work advocated by the highest authorities on the manufacture of structural steel and concurred in by the author, the following may be stated.*

Attention should be paid by designers to the different pound prices for the various sections, and they should remember that these variations are likely to change from time to time. For instance, all angles over 6" and all beams over 15" deep cost a small amount above the base price; and for large plates the extras increase with the widths by a rapidly augmenting scale, starting generally from 100" with a trifling amount and reaching as much as one cent per pound extra for a width of 130". It is, therefore, often more economic to adopt the shallower of two widths and use a little more metal, especially when the variation of an inch or two of girder-depth would change the pound price of the raw material , in the web plates as much as a quarter of a cent. Large differences have existed at times during the past few years, plates sometimes being very expensive and almost unprocurable.

In the design for structural work for all purposes, more consideration should be given by the designer to the sections which are employed. Special material should be avoided, if possible; sections varying by 1/16 inch should be so combined as to use one section as far as practicable; and special sections in small quantities should be eliminated entirely. Very often the delivery on the contract is delayed because the shop has to wait for a small quantity of a special section which is not rolled on time. Compliance with the above will insure better deliveries from the mill and quicker fabrication in the shop; and all parties concerned will be benefited thereby.

When ordering plates, the designer should adhere to standard dimensions as far as possible. This can always be done in the case of lateral and gusset plates, but a special depth may be necessary at times for the webs of stringers or girders. Standard widths for plates are 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 24, 30, 36, and 48 inches.

Eye-bars, adjustable members, turnbuckles, screw-threads, segmental rollers, devices, upsets, etc., should be designed according to the standards of the bridge manufacturers, because quicker deliveries and better fabrication are obtained by the use of standards.

Designs should be made so that all extra or unnecessary operations in the shop are avoided. This should apply particularly to large and heavy members and to small members used in large numbers. The work on these pieces should be kept as simple as possible. When there is an extensive duplication of any piece, it will pay in its designing to save every pound of metal that can legitimately be omitted.

Reaming to templets is useless unless the templets can be set from finished surfaces, as in chord splices, ends of stringers, floor-beam connections, etc. Reaming of laterals to templets is liable to do more harm

* The data for most of the remainder of this chapter were furnished to the author in 1915 for Chapter XVII of "Bridge Engineering" through the courtesy of Messrs. Paul L. Wolfel and Albert F. Reichmann.