456 Mr. T. Tate on a Siphon Electrometer. 
t : sith : 
but = = ne on the assumption that the velocities are uniform, 
1 
eee a) 
e = Z e 
Now by experiment we have 
ni=n,t,, and .. —=-; 
e Uu n : e 
= — aa > 
Uy Ny 
that is, the discharge being constant, the dynamic effects are in the 
ratio of the squares of the number of revolutions of the machine. 
If n=20, and n,;=10, as in Exp. III., then i that is, in 
this case the dynamic effects will be as 1 to 4, or a double num- 
ber of revolutions produces a quadruple effect. 
Let x be put for the number of revolutions of the machine (its 
state being constant) performed in 60 seconds, or 1 minute, to 
produce the same discharge as 7 revolutions in ¢ seconds; then 
nt 
x x 60=nt, or <= 60" 
Similarly, we have for the relation of equal discharge corre- 
sponding to any other state of the machine, 
ately 
re GOR 
Now it may be presumed that the efficiency of the machine is 
inversely proportional to the number of revolutions per minute 
requisite to produce a given discharge; but we find 
pc WALL 
x nt ” 
that is, the efficiency of a machine varies inversely as the product 
of the number of revolutions by the corresponding time requisite to 
produce a gwen discharge. 
ff 7775, then TERR 
that is, im this case the efficiency of a machine varies inversely as 
the number of revolutions (the time being constant) requisite to 
produce a given discharge. 
Thus, if a machine discharges half of a cubic inch of water in 
twenty revolutions in a certam time, and another machine dis- 
charges the same amount of water in ten revolutions in the same 
time, then the latter machine will have double the power of the 
former. 
