(6i; 
A NEW METHOD OF ESTIMATING STREAM-FLOW L49 
in which R, R h R h R 3 , . . . R l0 are corrections, respectively, to R", R" h R" 2 , R",, 
. . . R"i„ to give the true constants S„ R' h R'*, R',, . . . R' l0 , respectively; 
that is, 
S e = R"+R R' t =R" t +R, R\=R\+R» 
R' 1 = R" 1 +R i R' l = R\+R l R\ a = R\a+R,» 
R' t = R",+R t R\ = R\+R t R' ih =R\ b +R,„ 
R'^R't+R* R' 7 = R%+R 7 R' 10 =R" 10 + R IO 
The v of equation (60) is the same as the v of equation (58). 
It is this form of observation equation, (60), which was used throughout this 
investigation for normal stream-flows in every solution in which it was possible to 
estimate values of S c , R\, R'i, . . . R'i», with any degree of confidence. This 
became possible, in fact, after the very first solution on Stream A. 
The meanings of the r's in equation (60) are here repeated for convenience 
and because they differ slightly from those previously given. 
The current day is the day to which the equation is assigned in listing the 
equations. 
(Obseived rainfall] , ,. , ,. , , JN , , , q., 
r _ \ I I —(estimated evaporation from land) — (observed run-off), on 
1 Net melting current day. Or otherwise stated, 
i\ = (total addition to storage) — (total subtraction from storage), in the drainage 
area on current day, 
= net change in storage on current day. 
r 2 = change in storage on preceding day. 
?- 3 = change in storage on day before preceding day. 
r 4 = change in storage on next preceding two days; (the two days preceding r 3 ). 
r b = change in storage on next preceding 4 days. 
r 6 = change in storage on next preceding 8 days. 
r 7 = change in storage on next preceding 16 days. 
r 8 = change in storage on next preceding 32 days. 
r 9o = change in storage on next preceding 32 days. 
r 9 6 = change in storage on next preceding 32 days. 
?io = change in storage on next preceding 128 days. 
The unit in which n to r 4 inclusive are expressed is 0.01 inch of depth on the 
watershed; r t to r 9fc , 0.1 inch of depth; r 10 , 1.0 inch of depth. 
The sample computations to be given were taken from Solution M, Stream A. 
At the time this solution was made the best available values of C, F, M, T" and 
W 
— were as follows: 
E w 
C=+6.40±0.38 
F= +0.453 ±0.037 
M= +8.39 ±0.015 
T" = 28° F. 
(62) 
