y that their shearing strength may
be utilized; where such conditions do not obtain, it is not ordinarily
necessary to count on the shearing strength of the rods.

_Point 5._--Even if vertical stirrups do not act until the concrete has
cracked, they are still desirable, as insuring a gradual failure and,
generally, greater ultimate carrying capacity. It would seem that the
point where their full strength should be developed is rather at the
neutral axis than at the centroid of compression stresses. As they are
usually quite light, this generally enables them to secure the requisite
anchorage in the compressed part of the concrete. Applied to a riveted
truss, the author's reasoning would require that all the rivets by which
web members are attached to the top chord should be above the center of
gravity of the chord section.

_Point 6._--There are many engineers who, accepting the common theory of
diagonal tension and compression in a solid beam, believe that, in a
reinforced concrete beam with stirrups, the concrete can carry the
diagonal compression, and the stirrups the tension. If these web
stresses are adequately cared for, shear can be neglected.

The writer cannot escape the conclusion that tests which have been made
support the above belief. He believes that stirrups should be inclined
at an angle of 45 deg. or less, and that they should be fastened rigidly to
the horizontal bars; but that is merely the most efficient way to use
them--not the only way to secure the desired action, at least, in some
degree.

The author's proposed method of bending up some of the main bars is
good, but he should not overlook the fact that he is taking them away
from the bottom of the beam just as surely as in the case of a sharp
bend, and this is one of his objections to the ordinary method of
bending them up. Moreover, with long spans and varying distances of the
load, the curve which he adopts for his bars cannot possibly be always
the true equilibrium curve. His concrete must then act as a stiffening
truss, and will almost inevitably crack before his cable can come into
action as such.

Bulletin No. 29 of the University of Illinois contains nothing to
indicate that the bars bent up in the tests reported were bent up in any
other than the ordinary way; certainly they could not be considered as
equivalent to the cables of a suspension bridge. These beams behaved
pretty well, but the loads were applied so as to make them practi