I. Electric field in a conducting medium. 1. Coulomb’s law and theory of a constant electric field. 2. Electric field and steady current in a conducting medium. 3. The electric field, current density, and potential in a conducting medium. II. Electric methods of surface geophysics. 4. Electric soundings. 5. Interpretation of electric soundings. 6. Methods of electrical profiling and mapping. III. Electric methods of borehole geophysics. 7. Electric methods of borehole geophysics