Variations of Electrical Conductivity

Nikola Tesla has announced the discovery of a variation in the conductivity of metals and other substances. In making the announcement Professor Tesla endeavors to state as far as possible the apparent conditions of change. He finds that conductivity increases as the conducting medium is elevated above the earth. Capacity for conducting the electrical current is greatest in summer and highest during daylight when the sun is shining. His conclusions are stated as follows: “Taking together the results of my investigations I find that this variation of the capacity and consequently of the vibration period is evidently dependent, first, on the absolute height above sea level, though in a small degree; second, on the relative height of the conducting surface or capacity with respect to the bodies surrounding it; third, on the distance of the earth from the sun, and fourth, on the relative change of the circuit with respect to the sun caused by the diurnal rotation of the earth.” These conclusions, if well founded, will be useful, especially in the conduct of delicate operations or experiments with electricity.