80 



INSTALLATION OF TKENCHING 



Fig. 47. Fondeur's Plant. 



ground throughout its length. This operation is easy when 

 the ground is slightly damp, for the penetration takes place 

 of itself. If not, it is necessary to drive pegs P in a 

 slanting direction, or to increase the weight of the system by 

 cases C filled with earth. . Finally, to prevent the rollers 

 from becoming derailed, the cable must be kept as close as 

 possible to the ground. If not the machine has a tendency 

 to tilt over in the direction of the arrowy. 



With such an installation four girders only are necessary, 

 alternately displacing each pair. 



With the object of dispensing with the horse and boy 

 required for hauling the plough back, implement makers 

 construct capstans provided with an additional mechanism 

 which does the work. This device is undoubtedly handy 

 when steam is used, but complicates the horse-gin unneces- 

 sarily. The cable used is 0-35 to 0-39 inch in diameter. 



