CARNEGIE INST. WASH PUB. 4tt> FOLSE 
PLATE 7\ 
go 
P 
X o 
go 
.•* 
A 
WEIGI 
1TKI) HE 
RATIO 
AN FREC 
IUENCY 
lb 
CURVE 
12 
1 2 3 
RATIO I>'/p.. 
4 
OR a /r 
PROFILES OF DIVIDES 
70 90 110 130 
DISCHARGE D. IN 0.001 C. F. S. 
Mean Frequency Ratio Curve. Cross-Sections of Divides. 
THR COLUMBIA Pl.AF.rx.tArH I 
