THE IMPLEMENTS OF THE FARM. 15 



resemblance to each other in the general principle of con- 

 struction. The best have iron frames (so as to preserve 

 the bearings in truthful working positions) on two road 

 wheels, with the ringer bar in a line with the main axle, 

 and the crankshaft is as low as practicable, purposely that 

 the thrust and pull may be equal. The cutter bar should 

 be adjustable for regulating the length of the stubble ; and 

 it should fold up. Spur gear is preferable to bevel gear, 

 especially for quick speeds ; and the teeth should be ex- 

 ternal or open, to prevent clogging. There should be two 

 speeds to suit different crops, and clutch gear should be 

 used for throwing into and out of gear. All these adjust- 

 ments should be under the control of the driver in his seat, 

 and without stopping his team. The bearings should be 

 self-lubricating, and protected from dust. But instead of 

 the cutter-bar being in a line with the wheels, it is yet 

 more frequently either in front or in the rear. 



The knife is composed of what are technically termed 

 sections riveted to the cutter bar. The sections are of 

 various forms, and are either of an acute or obtuse angle, 

 the two sides of the angle having a smooth cutting edge 

 like a chisel. The edges of the fingers against which the 

 sections make a shear cut are made of steel, and the fingers 

 are made of wrought iron, malleable cast iron, or wrought 

 iron and steel. 



A combined mower and reaper with manual side or back 

 delivery, is simply a mower, with a platform, grain wheel, 

 and divider, the track-clearer being removed. With side 

 delivery, a quadrant platform is required ; for back delivery, 

 a sparred tipping platform is used, the stubble, when the 

 drop takes place, assisting to discharge the gavel. Auto- 

 matic back delivery machines are also made. 



