THE IBKIGATION AGE. 



angle, leaves both banks and bottom perfectly smootii 

 and delivers waste banks at a distance from the ditch, 

 producing broad, clean berms which prevent the spoil 

 banks being returned to the ditch. 



A photograph of a ditch made by this method 

 in central Illinois, which was one year old at the time 

 the view was taken, fully demonstrates that if a ditch 

 be made in this manner, resistance to the flow of water 

 in all parts of the banks is equal, and as a consequence 

 there is no tendency of the banks to cave, the current 

 is not deflected from side to side and the ditch be- 

 comes a permanent waterway of its original maximum 

 capacity. 



Front view of Austin Drainage Excavator in operation, showing manner 

 in which machine rests on track on both sides of ditch. 



A view of a dipper dredge is shown operating ir> 

 central Illinois only two miles distant from where 

 the Austin drainage excavator illustrated was at work 

 and soil conditions in the two ditches were identical. 



View of a dipper dredge in operation, showing the vertical banks and 

 waste bank constructed immediately adjoining ditch. 



This style of dipper dredge requires water in which to 

 operate and as a result the exact form of the excav?- 

 tion cannot be determined until the ditch is completed. 



This machine can only construct practically vertical 

 banks and it will be seen in the photograph that the 

 waste bank is delivered in a position where a large por- 

 tion of it is certain to be returned to the ditch. This 

 condition is also shown in view of a new ditch con- 

 structed by a dipper dredge and illustrates why ditches 

 dug by this method require reconstruction within a few 

 years' time. In the view of a comparatively new ditch 

 made in northwestern Iowa by a dipper dredge it will 

 be noted that the banks have caved practically through- 

 out their entire length, portions of the banks have been 

 carried to the center of the ditch, obstructing nearly 

 the entire channel, and it is evident that this entire 

 ditch will require reconstruction in a short time. 



In the ditch building in Cass County, Indiana, by 

 the Austin drainage excavator and which is twelve feet 

 deep with a four-foot bottom and a one and one-half 

 to one slope, if carrying a variable quantity of water 

 and a minimum flow were equal to six inches of water 

 in the rectangular shaped ditch, with a ten-foot width 

 of bottom in Mr. Elliott's table given above, it is ob- 

 vious that the water in this ditch would have more 

 than double the depth and consequently more than 

 twice the velocity as the same amount of water in the 

 rectangular shaped ditch and this ditch will therefore 

 be self-cleaning under conditions which would make 

 the rectangular ditch fill rapidly with silt. 



An illustration of a three-year-old ditch built by dipper dredge in 

 northwestern Iowa, showing banks caved practically through- 

 out their entire length and demonstrating why ditches 

 built in this manner require frequent reconstruction. 



We are illustrating a perspective of the Austin 

 drainage excavator constructing a ditch eight feet deep 

 with a six-foot width of bottom and showing the slope 

 of banks, width of top and width of berm when the 

 ditch is made by this method with a one to one slope 

 and also with a one and one-half to one slope. It will 

 be noted that since the excavating bucket travels in 

 a steel guideway transversely of the ditch, and as the 

 entire guide frame is lowered as the ditch increases in 

 depth, a bucket in excavating shaves off a thin slice 

 down one side, across the bottom and up the opposite 

 side and travels out on the opposite arm to discharge its 

 load. By .this method of excavating the entire ma- 

 chine is under perfect control of the operator at all 

 times and it is possible to shave off a fraction of an 





