Cork

the spongy outer bark of an evergreen oak. The cork oak grows along the coast of southern Europe and North Africa, but chiefly in Algeria, Spain, and Portugal, to which countries the cork industry is worth several million dollars a year. It is a low, spreading tree with chestnut-like acorns. When the trees are about ten or fifteen years old, the first stripping is made. It is coarse and uneven, and is used chiefly for fishing net floats and similar purposes. The second stripping is better. The quality improves with the age of the tree. Cork harvest comes in July and August. Only the outer bark is removed. Cuts are made around the tree and up and down, dividing the bark into suitable sections. The greatest care is taken not to injure the inner bark by cutting too deeply. The sections are then removed by inserting the flattened handle of the cutter's knife carefully. After scraping the outer surface the sheets are heated and slightly charred to close the pores. They are then flattened in a press and baled for market.

Owing to its toughness, lightness, and elasticity, and the fact that no liquid can pass through it, cork is in demand for bungs of casks, bottle stoppers, bicycle handles, shoe insoles, artificial legs, linings for insect cases, etc. Cork weighs a trifle less than a fourth as much as water. "As light as cork," is a proverbial expression. It is, therefore, an ideal substance for life preservers, buoys, and jackets. The inner bark of the cork tree, like all oak barks, is valuable for tanning. Cork has a peculiar way of dulling a knife edge. Workmen who cut corks by hand whet for each cork. This difficulty is greatly in the way of contriving successful cork-cutting machines; yet but little of the work is now done by hand. Cork chippings and parings ground up with boiled linseed oil make a material which is applied to a coarse canvas in the manufacture of linoleum. Scrap cork is pressed also in damp-proof and insulating boards.

Consul-General Frank D. Hill, of Barcelona, states that exports of cork from Spain during the years 1905, 1906, and 1907 were $6,835,624, $7,626,494, and $8,805,614 respectively. The total importations of cork and manufactures of cork into the United States amounts to about $4,000,000 annually, one-half of which is the bark free of duty; the other half consists chiefly of corks, which pay 15 cents per pound duty. American statistics show yearly imports of about $500,000 worth of cork bark from Spain and over $1,000,000 worth from Portugal, while about $1,500,000 worth of manufactured cork comes from Spain.

See Life Preserver; Bottle