Building Material [2]
71) The thin radial fibres extending from the pith to the cambium layer is called medullary rays.
72) The inner annular rings surrounding the central portion or core of a tree is
73) The defect in timber caused due to over-maturity and unventilated storage of the wood during its transit, is called
74) The defect in timber caused by imperfect seasoning, is called
75) Seasoning of timber