A telephone switchboard is a device used to connect circuits of telephones to establish telephone calls between users or other switchboards. The switchboard is an essential component of a manual telephone exchange, and is operated by switchboard operators who use electrical cords or switches to establish the connections. The switchboard saw the peak of its use in the 20th century before wider adoption of the electromechanical automatic telephone exchange. The automatic exchange, invented by Almon Strowger in 1888, has replaced most switchboards in central telephone exchanges around the world. Nevertheless, many manual branch exchanges remained operational into the second half of the 20th century in many enterprises. Some establishments, such as the White House, still operate a switchboard. Electronic devices and computer technology have given exchange operators more features. For example, a private branch exchange (PBX) in a business usually has an attendant console, or an auto-attendant function, which bypasses the operator.
History
Following the invention of the telephone in 1876, the first telephones were rented in pairs which were limited to conversation between the parties operating those two instruments. The use of a central exchange was soon found to be even more advantageous than in telegraphy. In May 1877, the Holmes Burglar Alarm Company in Boston, Massachusetts, established by Edwin T. Holmes, installed the first central office and switchboard that served both as a security service at night for banks and businesses, as well as a telephone system. The switchboard operated telephone instruments manufactured by Charles Williams, a licensee of the Alexander Graham Bell company. In January 1878 the Boston Telephone Dispatch company had started hiring boys as telephone operators. Boys had been very successful as telegraphy operators, but their attitude, lack of patience, and behavior was unacceptable for live telephone contact, so the company began hiring women operators instead. Thus, on September 1, 1878, Boston Telephone Dispatch hired Emma Nutt as the first woman operator. Small towns typically had the switchboard installed in the operator's home so that he or she could answer calls on a 24-hour basis. In 1894, New England Telephone and Telegraph Company installed the first battery-operated switchboard on January 9 in Lexington, Massachusetts. Early switchboards in large cities usually were mounted floor to ceiling in order to allow the operators to reach all the lines in the exchange. The operators were boys who would use a ladder to connect to the higher jacks. Late in the 1890s this measure failed to keep up with the increasing number of lines, and Milo G. Kellogg devised the Divided Multiple Switchboard for operators to work together, with a team on the "A board" and another on the "B". These operators were almost always women until the early 1970s, when men were once again hired. Cord switchboards were often referred to as "cordboards" by telephone company personnel. Conversion to panel switch and other automated switching systems first eliminated the "B" operator and then, usually years later, the "A". Rural and suburban switchboards for the most part remained small and simple. In many cases, customers knew their operator by name. As telephone exchanges converted to automatic (dial) service, switchboards continued to serve specialized purposes. Before the advent of direct-dialed long-distance calls, a subscriber would need to contact the long-distance operator in order to place a toll call. In large cities, there was often a special number, such as 211 or 110, which would ring the long-distance operator directly. Elsewhere, the subscriber would ask the local operator to ring the long-distance operator. The long-distance operator would record the name and city of the person to be called, and the operator would advise the calling party to hang up and wait for the call to be completed. Each toll center had only a limited number of trunks to distant cities, and if those circuits were busy, the operator would try alternate routings through intermediate cities. The operator would plug into a trunk for the destination city, and the inward operator would answer. The inward operator would obtain the number from the local information operator and ring the call. Once the called party answered, the originating operator would advise him or her to stand by for the calling party, whom she'd then ring back, and record the starting time once the conversation began.
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