And William A.Childs had a third, for lawyers only, in New York, which used dials at first and afterwards printing machines.

These little exchanges had set out to do the work that is done to-day by the telephone, and they did it after a fashion, in a most crude and expensive way.

They helped to prepare the way for the telephone, by building up small constituencies that were ready for the telephone when it arrived.
Bell himself was perhaps the first to see the future of the telephone exchange.

In a letter written to some English capitalists in 1878, he said: "It is possible to connect every man's house, office or factory with a central station, so as to give him direct communication with his neighbors....

It is conceivable that cables of telephone wires could be laid underground, or suspended overhead, connecting by branch wires with private dwellings, shops, etc., and uniting them through the main cable with a central office." This remarkable prophecy has now become stale reading, as stale as Darwin's "Origin of Species," or Adam Smith's "Wealth of Nations." But at the time that it was written it was a most fanciful dream.
When the first infant exchange for telephone service was born in Boston, in 1877, it was the tiny offspring of a burglar-alarm business operated by E.T.Holmes, a young man whose father had originated the idea of protecting property by electric wires in 1858.