“ The outer layer of bark in the cork oak by annual additions from within gradually becomes a thick soft homogeneous mass, possessing those compressible and elastic properties upon which the economic value of the material chiefly depends. The first stripping of cork from young trees takes place when they are from fifteen to twenty years of age. The yield, which is rough, unequal and woody in texture, is called virgin cork, and is useful only as a tanning substance, or for forming rustic work in ferneries, conservatories, &c. ”

“ Its specific lightness, combined with strength and durability, recommend it above all other substances for forming life-buoys, belts and jackets, and in the construction of life-boats and other apparatus for saving from drowning. ”