CATNEGIE INST. WASH. PUB. 400— FOLSE 
PLATE 20 
~^? 200 I 400 T 
Upper scale: ratio DyP.E. or a/r- 
Lower scale: discharee of stream A in 0.001 cubic foot per second 
Frequency Ratio Curves. 
THE COLUMBIA Pl.ANOGiAPH CO.. WASHINGTON. D C. 
