PREFACE.

I intend to describe the most important of these phenomena, to show how they may be measured, and to trace the mathematical connections between the quantities measured. Having thus obtained the data for a mathematical theory of electromagnetism, and having shown how this theory may be applied to calculating phenomena, I shall endeavor to clarify the relations between the mathematical form of this theory and that of the fundamental science of Dynamics Dynamics: The branch of mechanics concerned with the motion of bodies under the action of forces.. I do this so that we may be better prepared to determine which kind of physical motions and forces might serve as illustrations or explanations for electromagnetic phenomena.

In describing these phenomena, I will select those that most clearly illustrate the fundamental ideas of the theory, omitting others or saving them until the reader is more advanced.

From a mathematical perspective, the most important aspect of any phenomenon is that it is a measurable quantity. I shall therefore consider electrical phenomena chiefly with a view toward their measurement, describing the methods used and defining the standards on which they depend.

In applying mathematics to calculate electrical quantities, I shall endeavor first to deduce the most general conclusions from the data available to us. Next, I will apply those results to the simplest possible cases. I will avoid, as much as I can, those questions which—though they have demonstrated the skill of mathematicians—have not actually enlarged our scientific knowledge.