TRANSMISSION OF ELECTRICAL ENERGY 207 



(Fig. 9) which is divided into two sections: the machine 

 panels, and the feeder panels. The machine panels are 

 equipped with ammeters, with the switches necessary for 

 regulating, and with voltmeters for measuring the electrical 



FIG. 93. A Switchboard. 



energy generated. The feeder panels have similar instruments 

 for controlling the output of energy to the various circuits. 

 The operator in charge of the switchboard is able to tell by 

 a glance at these instruments the amount of work each 

 machine is doing, and thereby to know when it is advisable 

 to throw out of or put into operation additional machines. 

 A rheostat is furnished for each generator so that the pres- 



