Raymond Osborne, age 13, of Niagara Falls, Ont., Canada, for his question:
WHAT IS CORK?
What a wonderful product cork is. It is used for insulation and the soles of some shoes. It can be used for floor and wall coverings and also for bulletin boards at home and at school. Where would some bottles be without cork stoppers? And did you know the product is also used as the center in some baseballs? It's also vital for fishing net floats and fishing pole handles.
Cork comes from a type of oak that is evergreen the year around. It grows especially well in Spainand Portugal, and it is here that most of the world's cork is grown. The third best location for growing cork trees is Algeria, with California and some of the southeastern states coming up.
The outer layer of the cork oak tree is made up of dead cells. The walls become thickened and waxy and the cells are so compact that each may be touching 14 other cells. Cork trees live from 300 to 400 years and grow to heights of about 50 feet.
Cork is harvested just as many other crops are. A cork tree must reach the age of about 20 before it will have bark that is thick enough to be stripped. A first removal of cork from a tree is called the virgin bark. It is removed in June, July or August. After cork has been removed from the tree, it is necessary to wait another 10 years before the tree can be stripped again. The tree's best cork is produced after the second stripping.
Long handled hatchets are used to cut long, oblong sections of bark from the top of the lowest branches to the bottom of the tree. Sections of cork bark are then pried off very carefully with the wedge shaped handles of the hatchets.
The inner layer, called the periderm, produces more cork after each stripping. Cork will not grow on a spot where the inner layer of the bark has been cut by the stripper's hatchet, however.
Large slabs of cork are boiled, dissolving the tannic acid from the cork and softening it so that it can be straightened out and packed in bundles. The rough, gritty outer layer is also scraped off. Before being packed for shipment, cork is sorted out according to thickness and quality.
The cork oak tree actually belongs to the beech family, Fagaceae. It is of the genus Quercus and the species suber.
Cork is also the name of the second largest city in the Republic of Ireland. The city was started by Viking settlers in 800 A.D., although Saint Finbar, an Irish bishop, founded a church there in about 600 A.D.