These supervisory signals took the form of lamps and were placed on the keyboard in positions immediately adjacent to the associated cords.
The supervisory lamp associated with the peg in the wanted subscriber's jack glows from the time that the peg is inserted until the subscriber responds, when it darkens, in which condition it remains until the subscriber restores the receiver to the hook and causes the lamp to light up again.
The other supervisory lamp on the cord circuit is controlled in a similar manner by the subscriber who originated the call, and as that subscriber's telephone is off the hook when the peg is inserted, the lamp is not lighted at all until the subscriber replaces the receiver.
An elaborate organization is required to keep a complete check and record of all the goods entering and leaving the station, to ensure that they are loaded into the proper wagons according to their destination, that they are unloaded and sorted in such a way that they can be delivered to their consignees with the least possible delay, that they are not stolen or accidentally mislaid, &c.; and accommodation must be provided for a large clerical and supervisory staff to attend to these matters.
The Board of Control of State Institutions has supervisory and inquisitorial powers over all county and private institutions in the state in which insane are kept, and over homes for friendless children maintained by societies or institutions.
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