20 The Colorado Experiment Station 
sations being used in computing the slopes and other hydraulic 
elements. 
Table 7 gives the results of these experiments. To make any 
variation in the value of (n) apparent, the experiments are ar¬ 
ranged according to discharge from least to greatest. An average 
of 1-3, 2-4, 3-5 indicate mean values of (n) to be .0122, .0117 and 
.0121, respectively, from which a comparison can be made. These 
limited data do not throw any light upon the variation in the value 
of (11) with the discharge. The mean coefficient of roughness for 
this chute is .012. 
REINFORCED CONCRETE FLUME OVER DRY 
CREEK, HANDY CANAL, LOVELAND. This flume has a 
maximum elevation above the creek bed of about 30 feet, and is 
supported upon concrete columns. The total length is approxi¬ 
mately 650 feet, and it is built in two sections of different grades, 
the upper being about 130 feet long with a fall of 5 feet, and 
the lower 520 feet long with a fall of 8 feet. The cross-section 
is rectangular, being 7.9 feet wide by 3 feet deep. The channel 
is lined with cement mortar, trowel finished, and is in very good 
condition, giving a velocity in the lower section of about 13 feet 
per second. Because of the short length of the upper section it 
was discarded and the lower one chosen for the purpose of exper¬ 
iment, 514.5 feet of which was tested. This flume was built in 
the spring of 1906. 
SOUTH CANAL, U. S. RECLAMATION SERVICE, UN- 
COMPAHGRE PROJECT. Although much of this canal is con¬ 
crete-lined, great difficulty was experienced in selecting suitable 
sections for the purpose of experiment, owing to the short distance 
between curves, and the roughness of the water surface, which ren¬ 
dered an accurate determination of the slope quite difficult. Two 
short sections of heavy grade, and one long one of light grade, were 
finally qhosen as being typical of this type of canal, and as present¬ 
ing the most favorable conditions for determining the hydraulic 
elements. The canal is designed for a carrying capacity of 1,300 
second feet, but the 60 to 100 sec. ft. conveyed at the time of the 
tests is believed to be sufficient to permit of a reasonably accurate 
determination of the frictional resistance for this type of concrete 
lining. The surface of the channel has been left in the condition 
given it by the forms, the boards on the face of which having 
been placed longitudinally in the direction of the channel. The 
concrete lining was placed during 1906 and 1907. 
Two chutes were experimented upon. The one at Mile Post 
No. 2 has a bottom width of 10.1 feet, side slopes 1 to 4, and a grade 
