298 
MOVING FORCJl. 
Cases of diffi- allowed to flow over the perpendicular tube at P, and fill 
cioct^/ne/of another similar perpendicular tube adjoining it, and issue from 
moving force, gjj 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 y, 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 h + 
4g 
(that is = AB + PR,) the 
velocity with which the water issues will be j or 
V 4gh-\-v-. Let V express that velocity, then aV will express 
y® 
the quantity of water which passes in a second j and 2aV — 
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 2 av — 2 «V~for the 
V do; Ag 
iffective moving force of the arm in a second. 
That this is the efl'ective moving force, may be shown also in 
another manner, as follows : 
The aisolule velocity of the water after it has left the 
fV v)* 
machine will be V — v, and L will be the head which 
^g 
would produce that velocity ; which being multiplied by aV, 
(V— y)® 
the quantity of water delivered in a second, gives aV 
4g 
for the moving force which remains with the water after it has 
left the machine. 
If that be deducted from aYh, the whole moving force of the 
water, there will remain a VA — aV for the effective 
moving force, which will be found to be equal to 2dy ^ 
■— 2aV the effective moving force stated above. 
The 
