l68 FARM MACHINERY 



their replacement when worn. If slightly worn, they may 

 be hammered down until the proper amount of play be- 

 tween the clip and the sickle is obtained. Under normal 

 conditions, this is about i/ioo of an inch. In no case 

 should it be so open as to permit grass to wedge under 

 the clips, but at all times should hold the knife well upon 

 the ledger plates so as to give the proper shearing action. 



237. Mower guards are fitted with two kinds of ledger 

 plates, one with a smooth edge and the other with a 

 serrated edge. The serrated plate holds fine grasses to 

 better advantage than the smooth ledger plate, and in this 

 way aids with the cutting. 



238. Shoes. The cutter bar should be provided with 

 an adjustable shoe at each end, by means of which the 

 height of cut may be varied to some extent. A weed at- 

 tachment is often provided which will enable the cutter 

 bar to be raised 10 inches or more. A shoe is better than 

 a small wheel at the outer end of the bar because the 

 wheel will drop into small holes, while the runner will 

 bridge them. 



239. The grass board. The purpose of the grass board 

 and the grass stick is to rake the grass away from the 

 edge of the swath to give a clean place for the inside shoe 

 the next round. The grass board should be provided with 

 a spring to make it more flexible and less apt to be broken 

 in backing and turning. 



240. Foot lifts. Nearly all modern mowers are now 

 provided with a foot lift, which enables the operator to 

 lift the cutter bar over obstructions, and also makes 

 easier work for the team by lifting the bar while turning. 

 A spring is necessary to aid in the lifting. 



Certain mowers, known as vertical lift mowers, permit 

 the cutter bar to be lifted to a vertical position by a lever, 

 to pass obstructions, and at the same time the mower is 



