The method gives directly, not k, but klc. P. G.
No calorimetric observations are required, but the results are obtained in terms of the thermal capacity of unit volume c, and the measurements give the diffusivity klc, instead of the calorimetric conductivity k.
We thus obtain the simple equation k'(de'/dx') - k"(de"/dx") =c (area between curves)/(T - T'), (4) by means of which the average value of the diffusivity klc can be found for any convenient interval of time, at different seasons of the year, in different states of the soil.
The presence of water in the soil always increased the value of klc, and as it necessarily increased c, the increase of k must have been greater than that of k/c. 13.