Mr. Thacher criticises the fifth point as follows: 

“Vertical stirrups are designed to act like the vertical rods in a Howe truss.  Special literature is not required on the subject; it is known that the method used gives good results, and that is sufficient.”

This is another example of the logic applied to reinforced concrete design—­another dogmatic statement.  If these stirrups act like the verticals in a Howe truss, why is it not possible by analysis to show that they do?  Of course there is no need of special literature on the subject, if it is the intention to perpetuate this senseless method of design.  No amount of literature can prove that these stirrups act as the verticals of a Howe truss, for the simple reason that it can be easily proven that they do not.

Mr. Thacher’s criticism of the sixth point is not clear.  “All the shear from the center of the beam up to the bar in question,” is what he says each shear member is designed to take in the common method.  The shear of a beam usually means the sum of the vertical forces in a vertical section.  If he means that the amount of this shear is the load from the center of the beam to the bar in question, and that shear members are designed to take this amount of shear, it would be interesting to know by what interpretation the common method can be made to mean this.  The method referred to is that given in several standard works and in the Joint Committee Report.  The formula in that report for vertical reinforcement is: 

V s
P = --------- ,
j d

in which P = the stress in a single reinforcing member, V = the proportion of total shear assumed as carried by the reinforcement, s = the horizontal spacing of the reinforcing members, and j d = the effective depth.

Suppose the spacing of shear members is one-half or one-third of the effective depth, the stress in each member is one-half or one-third of the “shear assumed to be carried by the reinforcement.”  Can Mr. Thacher make anything else out of it?  If, as he says, vertical stirrups are designed to act like the vertical rods in a Howe truss, why are they not given the stress of the verticals of a Howe truss instead of one-half or one-third or a less proportion of that stress?

Without meaning to criticize the tests made by Mr. Thaddeus Hyatt on curved-up rods with nuts and washers, it is true that the results of many early tests on reinforced concrete are uncertain, because of the mealy character of the concrete made in the days when “a minimum amount of water” was the rule.  Reinforcement slips in such concrete when it would be firmly gripped in wet concrete.  The writer has been unable to find any record of the tests to which Mr. Thacher refers.  The tests made at the University of Illinois, far from showing reinforcement of this type to be “worse than useless,” showed most excellent results by its use.