The Electric Current: How Produced and how Used

acid action already alternate currents alternate-current ammeter ampères apparatus arc lamp armature arrangement attraction bismuth carbon Cassell's cell charged chemical coils conductor connected consists copper current passes deflection described disc dynamo Edition effect electric current electric pressure electro-magnet electrolytic electromotive force energy experiments field-magnets galvanometer glow lamps heat Illustrated inch increase induction instrument insulated joined junction latter light lines of force liquid loop machine magnetic circuit magnetic field magnetic lines magnetised magnetomotive force measured mechanical metal meter method motor move needle negative number of lines Ohm's law ohms opposite direction ordinary placed plate platinum pole position potential difference produced purpose quantity referred resistance ring rotation round screw secondary batteries shown in Fig side soft iron sulphate supply switch telegraphy temperature terminals thermopile transformers transmitted tube various vertical Vols voltmeter volts whilst wire zinc zinc sulphate