That which is condemned in the seventh point is not so much the calculating of reinforced concrete beams as continuous, and reinforcing them properly for these moments, but the common practice of lopping off arbitrarily a large fraction of the simple beam moment on reinforced concrete beams of all kinds.  This is commonly justified by some virtue which lies in the term monolith.  If a beam rests in a wall, it is “fixed ended”; if it comes into the side of a girder, it is “fixed ended”; and if it comes into the side of a column, it is the same.  This is used to reduce the moment at mid-span, but reinforcement which will make the beam fixed ended or continuous is rare.

There is not much room for objection to Mr. Thacher’s rule of spacing rods three diameters apart.  The rule to which the writer referred as being 66% in error on the very premise on which it was derived, namely, shear equal to adhesion, was worked out by F.P.  McKibben, M. Am.  Soc.  C. E. It was used, with due credit, by Messrs. Taylor and Thompson in their book, and, without credit, by Professors Maurer and Turneaure in their book.  Thus five authorities perpetrate an error in the solution of one of the simplest problems imaginable.  If one author of an arithmetic had said two twos are five, and four others had repeated the same thing, would it not show that both revision and care were badly needed?

Ernest McCullough, M. Am.  Soc.  C. E., in a paper read at the Armour Institute, in November, 1908, says, “If the slab is not less than one-fifth of the total depth of the beam assumed, we can make a T-section of it by having the narrow stem just wide enough to contain the steel.”  This partly answers Mr. Thacher’s criticism of the ninth point.  In the next paragraph, Mr. McCullough mentions some very nice formulas for T-beams by a certain authority.  Of course it would be better to use these nice formulas than to pay attention to such “rule-of-thumb” methods as would require more width in the stem of the T than enough to squeeze the steel in.

If these complex formulas for T-beams (which disregard utterly the simple and essential requirement that there must be concrete enough in the stem of the T to grip the steel) are the only proper exemplifications of the “theory of T-beams,” it is time for engineers to ignore theory and resort to rule-of-thumb.  It is not theory, however, which is condemned in the paper, it is complex theory; theory totally out of harmony with the materials dealt with; theory based on false assumptions; theory which ignores essentials and magnifies trifles; theory which, applied to structures which have failed from their own weight, shows them to be perfectly safe and correct in design; half-baked theories which arrogate to themselves a monopoly on rationality.