As Professor David Weiss (Cal. State L.A.) noted in 1981, “surely a loudness scale is valuable to a manufacturer of audio equipment”. But how to construct such a scale, describing how loudness depends upon sound-pressure-level? There are no credible empirical loudness measures, so we must employ theory, in which sensation growth is approximated in equations by combining intensity-difference relations (Weber Fractions) with Fechner’s or Ekman’s law for the corresponding sensation differences. In a classic paper, Luce and Edwards claim that three particular intensity-difference relations that they employ not only produce loudness-growth equations, but also exactly return Fechner's Law, upon which they were based. Luce and Edwards are proven wrong, paving the way for more-sophisticated approaches.