— 143 — 
Ilie smallest trussing- bars used should be no less tlniu a quarter of au inch by 
tlu.ee inches, and the bend for attachment should be no less than three inches long ， 
' so as to permit of the use of two staggered rivets. The heavier the trussed bars, 
and the greater the distance between them, the greater should be tlie section of the 
nissing- bars. At the ends of a system of trussing, the bars should be turned and 
Cached, as shown on PI. IX, Fig. 10. 
• The lightest bracket used should bo no weaker than a 2}/ f x 4.9- angle 
uou, which section is to be employed only to attach intermediate struts to posts. 
Where there is uo vertical sway hracing, the stresses on the brackets are to be 
calculated as shown in Chapter IX., and tlie sections are to be proportioned Ly using 
the following table of approximate intensities of working-stress. 
Length of Strut, 
in feet. 
Intensities of 
Working-Stress. 
ずし. 
广 X 3" し 
ih"Xih"L- 
〇" し 
4 
,0 
3.5 
4.o 
4.5 
6 
4.5 
3-0 
3.5 
4,o 
8 
2.0 
2.5 
3.0 
3-5 
The number of rivets that connect the bracket to the lateral strut and post must 
e efficient to transfer all the stress in the bracket to each of these members. 
