s the
method given by the writer. It would standardize design as methods using
the coefficient of elasticity cannot do.

Professor Clifford, in commenting on the first point, says, "The
concrete at the point of juncture must give, to some extent, and this
would distribute the bearing over a considerable length of rod." It is
just this local "giving" in reinforced concrete which results in cracks
that endanger its safety and spoil its appearance; they also discredit
it as a permanent form of construction.

Professor Clifford has informed the writer that the tests on bent rods
to which he refers were made on 3/4-in. rounds, embedded for 12 in. in
concrete and bent sharply, the bent portion being 4 in. long. The 12-in.
portion was greased. The average maximum load necessary to pull the rods
out was 16,000 lb. It seems quite probable that there would be some
slipping or crushing of the concrete before a very large part of this
load was applied. The load at slipping would be a more useful
determination than the ultimate, for the reason that repeated
application of such loads will wear out a structure. In this connection
three sets of tests described in Bulletin No. 29 of the University of
Illinois, are instructive. They were made on beams of the same size, and
reinforced with the same percentage of steel. The results were as
follows:

Beams 511.1, 511.2, 512.1, 512.2: The bars were bent up at third points.
Average breaking load, 18,600 lb. All failed by slipping of the bars.

Beams 513.1, 513.2: The bars were bent up at third points and given a
sharp right-angle turn over the supports. Average breaking load, 16,500
lb. The beams failed by cracking alongside the bar toward the end.

Beams 514.2, 514.3: The bars were bent up at third points and had
anchoring nuts and washers at the ends over the supports. Average
breaking load, 22,800 lb. These failed by tension in the steel.

By these tests it is seen that, in a beam, bars without hooks were
stronger in their hold on the concrete by an average of 13% than those
with hooks. Each test of the group of straight bars showed that they
were stronger than either of those with hooked bars. Bars anchored over
the support in the manner recommended in the paper were nearly 40%
stronger than hooked bars and 20% stronger than straight bars. These
percentages, furthermore, do not represent all the advantages of
anchored bars. The method of failure is of greatest significance. A
failu