CHAR′RING (Surface)

The operation by which the surface of wood is carbonised, to prevent its decay from exposure to air and moisture. Stakes and piles are generally thus treated before they are driven into the ground. Casks are charred on the inside by coopers when they are intended to hold water. In both these cases the fire is commonly applied directly to the wood. A new method has, however, been lately employed with apparent succe . This consists in washing the wood with the strongest oil of vitriol. In this way not only the outer surface, but the surface of all the cracks and holes, get carbonised, which is not the case when heat is employed. It succeeds admirably with musty casks and vats.