CHAPTER VII.--ELECTRICAL RESISTANCE 125

GOVERNING THE ELECTRIC CURRENT -- OHM’S LAW -- RESISTANCE-COILS AND RHEOSTATS -- HOW TO MAKE SIMPLE APPARATUS -- LIQUID RESISTANCE -- IMPORTANCE OF SWITCHES -- USES OF A HOUSE-CURRENT -- RUNNING A SEWING-MACHINE, FAN, OR TOYS -- AN EASY METHOD FOR A BOY’S USE