Every child who reads this book knows that leather is made from the skins of animals. We cannot, of course, call any piece of skin "leather;" it must be carefully prepared before we can give it that name.

When the skin is stripped off the dead animal, it is still covered with hair on the outside, while on the inside there are many bits of fat and flesh. If nothing is done to preservethe skin, it soon begins to rot, and in a week or two it becomes quite decayed. If the skin is salted and dried, it will keep quite well, but it will become as hard and stiff as a board.

What the man has to do who turns the skins into leather is to preserve them from rotting, to keep them soft and flexible, and to make them look as nice as he can. This work is called tanning, and the place where it is done is called a tan-yard.

The skins are first soaked in pits filled with lime-water—that is, water with which some quick-lime has been mixed. This loosens both the hair and the fat. The skins are then taken out and scraped on both sides with long two-handled knives.

After this has been done, the skins are so soft that they look almost like sheets of jelly. These jelly-like skins are well rinsed in fresh water, and are then put to soak in large pits filled with water and the bark of the oak-tree. The water draws out of this bark a substance known as tannin; and the tannin changes the soft, jelly-like skins into tough, strong leather. This takes a long time, and the skins have to remain in the tan-pits for about a year.