THE YOUNG FARMER'S MANUAL. 



433 



be in perfect order. A few practical directions may not be amiss 

 on the sjjfect of 



TEETH IN SAWS WHICH WORK UP AND DOWN. 



66. Fig. 186 represents a mill saw having five different forms 

 of teeth. At a the teeth are filed on the FIG. 186. 



face, at a right angle with the cutting 

 edge of the saw, and the backs, or upper 

 sides, at an angle of forty-five degrees. 

 This is the oldest and most common form 

 of teeth, and whether filed square or 

 bevelling, more power is required to drive 

 a saw having this kind of teeth, unless 

 they are hammered as at e. Teeth of 

 this form remove the sawdust by scraping 

 instead of cutting. It requires less skill to 

 keep such teeth in good order than either 

 of the other kinds. 



667. At 5 much the same kind of teeth 

 is shown, with the faces filed at an acute 

 angle, giving them a greater hook, while 

 the lacks are of the same angle. If the 

 motion were high, such teeth will cut 

 much faster, with the same power, than 

 the kind at a. But if the motion be very 

 slow, teeth with much hook are liable to 

 draw into the log farther than they are 

 able to cut without staggering or trembling, 

 as if having too much feed. 



668. At c and d are two different kinds 

 of teeth, which operate with far less 

 power than those at a and 5, but they 

 require much more skill to keep them in 

 order. But by using a templet (see Fig. 

 185), any one who is able to put the teeth 



of any saw in order will find little difficulty v.-illi those. The 



