Brashness, internal stresses, and hidden checks produced by poor drying may be passed undiscovered in the most rigid inspection, since they cannot always be determined by direct examination of the material. The drying process itself is, therefore, of prime importance, not only for the saving of material through the avoidance of due waste from injuries, in drying but even more so for the assurance that the material which passes inspection shall be free from subtle defect or possible weakness.