154 
A NEW METHOD OF ESTIMATING STREAM-FLOW 
depth per day on the watershed by multiplying by 10.7; column (11), the total loss 
from watershed, or the sum of columns (9) and (10); column (12), r lf or column (2) 
minus column (11). Column (12) appears in "Example of Observation Equations 
for Normal Stream-Flow," and also in the "Example of Computation of —D," 
already given. 
The vapor-pressures and e are expressed in 0.01 inch of mercury; the wind 
velocity in miles of movement per day; t in degrees F; and all the other quantities 
in 0.01 inch of depth. 
Table 41 
— Example of 
computation of 
n 
Date 
Observed 
mean 
rainfall 
Observed 
mean air 
tempera- 
ture 
Observed 
mean 
vapor 
pressure 
Satura- 
tion 
vapor 
pressure 
e 
0.319e 
Mean 
wind 
move- 
ment 
Evapora- 
tion from 
land, Ei 
Observed 
run-off 
Total 
loss 
u 
1913 
June 1 

51 
17 
37 
+20 
6 
77 
14 
2 
16 
-16 
2 

52 
18 
39 
+ 21 
7 
86 
16 
2 
18 
-18 
3 

52 
15 
39 
+ 24 
8 
71 
18 
2 
20 
-20 
4 

60 
16 
36 
+ 20 
6 
63 
14 
2 
16 
-16 
5 

46 
18 
31 
+ 13 
4 
70 
9 
2 
11 
-11 
6 

46 
18 
31 
+ 13 
4 
65 
9 
2 
11 
-11 
7 
51 
44 
16 
29 
+ 13 
4 
68 
9 
2 
11 
+40 
8 
23 
41 
20 
26 
+ 6 
2 
55 
5 
2 
7 
+ 16 
9 
36 
43 
22 
28 
+ 6 
2 
37 
5 
2 
7 
+29 
10 
60 
41 
24 
26 
+ 2 
1 
60 
2 
2 
4 
+56 
11 
8 
40 
15 
25 
+ 10 
3 
58 
7 
2 
9 
- 1 
12 
39 
36 
14 
21 
+ 7 
2 
69 
5 
2 
7 
+32 
13 

44 
17 
29 
+ 12 
4 
46 
9 
2 
11 
-11 
14 

50 
17 
36 
+ 19 
6 
66 
14 
2 
16 
-16 
15 

53 
18 
40 
+22 
7 
60 
16 
2 
18 
-18 
16 
1 
51 
18 
37 
+ 19 
6 
61 
14 
2 
16 
-15 
17 
16 
46 
23 
31 
+ 8 
3 
59 
7 
2 
9 
+ 7 
18 
16 
47 
31 
32 
+ .1 

42 

2 
2 
+ 14 
19 
1 
61 
25 
37 
+ 12 
4 
53 
9 
2 
11 
-10 
20 

51 
21 
37 
+ 16 
5 
63 
12 
2 
14 
-14 
21 

50 
24 
36 
+ 12 
4 
63 
9 
2 
11 
-11 
22 

47 
23 
32 
+ 9 
3 
50 
7 
2 
9 
- 9 
23 
14 
46 
22 
31 
+ 9 
3 
62 
7 
2 
9 
+ 5 
24 

49 
23 
35 
+ 12 
4 
54 
9 
2 
11 
-11 
25 

53 
15 
40 
+25 
8 
60 
18 
2 
20 
-20 
26 

56 
13 
45 
+32 
10 
75 
23 
2 
25 
-25 
27 
8 
55 
14 
43 
+29 
9 
78 
21 
2 
23 
-15 
28 
16 
51 
30 
37 
+ 7 
2 
68 
5 
2 
7 
+ 9 
29 

50 
24 
36 
+ 12 
4 
60 
9 
2 
11 
-11 
30 

52 
15 
39 
+24 
8 
67 
18 
1 
19 
-19 
From the values of r t shown in column (12), and copied in as coefficients of Ri 
in the sample of observation equations for normal stream-flow for June 1913, it is 
possible to verify the computations of certain of the other r's there shown according 
to the definitions previously given. As an illustration, take the observation equa- 
tion for June 30, 1913. The computation of the r's is as follows: 
Ti— — 19, computed as shown above. 
r t = r l for June 29, =—11. 
r, = ri for June 28, =r, for June 29 = +9. 
r< = 2 (r,, for June 26 and 27) = -25-15 = 
= 2 (r, for June 28 and 29). 
-40. 
