Telegraph Switchboard

a device installed in a telegraph office for connecting telegraph equipment, lines, and channels. A telegraph switchboard is connected to all incoming and outgoing lines and channels and to the telegraph equipment in the office where it is installed. It is used by telegraph office attendants to switch the route of communications lines expeditiously during normal operation and to replace faulty lines or channels in the event of failure. Instruments installed in the switchboard may be used to determine the electrical characteristics of telegraph lines and channels. The switchboard is also equipped with lightning-protection devices, such as fuses and lightning arresters.