are liable to give different results, in particular at high temperature. The cause of this discrepancy can be found in a contribution of radiation to the conduction of heat. Instead of Fourier’s differential equation we get an integro-differential equation and an integral equation. Solutions are given for the steady state, for the source functions and for problems which can be solved by separation of variables. Some applications are also given.