studied and toiled to the brink of insanity on general systems or minute parts for which they received neither patent nor recognition. Sometimes a "trick" in the elusive "juice" has been discovered by an obscure laborer whose mind was more active than his hands. All this army of thinkers, experts, and helpers, from such master minds as Edison, Blake, Carty, Pupin, Berliner, Doolittle, Vail and Barton, to the humblest operator, owe their chief incentive to Alexander Graham Bell.
The inventions in Telephony may be grouped into a few great classes. The Case, The Transmitter, The Wiring, and The Switchboard. The last is the greatest achievement of all. "A telephone switchboard is a pyramid of inventions. If it is full grown, it may have two million parts. It may be lit with fifteen thousand tiny electric lamps and served with as much wire as would reach from New York to Berlin. It may cost as much as a thousand pianos or as much as three square miles of farms in Indiana. The ten thousand wire hairs of its head are not only numbered, but enswathed in silk, and combed out in so marvelous a way that any one of them may be linked in a flash to any other." The glory of the switch-board is its merging into the modem Telephone Exchange. "This is the solar plexus of the telephone body. 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 wires could be laid underground or suspended overhead, connected by branch wires with private dwellings and shops, and uniting them with a main cable through a Central Office.'" (Casson, History of the Telephone.)
Turning again from the technical to the practical, the tele-phone is a great means of popular education. Why not? It was born in the private study of a teacher and has been studied in the laboratories of men of science everywhere. As a means of information in which one has a personal interest it far excels the daily newspaper, and the paper itself is made a hundred fold more valuable by its liberal use. Who can estimate what
