turned into finished form. [Illustration: Pile of Bark in the Forest] [Illustration: Weighing Bark in the Forest] The cork oak, known botanically as _Quercus suber_, attains a height of from twenty to sixty feet and measures sometimes as much as four feet in diameter. Its wide-spreading branches are rather closely covered with small evergreen leaves, thick, glossy, slightly serrated, and downy underneath. In April or May flowers of a yellowish color appear, succeeded by acorns which ripen and fall to the ground in the late fall. Pliny evidently knew whereof he wrote, for the cork oak’s acorns are bitter and not at all pleasant to the taste. They form, however, one of the forests’ chief sources of revenue, since, fed to swine, they give a peculiarly piquant flavor to the meat, Spanish mountain hams being noted for their excellence. Unfortunately, the herds in foraging for food destroy the young trees and thus do serious and permanent injury by preventing new growth. [Illustration: Virgin Cork and Second Stripping Bark] [Illustration: Cork Bark, “Back” and “Belly”] The “corkwood,” or cork of commerce, is the outer bark of the cork oak. When it has attained a diameter of approximately five inches, or, to be more exact, measures forty centimeters in circumference according to the Spanish governmental regulations, which the tree does usually by the time it is twenty years old, the virgin cork, as the first stripping of bark is called, is removed. This virgin cork is so rough, coarse, and dense in texture that it is of very little commercial value. Fortunately its removal does not kill the tree, but, on the other hand, seems to promote further development, for the inner bark--the seat of the growing processes--undertakes at once the formation of a new covering of finer texture. Each year this, the real skin, with its life-giving sap, forms two layers of cells--one within, increasing the diameter of the trunk; the other without, adding thickness to the sheathing of bark. After eight or ten years this is also removed, and, while more valuable than the virgin cork, it is not as fine in quality as that of the third and subsequent strippings, which follow at regular intervals of about nine years. At the age of about forty years the oak begins to yield its best bark, continuing productive as a rule for almost a century, although cork trees several hundred years old are not unknown. Flourishing as it does in a hot, semi-arid climate, there seems to be no reason why this valuable tree should not be successfully introduced in the southern and southwestern sections of the United States; in fact, in the year 1858 the United States Government took certain steps in this direction, and even went so far as to distribute seedlings to interested persons in several states. The Civil War interfered, however, and the experiments were never fully carried out. [Illustration: Preparing Bark for Carriage to the Boiling Station] [Illustration: