120 ENGINEERING FOR LAND DRAINAGE. 



completely graded ditch at the rate of from lo to 20 

 rods per hour. It is governed and operated in the 

 same manner as a traction engine, is compactly built 

 and easily managed by two men. It cannot be ex- 

 pected that a machine of this character will work suc- 

 cessfully in ground so soft that it will not bear the 

 weight of the machine, nor in land full of stumps, 

 stones, and large roots. 



With these exceptions, there seem to be no diffi- 

 culties which are not successfully met by this machine. 



Contracts for Construction of Tile Drahis, 



The construction of drains for improving entire farms 

 and large areas of level land is frequently done by con- 

 tract subject to competent superintendence. The sys- 

 tem is laid out by an engineer and complete plans made 

 for the work, after which bids for the construction of 

 the drains are sohcited. The furnishing of the tile and 

 distribution as needed upon the ground is usually not 

 included in the ditching contract, neither is the filling 

 of the trenches. 



Tile are purchased by the thousand feet; hauling 

 from the railroad station or factory is done by the ton, 

 the weight of the individual pieces of different sizes 

 being used as a basis for determining the weight of the 

 loads; the digging of ditches and laying of tile is com- 

 monly done by the rod, but by the 100 feet would be 

 better, and filling of the ditches by the 100 feet. 



The following general specifications and contract 

 have been found useful in practice, and will serve as a 

 guide in preparing specifications for other work. It 



