CHAPTER X.--DYNAMOS AND MOTORS 229

DEPENDENCE OF MODERN ELECTRICITY UPON THE DYNAMO -- A FIELD OF FORCE CUTTING ANOTHER FIELD OF FORCE -- VARIETIES OF DYNAMOS -- SIMPLER FORMS OF GENERATORS AND MOTORS -- HOW TO MAKE A UNI-DIRECTION CURRENT MACHINE -- PERMANENT MAGNET, ARMATURE, SHAFTS, WHEELS, ETC. -- A SMALL DYNAMO -- MACHINES TO LIGHT LAMPS, RUN MOTORS, ETC. -- A SPLIT-RING DYNAMO -- A SMALL MOTOR -- THE FLAT-BED MOTOR -- MOTORS OF OTHER TYPES