242 On the Measure of 
~ would stand at P, PR being if. Now if 
instead of letting the water escape at C, it 
be allowed to flow over the perpendicular tube 
at P, and fill another similar perpendicular 
tube adjoining it, and issue from an orifice at 
the bottom of that tube, the effect must be 
the same as if it issued at C, and a moving 
force must be expended at C, sufficient to 
generate the velocity v, in the water which 
passes, and also to raise it from R to P. 
The pressure at C being equal to the 
weight of a column of water whose height is 
ht, (that is =AB+PR), the velocity 
. 5 . . . 
with which the water issues will be 
“ps Ge) or V4gh+v*. Let V ex- 
press that velocity, then aV will express the 
quantity. of water which passes in a second ; 
v* . . 
and 2aV dg will express the moving force 
necessary to generate the velocity v, in that 
quantity of water, and to raise it from R to P. 
That quantity of moving force being deducted 
from the total moving force of the arm, leaves 
Vv 2 2 
2av (i £59) -- chit Ps for the effective 
moving force of the arm in a second. 
