will it be permissible to use angles in tension that are not capable of resisting properly the possible compressive stresses, with due regard for the specified limit of ratio of unsupported length to least radius of gyration.

In cheap highway bridges the lateral diagonals may be made of adjustable rods with right and left clevises at their ends, by which they are to be connected through pins to corner-plates that are riveted to both the lateral strut and the truss member. The ordinary detail consisting of two or three short pieces of angle riveted on top of the cover-plate, and between two of which the rod lies, will not be permitted. Where adjustable rods are employed, the struts to the ends of which they attach must be figured for a total compressive stress equal to the sum of the components (in the direction of said strut) of the greatest allowable working-stresses on all of the adjustable rods meeting at one end of said strut. While this method gives an excessive stress for the strut, the effect will be a desirable error on the side of safety and rigidity.

In designing transverse lateral and overhead struts and their connections, it must be remembered that their main function is to hold rigidly the chords or posts to place and line, and not merely to resist as columns the greatest calculated direct stresses to which they may be subjected. For this reason such struts should have ample section for rigidity, and the connecting plates at their ends should grip both connected members effectively.

Where built stringers are used for the floor system, they shall be made without cover-plates, and generally of the economic depth in respect to total weight of metal, but never less in depth than one fifteenth (1/15) of the span. No splices will be allowed in their flanges nor any in their webs, provided that sufficiently long web-plates are procurable. The compression-flanges shall be made of the same gross section as the tension-flanges, aid they shall be so stiffened that the unsupported length shall never exceed sixteen (16) times the width of flange. Rigid diagonal bracing of angles is to be used between the top flanges of such stringers, unless they be held rigidly  in  place  by  the  flooring;   and  rigid   bracing—frames