THE YOUNG FAKMEK'S MANUAL. 

 FlG. 152. 



387 



SHOWING THE PROPER ANGLE FOR GRINDING COLD-OHISELS. 



564. The knives of mowers and reapers usually cut with a 

 crushing stroke. Therefore, the more acute the angle of the 

 basil the more easily they cut. But if they are ground too thin 

 they are more liable to be dulled by breaking out at the edge, 

 than if they were ground at a more obtuse angle. All things 

 considered, if such knives are ground at an angle of twenty de 

 grees, the basil will be acute enough for all kinds of work. 



OIL-STONES 



565. Are almost as indispensable as a grindstone. Indeed, it 

 is very impracticable to produce a fine, keen edge without one. 

 They may be obtained at the hardware stores for about fifteen 

 cents. Set it in a wooden block, and use sweet oil on it when 

 whetting a tool instead of water, because oil will aid in giving a 

 tool a keener edge. Nail a strap of old leather on one side of 

 the oil-stone case, and after a chisel or plane -iron has been whet, 



