SAWS.
saw, which is an ancient, useful, and familiar tool, has a history of its own. When we speak of a saw, we generally mean a tool for dividing wood, although the saw is used for other solid materials, and, moreover, has other uses than mere dividing. Thousands of years ago the Egyptians were acquainted with and used this tool, which was made of their celebrated bronze hardened by an art that for ages has been lost, as also have been many other arts employed in the daily work of those who dwelt in the land of Egypt. The supposed originator of the saw, Talus or Perdrix, was deified by reason of his invention, which was great because of its prime importance in building and ornamenting homes and articles of furniture, as well as vessels and vehicles, by which the brotherhood of man could be more firmly established and his wealth and power increased. But probably the introduction of this useful imple ment was not confined to any one inventor or originator. The idea doubt less suggested itself to hundreds of ingenious savages in many widely separftted portions of the globe, where the material employed, the style, and the method of its use, were equally diverse. The most primitive saw was probably made of a jagged piece of stone or shell; later on there was employed a wooden handle with a cutting edge of sharp teeth or of sim ilar cutting or rasping points, which worked their way through woods of various degrees of hardness at a rate depending upon the material and upon the strength and patience of the workman. In the Stone Age saws were made of wood with flint teeth. The Mexicans six centuries ago used long pieces of obsidian (a black stone sometimes called " natural glass"), the edges of which they had notched.
From the primitive and ineffective saw of stone, shell, or fish-teeth, through the period of the bronze plate with filed teeth, to the modern iron or steel saw, is a long step. A collection showing the successive and different manners of holding and working the blade would be exceedingly interesting. Each decade within the recollection of men not yet old has brought fresh advances in the manufacture and fresh triumphs in the use of this important industrial implement.
The (p. 10, 5) was so called because its use required one of the operators to stand in and the other over a pit, across which the log or tree was laid. The blade was tapering, and cross-handles were
attached for working the saw. The lower man or pit-man (from which originates the name given to the rod which connects a reciprocating with a rotating object, as that which couples a crank with a saw-gate) stands behind the blade to avoid the dust of the saw, which cuts on the down ward strokes. The pit-saw was crude and defective, its principal fauit being a degree of slowness which in its time was scarcely noticed, because there was then nothing, and little thought given to anything, more rapid.
Hand-powcr Saw-mill.—A more ambitious device is the board-mill shown in Figure i. There arc two hand-wheels (A, C), to which rods (DM) are attached for working the frame E, which is pivoted in the main frame and works the saw-frame up and down. On the upper end of this framework there are provided braces (FG), to which the saws are secured according to the number and thicknesses of boards required. The timber A. is placed on rollers, and each time the wheel at II is struck by the projection B on the wheel A, the log is moved forward; a strong rope or chain fastened under and at the end of the block K fastens itself over the axle of the wheel, and whenever the projection B of the wheel A grasps the former wheel at H, the timber is drawn forward for sawing.
Power mill shown in Figure 2 (bl. To) may be operated by one or two persons by means of a tread-wheel (A), to the beam of which there is attached a "trillis" (C) with strong spindles, and by this is turned the cog-wheels D and F, D moving on the spindle E, and F on the spindle C, the spindle E being attached to the centre of the cog wheel F. To the spindle E is attached the beam Q, which, by means of the crank P, moves the perpendicular bar that connects the saw L and its horizontal beam (Ai) upward and downward. The horiz'ontal beam ill is set in the grooves N, A; and the timber to be sawed is fastened with clamps in the rolling framework A, at the end of which there is attached a strong rope drawn over the roller 0 and wound on the wheel I, which is held in place (or held back) by the inclined bar or arm H.