The golden section and the ground resistance

In the Fifties´ of the last century, Italian and North American Authors explained that the systematic error α_A on the measurement of the ground resistance, related to the close distance D of the auxiliary current electrode B, can be offset, during the measurement, leading the voltage probe at a distance, with respect to the test grounding system A, equal to 0.618·D, when A and B can be considered as punctiform electrodes with respect to their distance. This paper gives the explanation of physical meaning of the 0.618 method and demonstrate that we´re dealing with golden section. The paper points out the unclear or incorrect aspects of the traditional treatment.