1084 



Farm Drainage Machinery. 



[FEB., 



that the operator can sight across it to targets set along the 

 line of trench at a known height above the desired bottom, 

 and the machines thus cut true to a given gradient. 

 Manufacturers now fit these machines, especially the heavier 

 ones, with multipedal or caterpillar tracks, although some of 

 the lighter machines are still mounted on four wheels. The 

 machines are moved by applying the power directly to turn 

 the wheels or tracks. The speed at which the machine moves 

 forward can be regulated by the traction gears, which may be 

 changed at will. Shields are fitted to the machine to prevent 

 the sides of the trenches from caving in when ditching in very 

 soft soil. The shields are usually about 8 ft. long, or sufiicient 

 to permit the tiles being laid properly. The machines vary 

 in size and weight — from a machine capable of digging trenches 

 10 in. wide by 4 J ft. deep and weighing 7 tons, to machines 

 that will dig trenches 36 in. wide by 7 J ft. deep, and weighing 

 about 22 tons. 



(a) Wheel Excavator. — Fig. 8 illustrates a machine used 

 extensively by contractors for tile drainage on the farms of 

 Ontario and Eastern Canada. The machine weighs about 



7 tons ; its length over all is 25 ft., and its width over all is 



8 ft. 6 in. The power is supplied by an internal combustion 

 14-h.p. single-cyHnder engine. The digging is done by buckets 

 on the rim of a wheel which is revolved in the trench : as each 

 bucket reaches the top of the circle, the soil falls upon a conveyer 

 belt : the belt can be adjusted to deposit on either side of the 

 trench. Cleaning devices are furnished to remove sticky earth 

 from the buckets. Digging wheels are supplied to take buckets 

 in sizes from it J to 14 in. wide and to dig 4 J to 5 J ft. deep. 

 Two men are required to operate the machine and to lay and 

 Hind* the tile. The fuel required for ordinary tile drains 

 averaging 3 ft. deep and 12 in. wide is 5 to 8 gal. of petrol 

 per 10 -hour day. Upon this class of work the machine will do 

 80 to 200 rods a day, depending principally upon the nature 

 of the soil. The cost of this machine is about £750. 



(b) Endless Chain Excavator. — Fig. 9 shows a machine of the 

 endless chain elevator class. Machines of this kind are built 

 in a greater range of sizes, so far as chain and buckets are con- 

 cerned, than wheel excavators of the same weight. They 

 also seem to be better adapted for work where there is need of 

 14 in. and larger tiles, and generally where there is a heavier 

 task to perform. The digging apparatus (Fig. 10) is operated 



* i.e. to fill in sufficient earth to hold the tile in place. 



