Page:Incandescent electric lighting- A practical description of the Edison system.djvu/73

 operation is repeated as day draws on, until the entire station is at rest.

That the operations just described should be intelligently and carefully performed, is of the greatest importance, as each lamp when burning represents a given amount of coal being consumed at the station; and as the light is sold at a predetermined and stated price, just as gas is, it is necessary, in order to have the electric light company's books balance in favor of the proper parties, that no coal should be burned unless the light is in actual use. This can be accomplished only by reducing the outgoing current as rapidly as it can safely be done when the lights are turned off, and increasing it only as fast as is absolutely necessary when lights are being turned on; for, the greater the current win<j^ forth, the more dynamos in operation, the larger the number of engines required to run them, the more steam at a given pressure must be furnished to the engines, and the more coal