THE FLOW OF WATER IN lEEIGATlON CHANNELS, 9 



On the work done by the writer and S. T. Hardmg, wherever the 

 meter was used on a rod the latter rested on a foot piece which in turn 

 rested on the bottom of the channel. For use in wooden flumes a 

 small 4-pronged plug was made to screw up into the rod and project 

 out below the foot piece about 0.01 foot. This was easily forced 

 down into the soft piae or redwood composing the floor and pre- 

 vented the foot from skidding out beneath the meter under the 

 pressure of water. A guy wire made of piano wire was used in high 

 velocities, whether the meter was held on a cable or on a rod. This 

 guy was equipped with a turnbuckle so that it could be adjusted in 

 length and would hold the meter so that the latter took a position in 

 the vertical plane through the front edge of the gauging bridge. 



Meter stations. — ^As it was desirable to measure the discharge in 

 canals near the reaches to be tested for the value of n, it was neces- 

 sary to provide some form of footbridge for small canals and a cable 

 station for canals of such widths that a temporary footbridge was 

 impracticable. For small canals a piece of clear Oregon pine, 2 

 inches by 8 inches, 16 feet long, was found to make the best bridge. 

 It would span a ditch about 14 feet wide without bending appreci- 

 ably under the weight of one man. In a few cases standard wading 

 methods were used. Where ditches were slightly wider than this 

 and quite shallow a light tower of wire-trussed 2 by 2 pieces carried 

 the end of the plank out over the water while measurements were 

 made in the verticals between the bank and about 3 feet from the 

 tower. The plank was then changed to the other side of the canal 

 and the tower placed in the portion of the canal previously measured, 

 and the meter measurements in the verticals resumed. Thus at no 

 time did the meter approach closer than about 3 feet to the tower, 

 and the legs of the latter were so small that but httle water was 

 disturbed by their presence. In order to measure canals up to about 

 90 feet in surface width a portable meter station was provided as 

 follows : 



A rating car was constructed like the body of a fiber steamer 

 trunk. The covering liad no hinges, but was held by trunk fasteners 

 and twin locks, one on each side. When the cover was off iron arms 

 carrying 6-incli sheave wheels and hinged to each end of the car were 

 raised to a vertical position. Coiled in the bottom of the car was 

 carried 130 feet of liigh-grade haulage cable, three-eighth inch in 

 diameter. Steel standards, turnbucklcs, pins, and all other acces- 

 sories also were packed in the car during moves from place to place. 

 This ccjuipraent assembled into a meter station, as shown in Plates 

 DC and Xll.^ 



Hook (jdwjes. — ^Two gauges of the Boydcn type w<iro used for deter- 

 mining the fluctuation in the surface elevation of the water through- 

 out the expcrimentH. Th(;y wore not as well adapted for deter- 



