64 BULLETIN 194, U. S. DEPARTMENT OF AGRICULTURE. 
WOODEN FLUMES. 
Nos. 60, 61, 62, 63, VMC+, Orchard Mesa Power Canal near Palisade, Colo. Lumber, 
planed, with tongued and grooved joints and with vertical pieces of 2 by 4 inch lumber 
in nearly all sections to check velocity in low discharge to keep flume wet. Straight 
reaches from less than 100 up to 600 feet long, joined at angular turns. Flume built 
in 1909-10. Has sagged below grade 0.3 foot in places. Of 22 reaches tested 17 show 
higher values of n for highest than for lowest discharge. The average value of n was 
0.0122 for 75 tests on 22 reaches. 
No. 69, Pv. S., Fargo drop, Boise project, United States Reclamation Service. 
Smooth planed plank coated with tar. Coefficient n=0.0122. 
Xo. 76, SF-23**, Bear River Canal flume over Malad River, Utah. Test made on 
125-foot wooden portion of flume. Reach above was 200 feet of iron and steel flume 
lined with riveted plates. Lower portion of planed wood. No gravel or sediment. 
Coefficient n=0.0142. 
No. 81, VMC+, Oxford Canal, Fowler, Colo. Structure 23 years old. In good 
condition as to grade and alignment. Sides of 2 by 12 inch lumber battened with 
\ by 3 inch strips. Floor laid at right angles to axis of flume. Though apparently 
smooth, has a high frictional factor. Tendency to cause deposit of silt lessens leakage. 
Coeflicient n=0.0150. 
No. 92, SF-45**, small flume near Corinne, Utah. Planed lumber calked with 
oakum which projected in places. Coefficient n=0.0184. 
No. 95, SF-8**, Bear River Canal, Utah. At mouth of Bear River Canyon. Origi- 
nally of planed lumber, the floor was almost entirely covered with sediment and rock 
fragments. Coefficient n=0.0201. 
No. 97, SF-10**, Bear River Canal, Utah. Located 2 miles above No. 95. Floor 
covered with sediment, gravel, and small cobbles. Coefficient n=0.0217. 
METAL FLUMES WITH SMOOTH INTERIOR. 
No. 98, VMC+, Minnesota Canal near Paonia, Colo. Grade not uniform. No 
transverse bracing, so flume sagged and took parabolic rather than semicircular form. 
This reach 200 feet long. On similar reach 70 feet long found n to be 0.0111, but this 
reach is too short for good test. Coefficient n=0.0099. 
No. 99, VMC+, Garland Canal, Trinchera Irrigation District, Colorado. A new 
No. 168 flume in perfect alignment and excellently constructed. Coefficient 
n=0.0101. 
No. 100, R. S., Boise project, United States Reclamation Service. This flume has 
a lap joint with smooth interior. It is 30 inches in diameter; was new and clean. 
Coefficient n=0.0106. 
No. 101, R. S., Boise project, United States Reclamation Service. This flume has 
outside and inside stay rods. Interior smooth and clean. Semicircumference 80 
inches long. Coefficient n=0.0117. 
No. 102, R. S., Mora Canal, Idaho. Smooth, clean interior. Semicircumference 
108 inches long. Coefficient n=0.0112. 
No. 103, R. S., Yarnell lateral, Idaho. Smooth, clean interior. Semicircumference 
72 inches long. Coefficient n=0.0122. 
No. 104, VMC+. Another reach on flume No. 99 above. Same conditions. 
Coefficient n=0.0126. 
METAL FLUMES WITH PROJECTING INTERIOR BANDS. 
No. 105, R. S., Partridge lateral, Idaho. Semicircumference 48 inches long. 
Flume clean. Coefficient n=0.0127. 
No. 106, R. S., Golden Gulch flume, Idaho. Semicircumference 108 inches long. 
Flume clean. Coefficient n=0.0129. 
