78 



Professor Barrett, 



wax a little strip of platinum, corresponding to the hammer of the ear, 

 and which closed or opened the electric circuit, precisely as in the instru- 

 ments of a later date. The receiving instrument was a knitting needle 

 surrounded with a coil of wire and placed on a violin to serve as a sound- 

 ing board. It astonished everyone quite as much as the more perfect 

 instruments of Bell now do. 



"The instrument I have described has now passed into the hands of 

 the Telegraph Department of the German Government." 



The paper referred to in the foregoing letter is contained in the 

 annual report of the Physical Society of Frankfort-on-Main for 

 the year 1861. It is entitled " Telephony by means of electric 

 currents" for the word telephone is first suggested by Reis in 

 this paper as the name of his instrument. The transmitter is 

 shown in fig. 3, instead of a cork a cubical wooden block is used 

 with a conical orifice closed at the smaller end by a membrane. 



The accompanying diagram, fig. 4, shows the principle of Reis's 



Fig. 3. 



Keis's early form of Transmitter. 

 _ Line, 

 Fig 



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