It is seldom, indeed, that both legs are connected. In order to settle the question of the necessity for this requirement, the author has had made, in connection with his Northwestern Elevated work, a series of tests to destruction of full-sized members of open-webbed girders, attached in the testing machine as nearly as practicable in the same way as they would be attached in the structure. It was intended to settle by these tests the following points: first, effect of connecting by one leg only; second, effect of eccentric connection; and, third, the ultimate strength of star struts with fixed ends, each of these struts being formed of two angles. As these tests are not yet finished, their results cannot be given here. The principal deduction to be made from the tests thus far completed is that an equal-legged angle riveted by one leg only will develop about 75% of the strength of the entire net section, while a 6" X 3 1/2" angle riveted through the longer leg will develop about 90%. It is therefore more economical for short diagonals to use unequal-legged angles connected by the longer leg than to employ supplementary angles to try to develop the full strength of the piece. In fact, the experiments made up to date indicate that these supplementary angles will not strengthen the diagonal essentially. However, further experiments may show the contrary.

IV.   FAILURE TO PROPORTION TOP CHORDS OF
OPEN-WEBBED, LONGITUDINAL GIRDERS TO RESIST BENDING FROM WHEEL
LOADS IN ADDITION TO THEIR DIRECT COMPRESSIVE STRESSES.

This neglect is common enough in the older structures, and the fault is a serious one, although the stiffness of the track rails and that of the ties tend to distribute the load and thus reduce the bending.

V.   INSUFFICIENT BRACING ON CURVES.

Too often in the older structures the curved portions of the line are no better braced than are the straight portions. A substantial system of lateral bracing on curves extending over the entire width of the structure and carried well into the tops of the columns adds greatly to the rigidity of the structure, and, consequently, to the life of the metal-work.

VI.   INSUFFICIENT BRACING BETWEEN ADJACENT
LONGITUDINAL GIRDERS.

The function of the bracing between longitudinal girders is an important one, for it is the first part of the metal-work to