TOS)’/ 3 
12 Mr. Vince's Experiments on the Resistance 
was totally at a loss to conjecture to what circumstance this 
difference of results was owing. By repeating however the 
experiments, and observing at what point of the line xmz the 
centre of the stream acted, I discovered that the effect varied 
by varying that point ; that it was greatest when the stream 
struck the lever as near as it could to x ; less when it struck it 
at the middle m ; and least when it struck it as near as it could 
to z, notwithstanding the stream acted at the same perpendi- 
cular distance from the axis in each case, and the parallel part 
of the force always acted in the line x m z. At the angles 8o°, 
70°, 6 o°, the fluid striking as near as it could to the edge z, 
gave the lever a motion, not in the direction xmz, but in the 
opposite direction z m x, as appeared by taking away the scale. 
I have therefore marked such results with the sign , the 
motion produced being then in a direction opposite to that 
which ought to have been produced, by that part of the force 
of the stream which acts parallel to the plane of the lever. The 
forces which are here put down, are those which take effect in 
a direction parallel to the plane of the lever, for every tenth 
degree of inclination ; the perpendicular force being 1 oz. 
17 dwts. i2grs. 
At 8o° inch 
At 70® inch 
At 6 o ° inch 
"Edge z 
Middle m 
.Edge x 
Edge z 
Middle m 
.Edge x 
Edge z 
Middle m 
Edge x 
dwts. grs. 
0 % 
3 
3 
V 7/ 
3 
10 
17 
'ffy 
3 
6 
2 
X 
11 
10 
'htb 
7 
11 
J 0^ 63 
C 3 
* A A /? 
- iJ 
7 ' 
if 
