Hooped columns are a patented construction which no one has the right to use without license or instructions from M. Considere, who clearly states that his formulas are correct only for rich concrete and for proper percentages of helical and longitudinal reinforcement, which latter must have a small spacing, in order to prevent the deformation of the core between the hoops.  With these limitations his formulas are correct.

Mr. Godfrey brings up some erratic column tests, and seems to have no confidence in reinforced concrete columns.  The majority of column tests, however, show an increase of strength by longitudinal reinforcement.  In good concrete the longitudinal reinforcement may not be very effective or very economical, but it safeguards the strength in poorly made concrete, and is absolutely necessary on account of the bending stresses set up in such columns, due to the monolithic character of reinforced concrete work.

Mr. Godfrey does not seem to be familiar with the tests made by good authorities on square slabs of reinforced concrete and of cast iron, which latter material is also deficient in tensile strength.  These tests prove quite conclusively that the maximum bending moment per linear foot may be calculated by the formulas, (w l^{2})/32 or (w l^{2})/20, according to the degree of fixture of the slabs at the four sides.  Inasmuch as fixed ends are rarely obtained in practice, the formula, (w l^{2})/24, is generally adopted, and the writer cannot see any reason to confuse the subject by the introduction of a new method of calculation.

WALTER W. CLIFFORD, JUN.  AM.  SOC.  C. E. (by letter).—­Some of Mr. Godfrey’s criticisms of reinforced concrete practice do not seem to be well taken, and the writer begs to call attention to a few points which seem to be weak.  In Fig. 1, the author objects to the use of diagonal bars for the reason that, if the diagonal reinforcement is stressed to the allowable limit, these bars bring the bearing on the concrete, at the point where the diagonal joins the longitudinal reinforcement, above a safe value.  The concrete at the point of juncture must give, to some extent, and this would distribute the bearing over a considerable length of rod.  In some forms of patented reinforcement an additional safeguard is furnished by making the diagonals of flat straps.  The stress in the rods at this point, moreover, is not generally the maximum allowable stress, for considerable is taken out of the rod by adhesion between the point of maximum stress and that of juncture.

Mr. Godfrey wishes to remedy this by replacing the diagonals by rods curved to a radius of from twenty to thirty times their diameter.  In common cases this radius will be about equal to the depth of the beam.  Let this be assumed to be true.  It cannot be assumed that these rods take any appreciable vertical shear until their slope is 30 deg. from the horizontal, for before this the tension in the rod