( JO ) 
Fifthly , If they are leathered very tight, as to lofe 
no Water, then a great Part of the Engine’s Force is 
deftroyed by the FriStion. 
By fotne Experiments I have accurately made, on 
Engines whofe Parts are large and excellently per- . 
formed, they will lofe f and fometimes j of the calcu- 
lated Quantity. 
However, the Perfeftions or Errors of Engines are 
to be compared together, by the calculated Quantities 
or Forces ; for as they differ in thofe, they will propor- 
tionably differ in their a&ual Performances. 
The Power by which the Wheels are moved. 
The Weight of the Pillar of Water on a Forcer 7 
Inches Diameter, and 120 Foot high. 
7x7 = 49ft The Pounds Averdupoife in 
40 Ya rds high, [a Yard nearly. 
1 960 tt> on one Forcer. 
8 Forcers always lifting. 
The wholeWeight i5’68oft = 1406^.== yTunWeight 
on the Engine at once. 
Then the Crank pulls the Libra 3 Feet from the 
Forcer, and 8,3 Feet from the Center, 
7 Tun 
' - i ■ 
8,3)79.1 (9,? Tun on the Crank. t«». 
Wallower 1,2)9, 5^(4, 3 onTrundle, 
The Spur Wheel 4 
The Radius of the great Wheel 10) 17,2/1,72 Tun. 
20 
The Force on the Floats 18 Ct. 40 lb 34,40 Ct. 
But to allow for Friftion and Velocity, may be reck- 
oned 1 Tun S. 
The 
