ity to resist from the horizontal pressure
of the earth.

Mr. Mensch states that "it would take up too much time to prove that the
counterfort acts really as a beam." The writer proposes to show in a
very short time that it is not a beam. A beam is a part of a structure
subject to bending strains caused by transverse loading. This will do as
a working definition. The concrete of the counterfort shown at _b_, Fig.
2, could be entirely eliminated if the rods were simply made to run
straight into the anchoring angle and were connected with little cast
skewbacks through slotted holes. There would be absolutely no bending in
the rods and no transverse load. Add the concrete to protect the rods;
the function of the rods is not changed in the least. M.S. Ketchum, M.
Am. Soc. C. E.,[U] calculates the counterfort as a beam, and the six
1-in. square bars which he uses diagonally do not even run into the
front slab. He states that the vertical and horizontal rods are to "take
the horizontal and vertical shear."

Mr. Mensch says of rectangular water tanks that they are not held
(presumably at the corners) by any such devices, and that there is no
doubt that they must carry the stress when filled with water. A water
tank,[V] designed by the writer in 1905, was held by just such devices.
In a tank[W] not held by any such devices, the corner broke, and it is
now held by reinforcing devices not shown in the original plans.

Mr. Mensch states that he "does not quite understand the author's
reference to shear rods. Possibly he means the longitudinal
reinforcement, which it seems is sometimes calculated to carry 10,000
lb. per sq. in. in shear;" and that he "never heard of such a practice."
His next paragraph gives the most pointed out-and-out statement
regarding shear in shear rods which this voluminous discussion contains.
He says that stirrups "are best compared with the dowel pins and bolts
of a compound wooden beam." This is the kernel of the whole matter in
the design of stirrups, and is just how the ordinary designer considers
stirrups, though the books and reports dodge the matter by saying
"stress" and attempting no analysis. Put this stirrup in shear at 10,000
lb. per sq. in., and we have a shearing unit only equalled in the
cheapest structural work on tight-fitting rivets through steel. In the
light of this confession, the force of the writer's comparison, between
a U-stirrup, 3/4-in. in diameter, and two 3/4-in. rivets tight