724 PROCEEDINGS OF SECTION J. 
14. A variation in cross-section or weight of rolled material of 
more than 2} */ from that specified may be cause for rejection. 
Agreed to by the Keystone Bridge Co., Phenix Bridge Co., 
Union Bridge Co., Edge Moor Iron Co., New Jersey Steel and 
Tron Co., Passaic Rolling Mill Co., Detroit Bridge and Iron 
Works, Morse Bridge Co., Massilon Bridge Co., Cofrode and 
Saylor, John F. Alden, C. J. Schutz, and D. H. Andrews.* 
This American specification is most admirable in its complete- 
ness, and deserving of the highest regard. Next in merit to it J 
place the South Australian and recent New South Wales specifi- 
cations, and the rest, in racing parlance, nowhere. Could the 
American specification be generally introduced into Australian 
practice it would be a very great advantage. I fear, however, its 
elaboration and complication would be objected to by contractors. 
As a concession, therefore, I would suggest a specification more 
on the lines of the late South Australian ones, as follows :— 
For Iron Bripcres, Rours AND SIMILAR STKUCTURES. 
Tendoity, | | | ee ee 
Round, square and flat iron, of 
not more than 4 sq. in. section 50,009 lbs. 18 per cent. 
Angle channel, tee and girder, 
also flats of more than 4 sq. in. 
tection ... a See oe 47,000 lbs. 7 12 per cent. 
Plates under 24 in. wide along 
agit one as ee are 45,000 Ibs. | 8 per cent. 
Plates under 24 in. wide across 
canal ape seh 3 Lae 40,000 lbs. 4. per cent. 
Plates above 24 in. wide along 
nvgehbal © 0h 3- ae a0 ... | 46,000 Ibs. 6 per cent. 
Plates above 24 in. wide across 
erainy er. ais a6 ab 40,000 lbs. | 3 per cent. 
In compiling this proposed set of standards, I have followed 
particulars given by all good authorities accessible to me, checked 
by a number of original experiments of my own, made by means 
of the University testing machine. In adopting elongation rather 
than contraction of area as a measure of ductility, I have been 
guided by the American practice, and also by my own experience, 
which is that elongation can be measured with greater ease and 
% Extracted from “General Specifications for Highway Bridges in Iron and Steel.” By 
J. A. L. Waddell, Consulting Bridge Engineer, Kansas City, Mo., United States, 
