278 



THE IRRIGATION AGE. 



the bottom and sides are more or less torn up by the 

 shovel. It is therefore necessary to grade such ditches 

 down to sloping banks, else they will be much more 

 irregularly formed by caving banks. It is well known 

 that water seeps through loose earth more rapidly than 

 the original strata of the earth, and in a ditch built with 

 properly sloped, perfectly true banks, leaving the orig- 

 inal strata of the earth in banks and bottom undis- 

 turbed, and with all loose earth removed, there will be 

 far less seepage than when constructed in an irregular 

 manner and graded down or left to nature to cave the 

 banks to the proper slope. 



Where there is a large amount of seepage near land 

 of a lower level the low lands not only frequently become 

 saturated with water, but if there is a considerable 

 amount of alkali this concentrates in these lands, mak- 



Chicago. This excavator operates on an entirely new 

 principle and is especially adapted for irrigation work, 

 not only on account of the superior manner in which 

 the ditch is made, but also for the reason that no water 

 is required in which to operate the machine. 



This machine constructs a ditch of practically any 

 depth, width of top or width of bottom desired, and 

 slopes the sides to any angle at a single operation. The 

 waste banks are also constructed at a distance from 

 the ditch and they may be made continuous to serve as 

 dykes, thus increasing the capacity of the ditch, or the 

 earth can be delivered to either side. 



In operation the machine rests on a track having 

 one rail on each side of the ditch and excavates with 

 equal rapidity traveling forward or backward. The 

 excavating buckets travel in guide-ways transversely of 



This Ditch Was Made by the Austin Drainage Excavator and Had Passed Through the Frosts and Freshets of One Winter at the Time 



This Photograph Was Taken. 



ing them absolutely worthless until a drainage system 

 is provided at a cost often nearly equal to the expense of 

 the irrigation system, and it then often requires sev- 

 eral years to remove the alkali from these lands suffi- 

 ciently to make them crop producing. Irrigation 

 ditches constructed on a scientifically correct principle, 

 therefore, not only husband the water in the irrigation 

 mains, but also obviate the construction of a drainage 

 system and almost entirely overcome the danger of the 

 accumulation of surplus alkali. 



A machine which has been on the market about 

 three years and which is attracting a great deal of at- 

 tention among engineers engaged in reclaiming arid 

 lands is the Austin drainage excavator, manufactured 

 by the F. C. Austin Drainage Excavator Company, of 



the ditch and shave off a thin slice down one side, across 

 the bottom and up the opposite side. 



The frame carrying the buckets is lowered as the 

 ditch increases in depth, so that the banks and bottom 

 are cut to exact specification. There is no loose earth 

 in the ditch and- the original strata of earth in the 

 banks and bottom are imdisturbed and remain as firm 

 as nature made them. 



A ditch built in this manner and left perfectly 

 smooth contains no obstructions and will therefore main- 

 tain a maximum flow of water, and since the ditch is 

 cut out of the solid strata of the earth, with banks 

 and bottom remaining firm and true to grade, a small 

 amount of silt will form a film over the surface, cement- 

 ing the sides and bottom, thus assuring a permanent 

 waterway of largest possible capacity. 



