B. H. Chirgwin & C. W. Kilmister 
Steady Electric Fields and Currents [PDF ebook] 
Elementary Electromagnetic Theory

Steady Electric Fields and Currents, Volume 1 is an introductory text to electromagnetism and potential theory. This book starts with the fields associated with stationary charges and unravels the stationary condition to allow consideration of the flow of steady currents in closed circuits. The opening chapter discusses the experimental results that require mathematical explanation and discussion, particularly those referring to phenomena that question the validity of the simple Newtonian concepts of space and time. The subsequent chapters consider steady-state fields, electrostatics, dielectrics, energy theorems, and uniqueness theorems. The concluding chapter examines the steady flow of electric currents in closed circuits. Undergraduate students with electromagnetism course will greatly benefit from this book.