Saw

a well known mechanic's tool. The modern saw consists of a steel blade provided with V-shaped or W-shaped teeth. The carpenter's saw is used in joinery, the buck-saw for cutting fuel, the cross-cut for timbers, the surgeon's saw for amputating limbs, etc. "Sawbones" is a popular nick-name for a surgeon. The term buzz-saw was applied first to a small circular saw used by watchmakers and others to cut metal. Quarrymen use saws in cutting blocks of marble and limestone. The builders of the Egyptian pyramids sawed out granite blocks with bronze saws set with jeweled teeth. The earliest prehistoric saws known have wooden blades in which flakes of flint are set for teeth by means of bitumen.

The saws used in sawmills are of three forms, the drag saw, which is pushed to and fro; the circular saw, the whirling edge of which strikes the wood; and the band saw. The latter is a vertical ribbon of metal running over pulleys like a belt. It is made of finely tempered steel and may be made so thin that far less of the log is wasted in sawdust than when cut with a saw of an other pattern. The gang saw consists of a number of blades operated in a single frame, so as to cut an entire log into boards at one operation. The circular saw dates from 1790. The band saw was invented a half century later. For all saws, it is necessary to set the teeth, that is, to bend half the teeth slightly to one side and half to the other in order to make a cut slightly wider than the blade is thick. The greener the timber, the more set the saw requires. The surgeon's saw is without set and the blade tapers gradually--grows thinner--toward the back. In 1900 there were ninety-six saw-making factories in the United States, turning out an annual production valued at $6,443,708.

It is interesting to know that the name, "Sierra," applied to numerous mountain chains, is a Spanish word meaning "saw," having reference to the notched or tooth-like appearance of the mountain chains.