Most of this newspaper article directly quotes Nikola Tesla's announcement.
The Daily News, Sault Sainte Marie, Michigan, Tuesday Afternoon, February 5, 1901.
Nikola Tesla Says Capacity
Varies With Absolute Height
Above Sea Level.
Nikola Tesla announced the other day another new discovery in electricity. This time it is a new law, and by reason of it, Mr. Tesla asserts, a large part of technical literature will have to be rewritten. Ever since anything has been known about electricity scientific men have taken for granted that the capacity of an electrical conductor is constant. When Tesla was experimenting in Colorado, he found out that this capacity is not constant, but variable. Then he determined to find out the law governing this phenomenon. He did so, and all this he explained to the New York Sun. Here is what he said:
"It is well known that an electric circuit comports itself like a spring with a weight attached to it. Such a spring vibrates at a definite rate, which is determined by two quantities, the pliability of the spring and the mass of the weight. Similarly an electric circuit vibrates, and its vibration, too, is dependent on two quantities, designated as electrostatic capacity and inductance. The capacity of the electric circuit corresponds to the pliability of the spring and the inductance to the mass of the weight.
"The importance of these observa-
"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 facts may be of particular interest to meteorologists and astronomers, inasmuch as practical methods of inquiry may result from these observations, which may be useful in their respective fields. It is probable that we shall perfect instruments for indicating the altitude of a place by means of a circuit properly constructed and arranged, and I have thought of a number of other uses to which this principle may be put.