6 
The Colorado Experiment Station 
in the center of the channel was measured with a graduated hard¬ 
wood stick, having a beveled edge. By use of plumb bob and 
tape the mean length of wetted chord was determined, and having 
k—- sf.ra' -> 
measured the semi-circular arc of the flume, the wetted perimeter 
was determined by measuring the dry arcs directly with the tape. 
These elements, viz., diameter, semi-circular arc, dry arc, wetted 
perimeter, wetted chord and maximum depth of water, when fitted 
together diagramatically, determined the form of curve assumed 
