Lees' Method is described at length in the Phil. Trons. An 1898, vol. 191, also in a general way in Poynting and Thompson's "Heat" and Watson's "Textbook of Physics." The modified method is described in detail in "The Measurement of the Heat Conductivity of Sulfur and a Sulfur-Coke Mixture," Physics Thesis by Paul C. Overstreet, State University of Iowa, 1925. This method consists of the measuring of the temperatures of a hot copper disk, U, on one side of a poor heat conducting disk, S, and that of a cooler disk, M, on the other side of S, after the system has come to a steady state - heat being furnished to U as described in Lees' Experiment.
Proceedings of the Iowa Academy of Science
©1926 Iowa Academy of Science, Inc.
Oversheet, Paul C.
"A Modification of Lees' Method for the Determination of the Heat Conductivity of a Poor Heat Conductor,"
Proceedings of the Iowa Academy of Science, 33(1), 241-242.
Available at: https://scholarworks.uni.edu/pias/vol33/iss1/61