170 FARM MECHANICS 



made with a square base of timbers which supports an 

 upright mast and a horizontal boom. The timber base 

 is sixteen feet square, made of five sticks of timber, 

 each piece being 8x8 inches square by 16 feet in length. 

 Two of the timbers rest flat on the ground and are 

 rounded up at the ends to facilitate moving the derrick 

 across the stubble ground or along the road to the next 



Figure 150. Six-Tined Grapple Hayfork. It is balanced to hang 

 as shown in the drawing when empty. It sinks into the hay easily 

 and dumps quickly when the clutch is released. 



hayfield. These sleigh runner timbers are notched on 

 the upper side near each end and at the middle to re- 

 ceive the three cross timbers. The cross timbers also 

 are notched or recessed about a half inch deep to make 

 a sort of double mortise. The timbers are bound to- 

 gether at the intersections by iron U-clamps that pass 

 around both timbers and fasten through a flat iron 

 plate on top of the upper timbers. These flat plates or 

 bars have holes near the ends and the threaded ends of 

 the U-irons pass through these holes and the nuts are 



