381 



the long hoofs of sheep. Common shears make a crushing cut ; 

 but when this kind of shears is opened, the connecting rod, in 

 closing them, slides one blade along, so that the centre is at the 

 other end of the slot. They can be obtained at Allen's Agricul 

 tural Warehouse, 89 Water street, N. Y. city. 



GRINDING EDGE TOOLS. 



" The flashing knives upou the grinding disk 

 Are held, with grating and discordant sound." T. B. READ. 



548. The young farmer doubtless understands that the process 

 of grinding and whetting tools is performed very similar to re 

 ducing the thickness of a board, by planing it with a gouge- 

 shaped plane. The grit of the stone enters the steel, and scratches 

 numerous little furrows in it, removing the metal as soon as it is 

 cut loose. If the grit is coarse, the scratches will be much deeper 

 and wider, and farther apart than if the grit is fine. If the 

 scratches extend to the cutting edge of the tool, the edge will be 

 full of serrature, coarse or fine, corresponding with the grit of the 

 stone. If the scratches are made at a right angle with the cut 

 ting edge, the serrature will stand at a right angle also. But if 

 the tool when grinding is held in such a position that the scratches 

 are made at different angles, the serrature will be hooked, or stand 

 at the same angle with the scratches on the sides of the tool. 

 Now, when a tool is designed for cutting wood or iron, or any 

 other kind of hard substances, it is best to grind it and whet it 

 while it is held in such a position, that the scratches and serra 

 ture will stand at a right angle with the cutting edge, whether 

 the tool makes a crushing cut or drawing cut. But when a tool 

 is designed for cutting soft, spongy substances, and is used with 

 a draw cut, it should be ground and whet so that the serrature 

 will stand at an acute angle, or be " hooked." 



549. Let a case-knife be ground so that the scratches will be 

 at an angle of forty -five degrees towards the handle, and let it be 

 whet by drawing it on a fine-gritted stone, from heel to point 

 across the stone, and attempt to cut a loaf of soft bread with it. 

 by drawing the knife towards you, and if the knife is a good one 



