FRICTIONAL LOSSES IN INTERNAL COMBUSTION ENGINES. 517 
The change in their slopes occurs at the instant the brake 
is released. 
2:9 
PER SEcOND 
Revs 
a> 10 20-0. 230 40 50 60 
Fic 5. Time in Seconps 
A tangent drawn to the upper curve at the change point 
gave a retardation of °0125 revolutions per second per 
second, and another drawn to the lower curve made the 
retardation at the consecutive instant *002. The brake 
pull was 33’6 Ibs. acting at a lever arm of 3°8 feet, therefore 
ae aoe Oe 
27 (°0125 — °002) 
== US) elo, units. 
