_Magneto-Electric Machines._
Current produced by mechanical means--Alternating current--
Magneto-electric machines--Shock produced by interruption of
current--The current must be commutated--Description of
commutator--Current, though alternating in the dynamo, is
continuous in the circuit--Continuous current used for
electro-plating 5
_Dynamo-Electric Machines._
Current will magnetise an iron or steel bar--Permanent magnet--
Electro-magnet--Where the magneto and dynamo machines differ--
Armature of so-called continuous-current dynamo--Type of
commutator--Commutator brushes--Current continuous in the
circuit--Alternating-current dynamos--Current not commutated--
Intense magnetic field produced--Simplicity of Ferranti armature--
Large number of alternations of the current--Alternating current
cannot be used to excite an electro-magnet--Exciter coupled on
to same spindle as dynamo--Power of exciter if used alone 9