Failure commenced through giving way of angle irons, beginning in a fine seam in the first bend of the lower flange from the end support, the seam being along the root of the angle, which continual pressure tore apart across the angle as shown, when the web commenced to tear like a sheet of paper, in direction and manner as exhibited on plate herewith--from photograph. From some cause not apparent the deflections were not similar at the symmetrical end rams, _a_, the point where the web failed--left side--being sharply deflected. While the angles showed root fracture at the opposite point, the web did not fail or show indications of so doing, the deflection being on an easy curve. With the extreme yielding of the lower flange angles, the angle brackets connecting girder with posts commenced to go, tearing likewise along the root, and stripping the heads from the extreme upper rivets as shown. The internal diaphragm connecting the channel sides of the posts was unaffected. The rivets connecting the ruptured flange with web appeared as perfect as when driven, and no indication was disclosed, as far as it was possible to tell, of the holes in the web elongating or any upsetting of bearing surface. There is no telling what the web and rivets would have borne had not the solid angle irons given way at the first bend. It is to be noted that flange plate with leg of angle attached thereto was intact, showing no indication of rupture. _Discussion._--Taking that stage of the experiment when a permanent set was first noted--viz., 1/32 inch--the recorded load was 532,500 lb., or as near as may be 3-1/3 times the basis on which the calculations in the first part of this paper were made--40,000 lb. on each stringer, or 160,000 lb. total. Applying this ratio to the preceding computations, the iron would be apparently strained as follows: { _m_ 3,800 × 3-1/3 = 12,600 lb. per square inch (psi). Flanges at { _a_ 5,700 × 3-1/3 = 19,000 psi. { _b_ 6,400 × 3-1/3 = 21,200 psi. Web. { Between _a_ and _b_, 2,600 × 3-1/3 = 8,700 lb. per square inch. { At least section, 8,000 × 3-1/3 = 26,600 psi. { Post attachment: { Bearing area, 6,600 × 3-1/3 = 22,000 lb. per square inch. { Single shear, 5,000 × 3-1/3 = 16,600 psi. Rivets. { Web and flange connections, end rivets: { Bearing area, 20,000 × 3-1/3 = 66,600 psi. { Double shear, 5,800 × 3-1/3 = 19,300 psi.