A distinctive problem of high building construction is the provision for lateral resistance to wind pressure. Unless the building is more than four times its width in height, the effect of the wind pressure is not a serious consideration. The danger of overturning the building bodily is very remote, the chief danger being a tendency to shear the connections or twist and distort the frame. Sometimes the ordinary framing of the floors and columns will be sufficient, and in other cases special provision must be made. This is done by diagonal ties where the construction will allow, as shown in Fig. 227. "When the spaces between the columns must be used for passage or for windows, knee braces and deep girders are used, as in Fig. 228, and portal bracing is sometimes adopted, but to no great extent. (Fig. 229.)

Fig. 226. Spandrel Beam.

Fig. 226. Spandrel Beam.

Inspection

Steel and iron members are inspected in the mill, the shop, and on the job. Mill inspection is to determine the quality of the steel, while shop inspection relates to the preparation of the members.

It is necessary to see that the drawings are accurately followed, and the work properly assembled, that the quality of work is up to the standard, riveted tightly and accurately done. The members must be straight and free from twists or bends, punching sharp and true, with the holes in the different pieces exactly opposite. Column ends and all bearing surfaces true and at right angles to the axis. All portions not accessible after putting together must be painted before being assembled.