Dr. Young’s Hydraulic Investigations. 
169 
Observers. 
d. 
l. 
h. 
V. 
Dub. 
Log. 
rat. 
Y. 
Log. 
raL 
a. 
c. 
Gerstner, 
at 5 5 . i; 0 F. 
.2 
6 3 
10.7 
24.2 
2 3-9 
.006 
24 1 
.002 
349 
2 533 
7-7 
21.0 
199 
.023 
19.1 
.042 
4-7 
15.8 
14,9 
.026 
139 
.056 
*•7 
7-5 
8.2 
•039 
6.9 
.036 
•7 
2.5 
5.0 
301 
3 4 
•133 
•*33 
33 
10.7 
27.1 
2 3-4 
.064 
22.5 
.081 
488 
3 2 59 
7-7 
23 2 
19.4 
•°77 
18.5 
.098 
4-7 
15.4 
14.6 
.024 
J 3'5 
.058 
i -7 
5.6 
8.1 
.160 
6.7 
.078 
•7 
2 3 
4.6 
.301 
3-4 
.169 
.0674 
33 
10.7 
10.0 
89 
.051 
10. 1 
.004 
975 
57 °° 
7-7 
7 - 2 
7-4 
.012 
8.2 
•°57 
4-7 
4-5 
5.6 
■°95 
5.6 
.095 
i -7 
M 
3 -> 
.316 
2 -5 
.222 
•7 
•5 
1.8 
•444 
1. 1 
• 34 2 
. 
(Mean 
.129— 
:L.i-346 .098- 
rL.1.254) 
Y. At 6o°. 
_1 
4 2 
8 50 
3 2 '4 
1440 
0 
CO 
1 3 - 3 6 
.032 
2956 
N 
OO 
OO 
CO 
1 
18 3 
3 - 4 2 
3 °-° 
•53 
.52 
008 
1 1404452100 
1.17 
5.8 
.27 
1 
• 3 ° 
.046 
(Mean .029=: 
L. 1.068) 
Dubuat 
2 
255.25 
36-35 
86.31 
84.2 
.01 1 
79-7 
•°35 
287 
747 
1 
24 
36.25 
122.59 
1 17.8 
.018 
120.8 
.007 
2 59 
1063 
27 
106.45 
IOI.l 
.022 
104.1 
.010 
18 
84 85 
82.2 
.013 
84.8 
.000 
9 
59-25 
57-5 
.013 
597 
.004 
4 
27.08 
1 18 67 
1 1 1.5 
.027 
1 18.5 
.000 
(Mean 
11 
q 
L. 1.041 
II 
Os 
O 
O 
L. 1.022) 
It appears from this comparison, that in the forty experi- 
ments extracted from the collection, which served as a basis 
for Dubuat’s calculations, the mean error of his formula 
is - r - of the whole velocity, and that of mine ~ only ; but 
if we omit the four experiments, in which the superficial 
velocity only of a river was observed, and in which I have 
calculated the mean velocity by Dubuat’s rules, the mean 
MDCccvin. Z 
