TESTING COKE OVEN REFRACTORIES 1

General Reluirements are stated for mat, bench walls, checker work, regenerator korbels, main flues, division walls, oven chambers and jamb blocks. The following Tests are described:—inspection, reheating tests on three qualities, bending test. Requirements and specifications are discussed. The latter part ofthe paper deals with Apparent density and Permanent expansion. It is shown that the relation between them is a linear one and a chart is given. The average of thirty‐nine determinations gives an apparent density, for Western brick, 0.016 higher than for Pennsylvania brick, due to the fact that the Western ganister is slower to transform than the Eastern.