Page:Incandescent electric lighting- A practical description of the Edison system.djvu/71

 Although the dynamos about to be turned on may be running at full speed, and ready as soon as thrown into circuit, by what are known as switches, to generate a current of the proper pressure, they need not necessarily be prepared to generate a large amount of current, for the reason that the field-resistance boxes may be so arranged as to allow only a very small amount of the current generated to pass around the fields; so the couple, when they are finally thrown into circuit, add but little to the amount of current going forth over the line but, as soon as they are fairly working, the attendant by means of the field-resistance boxes of the four dynamos regulates them so as to have each generating its proper portion of the current or, as it is generally expressed, carrying its portion of the load. As the load—that is the number of lights—increases, these four dynamos are brought up as near their full capacity as is desired, and then others are thrown in, and so on, until the station is