81 



4. Grubbing axes. 



Grubbing axes . serve the double purpose of digging up the soil 

 round roots and severing those which do not exceed 3 or 4 inches 

 in diameter. The blade should always be slightly curved, and 

 about 12 inches long and from 2 to 4 broad at the edge. Fig. 25 

 represents three effective forms. 



Fig. 25. 



ZJ 



Grubbing axes (tV*'* natural size). 

 Ahtiole 3. — The Saw. 



The saw consists of a thin, comparatively broad blade or plate 

 of steel, one edge of which is toothed. The saw is essentially a tool 

 for use across the fibres of the wood. If the fibres of wood were 

 perfectly parallel and there were no discontinuity due to branches, 

 knots and other causes of transverse or irregular growth, then 

 all longitudinal separation would be efiected by tools acting solely 

 on the principle of the wedge. It is because of such discon- 

 tinuity that the saw is also used for cutting wood longitudinally, 

 ripping as it is technically called. 



The following are some of the technical terms used in connection 

 with saws: — 



Rake, the inclination of the line of the teeth, in a straight saw, 

 to the direction in which the saw moves. 



Space, the distance from tooth to tooth measured at the points. 



Face of a tooth, the profile of the tooth facing the side towards 

 which the saw moves in cutting. 



Back of a tooth, the opposite profile. 



