CHAPTER XXII. ELECTROMAGNETISM 158

Electromagnetism.--Exp. 152, To study the lines of force about a straight wire carrying a current.--Ampere's Rule.--Lines of Force About Parallel Wires.--Exp. 153, To study the lines of force about a coil of wire like that upon the galvanoscope.--Exp. 154, To study the magnetic field about a small coil of wire.--Coils.--Polarity of Coils.--Exp. 155, To test the attracting and "sucking" power of a magnetized coil or helix.--Exp. 156, To find whether a piece of steel can be permanently magnetized by an electric current.--Exp. 157, To study the effect of a piece of iron placed inside of a magnetized coil of wire.