The professors make also from their economic investigations the following deduction: "The cantilever system hence has no theoretic economy over simple trusses when the piers can be located in any position; moreover, when the influence of the alternating stresses in the anchor arm and the material required for anchor rods are taken into account, it is at a marked disadvantage." This is true for Type A, which is the layout employed by the professors; but it is not correct in general.

The professors are right in their surmise that "probably the common three-span-cantilever bridge has a lower degree of economy than the arrangement where the simple trusses are in the end spans, as in the Kentucky River bridge"; for, as previously stated, Type-C layout requires only from eighty to sixty-five per cent as much metal as does that of Type A, for the same total length of structure. It must be remembered, however, that, as previously indicated, the comparison is hardly fair to the common three-span-cantilever, because the latter provides a greater main opening than that of the alternative layout.