32 BULLETIN 194, U. S. DEPARTMENT OF AGRICULTURE. 
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 depth 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 n=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-ll, 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 20^° 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 surfaced. 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 constructed 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 unsurfaced 
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- 
