Discussion: “An Investigation of the Variation in Heat Absorption in a Pulverized-Coal-Fired Water-Cooled Steam-Boiler Furnace” (Schueler, L. B., Reid, W. T., Cohen, Paul, Corey, R. C., Mumford, A. R., Humphreys, C. G. R., and Bice, G. W., 1948, Trans. ASME, 70, pp. 553–614)