PART IV.

Filing and Setting Hand-Saws.—The Qualities Required to make a Good Filer.—Rules in some Old-time Joiner Shops.—Careless Filing and its Consequences.—Clamping Saws for Filing.—The Line of Teeth.—Angular Groove on Cutting Edge of Saw.—Filing Backs of Teeth.—Jointing the Sides of Teeth.—Shape of Teeth for Cross-cutting Hard Wood, Medium and Soft Wood.—Cutting Angles Required for Various Degrees of Hardness in Woods.—Angle to Hold the File—The True Theory of Saw-Filing.—Buckling and Twisting Saws; How Done and How Avoided.—“Hook and Pitch.”—Careless Use of Saws, and the Injuries Done to them in Consequence.—The Filing of Different Saws, and why One Class of Saws Require Different Treatment from Another. The Saw that Scrapes, and the Saw that Cuts; the “Why” of this Difference.—Why Some Men do Much More Work than Others, and with Greater Ease, when Sawing.