410 



ting edge. It was impossible to slit hard timber smooth with it 

 until I cut the teeth all away and made new ones in it about half 

 an inch apart. Now it saws as true and smooth, with the same 

 power and velocity, as it is possible for a saw to cut. I used for 

 several years a 2 2 -inch circular wood-saw, whose teeth were three 

 inches apart at the points, and it always worked very unsatisfac 

 torily. Another one was put in its place, having teeth an inch 

 and a fourth apart, and with the same power it would saw nearly 

 twice as fast, and do it very smoothly. 



PUTTING SAWS IN ORDER 



611. Is an operation that requires the exercise of much dex 

 terity and mechanical precision. If the teeth are all filed to a 

 sharp point, unless they are perfectly even and true on the points, 

 a saw will not cut as fast as it ought, nor as fast as it would, if it 

 were well filed. When a saw is well filed and the teeth set 

 properly, by casting the eye over the teeth, lengthways of the 

 saw, not the least variation in the length of the teeth can be 

 discovered. Where some of the teeth are longer than the rest, 

 the long ones only will cut ; and so far as cutting is concerned, 

 the short ones might as well not be there. When a few teeth 

 only have been dulled, the saw will cut no faster by filing these 

 dulled ones to a point, unless the rest of the teeth are jointed off 

 and made of a corresponding length. In such instances it would 

 be as well to let them remain as they are until the remainder of 

 the teeth need filing. In filing, the aim should be to keep the 

 teeth of a uniform shape, i. e., the angle of what is called the 

 hook of the teeth, should be retained as much as possible. Many 

 farmers, not understanding the importance of this, continue to 

 file with a file that is nearly worn out on its corners, and thus 

 the hook of the teeth becomes not only very obtuse, but the teeth 

 are not kept as long as they should be. It is poor policy to file 

 a saw with a file the corners of which are worn out. It is very 

 important that the corners of file should be sharp, in order to 

 keep all the teeth as long as possible. If a tooth has been short 

 ened on the point by dulling or filing, it should be filed to its 



