190 APPLIED MECHANICS 
the area of the cross section of the bar if the maximum stress ba . 
one-fourth of the maximum stress. due to the above. fluctuating load load 
12. Piston aan raetia Fig 2 the nian yrs? 254, p. 130, en 
in the table on p. 181-and in 254, gr ing the results on separate d 
as follows :—(1) Annealed bars ; (2): » group bars; (3) bars quenched in w 
(4) bars quenched in oil. Show also on each diagram the results of the t 
the bars as received from the rolls. Scales.—Carbon, 1 inch to 0-2 per ¢ 
stress, 1 inch to 10 tons per square inch; elongation, 1 inch to 10 
Examine all the results carefully, and discuss the effects of the different J ci 
heat treatment on the different steels. oe 
