SEVENTY-FIVE YEARS OF THE TELEPHONE 217 



vision of the telephone and his precepts and practices in following it have 

 guided the scientists and engineers who have followed him and still live in 

 the expansion of his activities in these Laboratories which bear his name. 

 Before moving into this evolution of devices, methods and technology, 

 it should be recalled that Bell's vision covered not only the devices which 

 he invented and which formed the basis of telephony, but extended also to 

 the manner of providing a communication system extending throughout the 

 land. While in England in 1878 Bell wrote: 



''...it is conceivable that cables of telephone wires could be 

 laid underground, or suspended overhead, communicating 

 by branch wires with private dwellings, country houses, shops, 

 manufactories, etc., etc., uniting them through the main cable 

 with a central office where the wires could be connected as de- 

 sired, establishing direct communication between any two places 

 in the city. Such a plan as this, though impracticable at the pres- 

 ent moment, will, I firmly believe, be the outcome of the intro- 

 duction of the telephone to the public. I believe, in the future, 

 wires will unite the head offices of the Telephone Company in 

 different cities, and a man in one part of the country may com- 

 municate by word of mouth with another in a distant place. . . . 

 Believing, however, as I do, that such a scheme will be the ultimate 

 result of the telephone to the pubhc, I will impress upon you all 

 the advisability of keeping this end in view, that all present arrange- 

 ments of the telephone may be eventually reaUzed in this grand 



system "^^^ 



In Bell's prophetic conception of the telephone system, it is evident that 

 there was then in his mind a reaUzation of the invention and development 

 that would be required beyond his work on the telephone itself to make pos- 

 sible the kind of communication system which he envisioned. In "keeping 

 this end in view," there has been a continuing activity over the years to 

 make Bell's telephone perform better and better to meet the requirements 

 of the "grand system." An important factor from this standpoint was em- 

 bodied in Bell's hquid transmitter. It has been the continued development 

 of the variable resistance transmitter that has made available at the talker's 

 position a thousand-fold amplification of the small amount of energy in 

 speech sounds. This has made it possible to use lower cost, smaller wires 

 in the extensive network connecting private dwellings, shops, manufactories 

 and central offices as contemplated by Bell. 



For the "outside plant" and "central office" portions of Bell's 1878 con- 



^"^ This and other information about the early years of the telephone are taken from 

 the well documented book "Beginnings of Telephony" by F. L. Rhodes. Item 1 in Bibliog- 

 raphy at end of this article. 



