on it during erection, although, as before stated, it is not sufficiently reliable for resisting the effects of live loads.

The best method of attaching the suspended span of an ordinary cantilever bridge is by hangers from inclined end posts on the cantilever-arms. For such suspenders narrow eye-bars should be used; and it is generally better to hinge them at the middle. This is because they are subjected to transverse bending, due to longitudinal expansion and contraction of suspended span from both changes of temperature and the application and removal of the live load. Narrow bars can spring slightly without being overstrained, and a rotation of the eyes on the pins will thus be prevented. Such a rotation would eventually enlarge the eyes and cut notches into the pins, necessitating for some future time expensive repairs.

A suspended span thus hung is free to move longitudinally under thrust of train, but its ends are tightly held in a lateral direction, so that all wind loads are carried properly to the bottom chords of the cantilever-arms; and excessive longitudinal motion is prevented by the continuity of the track.

In cantilever-arms it is better and more economical to use inclined posts as well as vertical ones over the piers, so that the various loads will be carried more directly to the masonry. To insure the travel of the wind stresses down the transverse bracing between these inclined posts, instead of up to the apex of the top chord and down the bracing between the vertical posts, the author leaves out one pair of diagonals of the upper lateral system between the said apex and the tops of the inclined posts. The same expedient is used also for the anchor-arms and between the hips of the suspended span and the cantilever-arms.

All bracing between opposite vertical posts and between opposite inclined posts should be made very rigid; and in double-track structures all the sway-bracing should be proportioned to carry as a live load, with the proper allowance for impact, the greatest shear which can come upon it from loading one side of the floor only.

Great care is necessary in designing the pedestals over the