THE IRRIGATION AGE. 



the slopes and beds, and even if practicable, the cost 

 might not justify it. The lack of rolling must be made 

 up by using more oil, and in these experiments a greater 

 quantity of oil was used per square yard than is ordi- 

 narily used on roads. Mixtures of oil and gravel were 

 also used in the experiments, and while they were costly, 

 they were at the same time unsatisfactory, proving very 

 poor linings for stopping seepage, as will be shown later. 

 The order in which the ditches were planned at first 

 is as follows, the ditches being numbered from east to 

 west : 



No. 1. Lined with a mixture of heavy road oil and 

 gravel in the proportion of one part of oil to eight parts 

 of gravel. The lining was 3y 2 inches thick. 



No. 2. Earth (no lining). 



No. 3. Lined with a mixture of heavy road oil 

 and gravel in the proportion of one part of oil to six 

 parts of gravel. The lining was 2y 2 inches thick. 



No. 4. Heavy road oil sprinkled, using 3% gal- 

 lons per square yard. 



No. 5. Earth (no lining). 



No. 6. Thin oil sprinkled, using %y 2 gallons per 

 square yard. 



No". 7. Clay puddle, 3% inches thick. 



No. 8. Earth (no lining). 



No. 9. Cement mortar, 1 inch thick. 



No. 10. Cement concrete, 2y 2 inches thick. 



No. 11. Earth (no lining). 



No. 12. Cement lime concrete, 2 J /2 inches thick. 



It will be noticed that arranging the ditches as 

 above, there are eight ditches lined and four earth 

 ditches with no lining. Each earth ditch has an ad- 

 jacent lined ditch on each side, so that in case the seep- 

 age from the four earth ditches was unequal, the seepage 

 in the lined ditches could be compared with the seep- 

 age from the adjacent (or nearest) earth ditch. The 

 lined ditches would also be affected more nearly equally 

 by the seepage from the earth ditch. 



METHOD OF FINISHING DITCHES. 



After the excavation with teams the ditches were 

 finished by hand in the following manner (Fig. 14) : 

 Pieces of timber, 2 inches by 3 inches, were placed at 

 the center of the banks between ditches, and extending 

 parallel to them from one end of the ditch to the other ; 

 these pieces of timber were placed in the banks and 

 made level. The tops of these timbers were at the same 

 level as the banks. Frames or templets were built, as 

 illustrated, of the same size as the finished ditch, ready 

 for the lining. Four of these frames were used, the 

 same one being used for the four earth ditches and for 

 ditches where the oil was sprinkled on the slopes and 

 bottom. A second form was used for the cement motar 

 lined ditch; this form was larger than the previous 

 one, allowing 1 inch for the lining. The third form 

 was made large enough so that the ditch finished with 

 this form, after being lined with a 21/o-inch lining, 

 would be of the same cross-section as the earth ditch. 

 The fourth form was used where the ditch was to be 

 lined with a S-i/rjinch lining. 



These frames were used in the following manner 

 (Fig. 15) : Beginning at one end of the frame was 

 placed in the ditch and the side slopes and bed were 

 cut down until the top piece of the frame would rest 

 on the two pieces of timber on the banks. The frame 



then moved forward on these guides and the cross- 



section was cut down with spades to the proper size. 

 The slopes were finished first and the earth cut from 

 the slopes was removed with a scoop scraper. The 

 cost of finishing was about 1 cent per square foot. 



METHOD OF LINING. 



No. 1. The oil was heated to a temperature of 

 about 180 Fahr., at which temperature it would 

 flow easily. This heated oil was mixed with the gravel 

 in the proportion of one part of oil to eight parts of 

 gravel by volume. The mixing was done with rakes 

 and the mixture was very uniform. The sides were 

 lined first. 



Pieces of timber 3y 2 inches thick were placed on 

 the slopes at right angles to the axis of the ditch, about 

 every 10 feet. The oil-gravel mixture was carried in 

 wheelbarrows and dumped on the slopes between these 

 timbers. A straight edge about 12 feet long, extending 

 from one timber to the other and worked up and down 

 the slope, regulated the thickness of the lining to 3y% 

 inches. The mixture was tamped while being placed 

 in position. 



No. 3. This ditch was lined in exactly the same 

 manner. The mixture used contained one part of 

 heavy Bakersfield oil to six parts of gravel. The thick- 

 ness of the' lining was only 2y 2 inches; the slope timbers 

 being therefore 2i/ 2 inches thick instead of Sy 2 inches 

 thick, as for No. 1. 



No. 4. This ditch was lined with the same heavy 

 oil. The oil was heated to a temperature of 180 

 Fahr., and was sprinkled or poured on the slopes with 

 a 3-gallon watering pot, with the rose sprinkler flattened 

 so as to throw a flat stream or sheet of oil on the side 

 of the ditch. The oil was applied mostly on the top 

 of the slope, and as it ran down the slope it was grad- 

 ually absorbed by the ground some of it reaching the 

 bottom. An excess of oil accumulating at the bottom 

 was dragged up the slopes by using a stick about 8 feet 

 in length to which a 2-foot piece of timber was nailed, 

 at right angles, at one end, and to this piece was 

 nailed a couple of sacks to be used as a mop. If the 

 oil is not applied in large quantities at once, but in- 

 stead several successive light applications are made, it 

 will not be found necessary to use this mop. 



The oil was not raked in; the object sought for 

 was to have the oil form a thoroughly saturated crust; 

 while if it was raked or plowed in, the oil may have been 

 disseminated through too thick a layer to form a water 

 tight crust. 



No. 6. The sixth ditch was sprinkled with lighter 

 oil in exactly the same manner as the fourth ditch, 

 using 21/0 gallons per square yard. 



No. 7. The seventh ditch was lined with clay 

 puddle. The clay was difficult to obtain, having to be 

 hauled about three miles, which made it very costly. 

 The clay contained fine silt and sand. It was sprinkled 

 with water, and when soft was hauled in wheelbarrows 

 and applied in the same manner as the oil-gravel mix- 

 ture. The thickness of the lining was 3y 2 inches. 



No. 9. The ninth ditch was lined with cement 

 mortar, composed of one part of cement to five parts of 

 gravel. The lining being 1 inch thick, the scantlings 

 or guides placed on the slopes were only 1 inch thick. 



No. 10. This ditch was lined with cement con- 

 crete 21/0 inches thick, composed of one part of cement 

 to seven parts of gravel and crushed rock, in equal 

 quantities. 



