Lessons 4–8. 2. Mechanical Properties.
Reciprocal actions of rectilinear or sinuous currents parallel or inclined. Reaction of a current on itself.
Reciprocal actions of helices or solenoids. Continuous rotation of currents by their mutual action; by reaction. Analogy of magnets and solenoids. Electro-dynamical theory of magnetism. Action of magnets upon currents and solenoids. Action of currents upon magnets. Experiments of Biot and Savart. Continual rotation of a current by a magnet; of a magnet by a magnet.
Action of the earth upon currents; it acts as a rectilinear current directed from east to west, perpendicularly to the magnetic meridian.
Continual rotation of a current by the action of the earth.
Astatic conductors.
Lessons 9–10. 3. Magnetic Properties.
Action of an interposed conductor upon iron filings.
Electro-magnets. Magnetization temporary or permanent. Principles of the electric telegraph. Electrometers. Reference to diamagnetic phenomena.