30 
A NEW METHOD OF ESTIMATING STREAM-FLOW 
Table 11. — Computation of (r^r: —2.6), Lake Michigan-Huron 
Date 
Val 
w 
lies of — — , midnight to midnight, 
30th meridian time 
Mean 
\100 / 
Chicago 
Mil- 
waukee 
Grand 
Haven 
Green 
Bay 
Es- 
canaba 
Sault 
Ste. 
Marie 
Alpena 
Port 
Huron 
Parry 
Sound 
Sau- 
geen 
Mid- 
night 
to 
mid- 
night 
Noon 
to 
noon 
1910 
Sept. 1 
2 
3 
4 
6 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
Oct. 1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
3.2 
2.3 
2.7 
2.0 
3.7 
4.0 
2.5 
3.4 
3.0 
2.0 
4.0 
3.7 
1.7 
0.8 
1.0 
1.4 
2.9 
1.8 
0.7 
1.0 
2.7 
3.3 
2.0 
4.6 
1.5 
3.1 
3.2 
1.7 
2.3 
4.4 
3.0 
3.0 
4.7 
3.3 
2.6 
2.1 
1.2 
2.3 
1.3 
1.2 
2.9 
2.4 
2.0 
2.4 
2.2 
2.2 
2.1 
2.2 
2.2 
2.4 
3.3 
3.9 
2.9 
1.5 
1.9 
2.5 
3.0 
4.0 
1.7 
1.5 
2.7 
2.7 
3.5 
3.7 
1.5 
3.5 
2.1 
1.5 
2.0 
2.9 
2.3 
4.4 
3.3 
1.7 
2.0 
2.3 
2.4 
2.9 
2.3 
1.8 
2.0 
1.7 
2.0 
1.9 
2.6 
2.6 
1.6 
2.8 
2.6 
1.9 
3.3 
3.4 
2.2 
1.3 
1.4 
2.0 
3.5 
3.2 
1.6 
1.7 
2.3 
2.0 
2.1 
4.2 
1.8 
2.3 
4.2 
1.2 
1.8 
3.8 
3.7 
2.5 
4.1 
3.1 
3.0 
2.6 
1.9 
3.5 
2.4 
1.9 
2.2 
2.2 
1.4 
1.7 
2.7 
2.5 
2.1 
2.6 
2.1 
2.1 
2.9 
3.8 
1.2 
1.8 
1.5 
2.2 
3.2 
3.7 
1.3 
1.5 
2.0 
1.9 
4.7 
3.5 
1.3 
2.0 
3.2 
1.7 
1.9 
3.0 
2.9 
2.4 
3.1 
1.3 
2.8 
2.3 
3.0 
3.4 
1.9 
2.3 
1.1 
2.3 
1.4 
1.3 
3.1 
2.1 
1.9 
2.7 
2.0 
3.0 
3.3 
3.7 
1.9 
1.7 
1.7 
2.3 
3.7 
3.5 
2.1 
1.5 
3.1 
2.7 
4.4 
4.2 
1.0 
2.4 
2.5 
2.2 
2.3 
2.6 
3.4 
2.8 
3.5 
1.4 
2.5 
1.9 
3.7 
3.4 
2.4 
2.8 
1.3 
1.3 
2.0 
0.7 
1.6 
2.5 
1.3 
3.3 
3.3 
1.4 
1.5 
2.7 
1.2 
1.6 
0.8 
1.4 
1.9 
1.9 
1.2 
1.8 
2.0 
2.4 
2.2 
3.1 
2.5 
1.7 
3.8 
1.6 
1.4 
1.6 
5.0 
1.8 
3.0 
1.0 
2.7 
2.8 
1.8 
3.0 
3.3 
1.6 
2.0 
2.6 
2.2 
1.4 
3.5 
2.6 
2.0 
3.0 
3.3 
2.1 
2.8 
3.0 
1.7 
2.1 
1.9 
1.8 
2.6 
2.9 
2.7 
1.9 
2.4 
3.8 
2.8 
5.4 
2.3 
2.9 
3.3 
1.7 
2.7 
3.1 
4.6 
2.6 
4.4 
1.7 
3.1 
3.0 
3.0 
2.7 
3.5 
2.2 
3.3 
2.1 
2.1 
1.5 
1.7 
3.0 
1.6 
2.4 
3.3 
1.7 
1.8 
3.3 
4.0 
1.6 
1.7 
1.2 
2.0 
2.4 
1.5 
1.3 
2.4 
2.2 
1.0 
2.7 
1.9 
1.8 
2.9 
1.5 
1.5 
2.8 
3.9 
2.0 
3.2 
3.6 
2.8 
4.2 
1.5 
2.3 
3.7 
2.2 
1.9 
1.9 
1.0 
0.7 
2.2 
1.9 
1.4 
2.2 
2.6 
1.2 
1.2 
1.7 
1.7 
1.2 
1.0 
0.7 
1.2 
3.1 
1.4 
1.4 
1.7 
1.4 
1.7 
2.9 
1.9 
1.2 
3.8 
2.2 
1.2 
2.2 
4.6 
1.0 
3.1 
3.1 
2.2 
2.2 
0.2 
2.2 
2.2 
1.2 
1.7 
1.7 
2.6 
1.4 
1.7 
3.6 
1.9 
3.1 
4.3 
1.7 
1.4 
2.6 
2.9 
1.9 
2.2 
1.7 
2.9 
2.4 
1.7 
1.2 
1.9 
1.7 
2.2 
2.9 
2.2 
0.7 
4.1 
2.4 
1.7 
3.4 
6.7 
2.2 
3.6 
3.8 
3.1 
4.1 
1.0 
2.6 
4.3 
2.2 
2.2 
2.0 
1.9 
1.5 
2.5 
2.7 
1.8 
2.8 
2.9 
2.0 
2.6 
3.2 
2.1 
1.6 
1.5 
1.7 
2.7 
2.9 
1.6 
1.5 
2.3 
2.4 
2.7 
3.7 
1.8 
2.2 
3.3 
1.8 
1.9 
3.0 
4.0 
2.5 
3.6 
2.4 
2.7 
2.8 
2.0 
2.8 
2.7 
1.9 
2.1 
2.0 
1.7 
2.0 
2.6 
2.2 
2.3 
2.8 
2.4 
2.3 
2.9 
2.6 
1.8 
1.6 
1.6 
2.2 
2.8 
2.2 
1.6 
1.9 
2.4 
2.6 
3.2 
2.8 
2.0 
2.8 
2.6 
1.8 
2.4 
3.5 
3.2 
3.0 
3.0 
2.6 
2.8 
2.4 
2.4 
2.8 
2.3 

+0.2 
+0.3 
0.0 
+0.2 
0.0 
+0.6 
+0.2 
+0.2 
0.0 
+ 0.9 
+0.6 
+ 0.4 
+0.4 
0.0 
+0.2 
+0.2 
EXAMPLE OF COMPUTATION OF U, LAKE MICHIGAN-HURON 
The quantity, I 3 , for Lake Michigan-Huron, is the computed rise of the surface 
of that lake due to the inflow into it from Lake Superior through St. Mary's River. 
This flow is given by equation (3) in 0.001 foot of depth on Lake Michigan-Huron in 
terms of the elevation of the water surface above mean sea-level, at the S. W. Pier 
(above locks), Sault Ste. Marie. In Table 12 is shown the computation of 7 3 for 
the dates September 1 to October 10 inclusive, 1910. The first column shows the 
water levels as observed by the U. S. Lake Survey, and the second the discharge of 
the St. Mary's River to the nearest 0.001 foot of rise of Lake Michigan-Huron, com- 
puted by simple substitution in equation (3). Throughout the period May to 
