tion,
at least not to any great extent, until a diagonal crack has formed,"
but, in connection with this statement, the following quotations must be
read:

"The tests were planned with a view of determining the amount of
stress (tension and bond) developed in the stirrups. However, for
various reasons, the results are of less value than was expected.
The beams were not all made according to the plans. In the 1907
tests, the stirrups in a few of the beams were poorly placed and
even left exposed at the face of the beam, and a variation in the
temperature conditions of the laboratory also affected the results.
It is evident from the results that the stresses developed in the
stirrups are less than they were calculated to be, and hence the
layout was not well planned to settle the points at issue. The
tests, however, give considerable information on the effectiveness
of stirrups in providing web resistance."

"A feature of the tests of beams with stirrups is slow failure, the
load holding well up to the maximum under increased deflection and
giving warning of its condition."

"Not enough information was obtained to determine the actual final
occasion of failure in these tests. In a number of cases the
stirrups slipped, in others it seemed that the steel in the
stirrups was stretched beyond its elastic limit, and in some cases
the stirrups broke."

"As already stated, slip of stirrups and insufficient bond
resistance were in many cases the immediate cause of diagonal
tension failures, and therefore bond resistance of stirrups may be
considered a critical stress."

These quotations seem to indicate much more effectiveness in the action
of vertical stirrups than the author would lead one to infer from his
criticisms. It is rather surprising that he advocates so strongly the
use of a suspension system of reinforcement. That variety has been used
abroad for many years, and numerous German experiments have proved with
practical conclusiveness that the suspension system is not as efficient
as the one in which vertical stirrups are used with a proper
arrangement. An example is the conclusion arrived at by Moersch, in
"Eisenbetonbau," from a series of tests carried out by him near the end
of 1906:

"It follows that with uniform loads, the suspended system of
reinforcement does not give any increa