32 BULLETIN 194, U. S. DEPARTMENT OF AGEICULTUEE. 



countered. This lining, was a cement and sand coat about 1 inch thick, applied 

 directly to the trimmed surface of the earth channel. Occasional fractures in such 

 a lining are to be expected. Coefficient n=0.0221. 



No. 55, Expt. S-71, Riverside Water Co.'s Upper Canal, in Riverside, Cal. While 

 originally a canal lined with a well-built and but lightly pitted cement-wash surface 

 the bottom of the channel has completely lost its identity as a concrete lining in so 

 far as friction is concerned, since there is now more than 18 inches of sand in the 

 bottom. This drifts down the canal in little pockets that look Like hoof prints of 

 stock. The positions of these shift rapidly, causing the dei^th of water at a given 

 point to change 0.4 or 0.5 foot in about 30 minutes. This condition renders a measure- 

 ment by current meter using multiple points obviously inaccurate, and the writer 

 used the integration method, as the latter will give results as close to those found by 

 multiple points as can be desired. A measurement by this method takes but a few 

 minutes, and the canal bottom in this period probably does not shift sufficiently to 

 vitiate the results. As shown in Plate V, figure 3, there are no curves or structures 

 above the reach tested to change results, and the same condition holds downstream. 

 Coefficient n=0.0231. 



WOODEN FLUMES. 



No. 57, Expt. S-50, Reno Ditch, Reno Light & Power Co., Nevada. This flume 

 is built of 2 by 12-inch surface pine with all cracks battened with 1 by 4-inch strips. 

 This gives a retarding vertical batten about every 12 feet. As shown in Plate VI, 

 figure 1, the flume leads from the cobble-Lined ditch. No. 254, to the penstock above 

 the power house. The reach chosen begins about 100 feet below the upper end of 

 flume and extends for 800 feet down a tangent and around part of a gentle curve to a 

 point about 800 feet above the penstock. Coefficient ?i=0.0103. 



No. 58, Expt. H-30, Bitter Root Valley Irrigation Co.'s Canal, Montana. This 

 straight flume is built of 2^-inch tongued and grooved finished siding, with butt 

 joints calked with oakum. The interior was therefore free from battens or other 

 retarding construction. Station was about 100 feet below the flume intake from an 

 earth canal. Station 5 is about 50 feet above a trash, rack which was clean at the time 

 of measurement and does not appear to effect the flow. Coefficient n=0.0112. 



No. 59, Expt. B-11, King Hill flume, Idaho. This test was conducted August 7, 

 1911, in a flume Lined with a very smooth roofing material, which was placed in the 

 spring of that year. Longitudinal wooden strips worn very smooth by the water, 

 held the roofing in place. Coefficient n=0.0115. 



No. 64, Expt. S-34, Big flume. Central Oregon Irrigation Co. near Bend, Oreg. 

 As shown in Plate VI, figure 2, this flume is very sinuous, the reach of 1,100 feet 

 tested having an alignment as follows: Station 0-60 being at the P. T. of a 12° curve 

 right; thence on tangent 329.9 feet; thence around a 20° curve right, 135 feet; thence 

 reversing into a 20J° curve left for 256.1 feet; thence reversing again (at a point near 

 the ladder, in the figure) into a 17^° curve 211.7 feet; thence on a tangent for the 

 balance of the reach, 107.3 feet. The flume was originally constructed of surfaced 

 and sized 2 by 12-inch pine, with cracks battened with ^ by 3-inch strips surfaced 

 on one side and both edges. A washout necessitated rebuilding the flume in part, 

 and a few of the planks and battens in the rebuilt portion were not sm-faced. It is a 

 difficult matter to tell one from the other after a few months' use, as a slight deposit 

 of green slime makes the boards very smooth indeed. Bifurcation works divide the 

 water about 200 feet below station 11. The consti'ucted grade was 10.56 feet per 

 mile, or 0.002 feet per foot. Coefficient n=0.0117. 



Nos. 65, 66, 67, 68, H-16, Alkali Creek flume, Billings Land & Irrigation Co., Mon- 

 tana. Four tests were made in a straight reach of this flume, which, is of unsui-faced 

 lumber, somewhat waterworn and with slight deposits of slime and moss. The grade 

 of the bottom is excessive and irregular, causing extensive wave action when oper- 



