Telephone Number (started utilizing)

In the late 1870s, the Bell interests started utilizing their patent with a rental scheme, in which they would rent their instruments to individual users who would contract with other suppliers to connect them; for example from home to office to factory. Western Union and the Bell company both soon realized that a subscription service would be more profitable, with the invention of the telephone switchboard or central office. Such an office was staffed by an operator who connected the calls by personal names. Some have argued that use of the telephone altered the physical layout of American cities.