378 THE YOUNG FARMER'S MANUAL. 



FlG. 149. 



A GRINDSTONE WITH CLAMP FOR HOLDING TOOLS WHILE GRINDING THEM. 



made near the bottom of it with an awl, so that the water will 

 drop just fast enough to keep the stone wet. 



542. Grindstones should always be protected from the influences 

 of the weather, and especially from the rays of the summer's sun. 

 Sometimes the sun will affect them so as to render them very 

 hard ; and sometimes the rain, frost and sunshine will check them, 

 or cause them to crumble. In order to grind edge tools correctly, 

 the workman should understand very well the difference be 

 tween a 



CRUSHING STROKE, AND A DRAWING OR SLIDING STROKE. 



543. Edge tools of every description operate most effectively 

 by being drawn diagonally as they enter the materials to be cut ; 

 and any substance can be cut with far less force when the cutting 

 instrument is made to operate in a diagonal direction than if it 

 were forced square through it. When a cutting instrument is 

 forced straight into or through any substance, it is said to have a 

 crushing stroke ; and when the cutting edge is made to enter, and 



