DEVELOPMENT OF TELEPHONE SERVICE 429 



Janniar, Joule, Laborde, Legat, Poggendorff, DuMoncel, Delezenne, 

 Ferguson, Paul la Cour, Helmholtz, Gore, Sullivan and others, giving 

 due credit to each. Then he described his undulating current and 

 his electric-speaking telephone, for which letters-patent had been 

 granted, and made it clear to his hearers that the essential factor in 

 this problem was not the devising of a definite form of instrument or 

 tube, nor an apparatus having definite structural peculiarities, nor the 

 combining of a certain number of parts into an operating whole. It 

 was to so cause the electric current to flow that the receiver would not 

 only reproduce a few or a majority or about all of the spoken words 

 that impinged on the diaphragm of the transmitter in the form of 

 sound waves, but would reproduce each and all and every one of the 

 variations in the articulations, loudness and pitch and quality, with all 

 their varying characteristics, whether expressed in the slightest whisper, 

 in the soft voice of the cultured woman, in the sonorous rounded sen- 

 tences of the dignified professor, or in the quick, abrupt remarks of 

 the man of affairs. 



And it may be added that the discovery and practical application 

 of the method so described b} r which the changes in the current 

 strength in a telephone diaphragm were brought about forms the es- 

 sential and underlying principle of every successful electric-speaking 

 telephone designed since Alexander Graham Bell created the art of 

 telephony, a composite art, combining magnetism, electricity, acoustics, 

 phonetics, mechanics and engineering. 



Gardiner Greene Hubbard was in charge of the Massachusetts edu- 

 cational exhibit at the Centennial Exposition. He insisted on placing 

 the primitive telephones on exhibition in that section if no more suit- 

 able place could be secured. Alexander Graham Bell's time was too 

 fully occupied with his professional work to give the subject any atten- 

 tion, and he really did not care whether the telephones were exhibited 

 at the Centennial or not. Class examinations in his school were ap- 

 proaching, and he was far more interested in perfecting the knowledge 

 of the members of his classes who were going forth to instruct deaf 

 children in speech, and speech-reading, than in a mere display of an 

 invention that he had completed, patented and had described in a 

 public lecture. An exhibit meant more or less outlay. He was still 

 in debt to his friends, and the funds to repay his friends must come 

 from the income from his school. Therefore the school would be taken 

 care of to the exclusion of the Centennial. 



Nevertheless, Mr. Hubbard secured some telephones and certain 

 telegraphic instruments, and placed them on a table in the space 

 allotted to the department of education and science of Massachusetts, 

 which occupied a portion of the gallery at the east end of the main 

 building. This modest display was labeled i Telegraphic and Tele- 

 phonic Apparatus. By A. Graham Bell.' It included his system of 

 harmonic telegraphy, and his method of transmitting articulate speech 



