Joseph McKenna

“ Those which have that shape are sustaining walls only, and were so obviously unfit for use as retaining walls that no one seems to have seen the utility for that purpose, of which the form, when properly adapted and strengthened, was capable. There is also a prior wall, wholly of metal, fairly disclosing a unitary heel adapted to hold the wall erect; but to see that this could become merely a skeleton imbedded in concrete may well have required, in 1898, more than ordinary vision. ”

“ If the prior art had shown a structure intended for a retaining wall, and having a heel such that the weight of the earth thereon would tend to keep the wall erect, it might be difficult to find invention in merely adding the form of reinforcement most suitable to create the desired tensile strength ”

“ And it is said that the patented wall, 'having more base and less weight' than such other shapes, 'will rest more securely on a soft or yielding foundation, the weight of the material resting on the heel' causing the latter 'to press on the earth below, and thus cause friction to prevent the whole wall from sliding outward.' This is the especial effect of the patent, achieved by the wall of the shape described, and distinguishes it, is the contention, from the retaining walls of the prior art. ”