where W is the total transverse load in pounds on the piece, including impact, and l is the length of the piece in inches.

The extreme fibre-stress for the combination shall not exceed sixteen thousand (16,000) pounds; and the moment at mid-panel is to be assumed the same in amount as that at the panel points.

Top chords subjected to transverse loading should be made as deep as economy of metal will permit.

BENDING ON INCLINED END POSTS.

In proportioning inclined end posts of trusses of through-bridges for a combination of all the loads herein specified, together with the bending caused by the wind-pressure which travels transversely down the piece to the pier or abutment, the extreme fibre may be strained thirty (30) per cent higher than the intensity specified for the direct compression, the bending moment being computed on the assumption that the inclined end post is fixed above by the portal bracing and at the bottom by its connections to the pedestal and end floor-beam, thus making the lever-arm of the moment equal to one half the length of that portion of the inclined end post lying between the centre of pedestal-pin and the centre of the lower portal strut (or, in case of plate-girder portals, the bottom of the said plate girder).

BENDING DUE TO WEIGHT OF MEMBER.

If the extreme fibre-stress resulting from the bending due to the weight only of any member does not exceed ten (10) per cent of the specified intensity of working-stress, the effect of such bending may be ignored; but, if it does so exceed, its effect must be combined with those of the other stresses, using, however, for determining the sectional area, an intensity of working-stress ten (10) per cent greater than that specified.