246 On the Measure of 
water from C to P,,CR=AB will represent 
that part of it which is expended in producing 
change of figure. The greatest velocity, 
therefore, that the orifice, when the machine 
meets with no resistance, can acquire, will be 
VERE. 
When the velocity of the orifice is less than 
that, V will be greater than v; and V—v, the 
absolute velocity of the water after it has left 
the machine, will be V.8 (4gh4v7)—v. The_ 
head or the moving force expended in produc- 
ing that velocity will be v.8 (4gh+v* )—v) 
| 4g 
- The moving force expended in produc- 
ing change of figure will be a(t ‘ ) 
Now when the sum of these two quantities, or 
pei Mery wee 
v8 (Agh+v* )—v) +a( mt) is a mi- 
ag ; 
nimum, we shall find v=/2gh(y¥5—1)= 
6.3056vV 7 for the velocity of the orifice when 
the machine produces a maximum of effect ; 
and in that case the above sum becomes 
=.4472h. 
~ We shall therefore have h—.4472h=.5528h 
for the maximum of effect, supposing / te 
