184 



FELLING AND CONVERSION OF TIMBER. 



edge a c, and by leaving a larger space between the teeth than 

 their own area. In old-fashioned saws this was provided for by 

 breaking-off the tops of some of the teeth at regular intervals, 



Fig 94. American combined dog'and M teeth. 



as in Fig. 96, but such imperfect teeth are not found in modern 

 saws. The dog teeth between the combined M teeth of 

 American saws may be considered as planing- teeth for remov- 



Fig. 95. Saw with deep intervals 

 between the teeth. 



Fig. 9f>. Saw with imperfect teeth, 



ing splinters of wood, as they are not set like the other teeth. 

 They may also serve as cutting teeth and then are sharpened, 

 (c) Shape of Saws. Various kinds of saws have come into 

 use in different countries, of which the following are the most 

 serviceable : 



i. Two-handed Saws. 



The two-handed forest saws comprise the straight, bow, 

 and curved cross-cut saws. 



The straight cross-cut saw is 4J by 5 feet long, with a 



Kig. 97. American saw. 



breadth of blade of 4j to 5f inches. The handles are placed 

 at right angles to the cutting edge of the saw, which consists 

 of dog teeth with some shortened ones, and the bladi; is 



