It is so wide in bite, however, that it wastes much wood in sawdust.

For example, in cutting four boards of one-inch lumber, an ordinary circular saw wastes enough material to make a fifth board, because it cuts an opening that is one-quarter of an inch in width.

Band saws, although they do not work at such high speed, are replacing circular saws in many mills because they are less wasteful of lumber.

Although sawmills try to prevent waste of wood by converting slabs and short pieces into laths and shingles, large amounts of refuse, such as sawdust, slabs and edgings, are burned each season.

As a rule, only about one-third of the tree is finally used for construction purposes, the balance being wasted in one way or another..