se of safety against the
appearance of diagonal tension cracks, or the final failure
produced by them, as compared with straight rods without stirrups,
and that stirrups are so much the more necessary."

Again, with regard to tests made with two concentrated loads, he writes:

"The stirrups, supplied on one end, through their tensile strength,
hindered the formation of diagonal cracks and showed themselves
essential and indispensable elements in the * * * [suspension]
system. The limit of their effect is, however, not disclosed by
these experiments. * * * In any case, from the results of the
second group of experiments can be deduced the facts that the
bending of the reinforcement according to the theory concerning the
diagonal tensile stress * * * is much more effective than according
to the suspension theory, in this case the ultimate loads being in
the proportion of 34: 23.4: 25.6."

It is the speaker's opinion that the majority of the failures described
in Bulletin No. 29 of the University of Illinois Experiment Station,
which are ascribed to diagonal tension, were actually due to deficient
anchorage of the upper ends of the stirrups.

Some years ago the speaker demonstrated to his own satisfaction, the
practical value of vertical stirrups. Several beams were built identical
in every respect except in the size of wire used for web reinforcement.
The latter varied from nothing to 3/8-in. round by five steps. The beams
were similarly tested to destruction, and the ultimate load and type of
failure varied in a very definite ratio to the area of vertical steel.

With regard to the author's seventh point, the speaker concurs heartily
as far as it has to do with a criticism of the usual design of
continuous beams, but his experience with beams designed as suggested by
the author is that failure will take place eventually by vertical cracks
starting from the top of the beams close to the supports and working
downward so as to endanger very seriously the strength of the structures
involved. This type of failure was prophesied by the speaker a number of
years ago, and almost every examination which he has lately made of
concrete buildings, erected for five years or longer and designed
practically in accord with the author's suggestion, have disclosed such
dangerous features, traceable directly to the ideas described in the
paper. These ideas are held by man