Df. Young's Hydraulic Investigations. 
*73 
Table of Coefficients, for English Inches. 
d. 
a . 
• 17 X 
. X 
<o u- 
d. 
a. 
• 1 7 X 
c . 
• 1 7 X 
d. 
a. 
• I? X 
c . 
• l 7 X 
d . 
a 
i 7 X 
X 
OO 
413 
900 
40 
3 8 3 
698 
4 
306 
55 6 
•4 
254 
1 779 
900 
410 
944 
3 ° 
377 
597 
3 
292 
635 
1 
3 
268 
! 9 6 3 
400 
4°9 
948 
2 S 
37 i 
526 
2 5 
284 
694 
•3 
280 
2082 
3 °° 
406 
95 i 
20 
364 
482 
2 
2 77 
774 
4 i 
3°5 
2307 
200 
404 
95 i 
!5 
354 
430 
I -5 
266 
8 94 
.2 
354 
2631 
100 
399 
918 
10 
339 
4 i 3 
1 
2 $i 
io 9 9 
1 
6 
4°9 
2 943 
90 
39 8 
9°3 
9 
33 6 
421 
•9 
248 
1161 
•«5 
447 
3 * 5 ° 
80 
39 6 
885 
8 
33 i 
433 
.8 
2 45 
' 2 34 
1 
T 
466 
3251 
70 
393 
860 
7 
3 2 7 
449 
•7 
2 43 
1322 
JL 
8 
528 
3 5 5 8 
60 
39 1 
825 
6 
3 22 
47 i 
.6 
2 43 
1433 
1 
9 
599 
3866 
5° 
3 8 9 
772 
5 
312 
5°7 
•5 
245 
1578 
.1 
657 
4 l8 3 
II. Of the Resistance occasioned by Flexure in Pipes or Rivers. 
Mr. Dubuat has made some experiments on the effect of 
the flexure of a pipe in retarding the motion of the water flow- 
ing through it ; but they do not appear to be by any means suf- 
ficient to authorise the conclusions which he has drawn from 
them. He directs the squares of the sines of the angles of 
flexure to be collected into one sum, which, being multiplied 
by a certain constant coefficient, and by the square of the 
velocity, is to show the height required for overcoming the 
resistance. It is, however, easy to see that such a rule must 
be fundamentally erroneous, and its coincidence with some 
experiments merely accidental, since the results afforded by 
it must vary according to the method of stating the problem, 
which is entirely arbitrary. Thus it depended only on Mr. 
Dubuat to consider a pipe bent to an angle of 144/ 3 as con- 
sisting of a single flexure, as composed of two flexures of 
72 0 each, or of a much greater number of smaller flexures, 
although the result of the experiment would only agree with 
