66 



FARM MECHANICS 



camber, or belly, to correspond with the sway-back. 

 The camber facilitates cutting to the bottom in mitre- 

 box work without sawing into the bed piece of the box. 

 It also throws the greatest weight of the thrust upon 

 the middle teeth. A saw with even teeth cuts smoother, 

 runs truer and works faster than a saw filed by guess. 

 It is easy to file a saw when all of the teeth are the same 



Old File 

 : R ivet to Prevent 

 5plittincj of Block 



6.G.B. 



Figure 95. Saw Jointer. The wooden block is about two inches 

 square by 12" or 14" in length. The block is made true and scribed 

 carefully to have the ripsaw slot square, straight and true. The 

 file is set into a mortise square with the block. 



length and all have the same set. Anyone can do a 

 good job of filing if the saw is made right to begin with, 

 but no one can put a saw in good working order with 

 a three-cornered file as his only tool. 



Filing the Handsaw. First comes the three-cor- 

 nered file. It should be just large enough to do the 

 work. There is no economy in buying larger files 

 thinking that each of the three corners will answer the 

 same purpose as a whole file of smaller size. In the 

 first place the small file is better controlled and will 

 do better work. In the second place the three corners 

 are needed to gum the bottoms of the divisions between 



