On the Telephone. 81 



in 1863 in Dinglei's Polytechnisches journal Vol. 169, p. 29, the 

 following sentence occurs. "Melodies can be reproduced with 

 astonishing certainty, whilst single words, in reading speaking, &c, 

 were less distinct, although the peculiar modulations of the voice 

 in speaking, calling, interrogation, surprise or command were 

 clearly marked." 



The instrument described in this report is somewhat different 

 from the earlier form. The diaphragm was a collodion film and 

 the contact-breaker behind it was lighter and constructed in form 

 of an S shaped lever, the longer arm of which was in contact with 

 the membrane while the shorter made and broke the circuit (Fig 5.) 

 There was no metal disc on the membrane but the circuit was 

 completed by means of the arm on which the lever delicately 

 moved. The receiver, moreover, was a small horse shoe electro- 

 magnet, fixed horizontally to a sounding-board. (Fig. 6.) Here 

 the movement of a light keeper adjusted by a spring before the 

 poles of the magnet reproduced the original sounds. 



In a paper on Reis's improved telephone published in Bottgers 

 Polytechnisches Notizblatt No. 15, 1863, it is stated " Particularly 

 distinct was the reproduction of the scale. The experimenters 

 could even communicate to each other words ; only such however 

 as they had already heard frequently." In confirmation of this 

 may be added the following extract from a recent letter of Dr. 

 Messel to the present writer. " There is not a shadow of doubt 

 about Reis having achieved imperfect articulation, I personally, 

 remember this very distinctly and could find you many other 

 ear-witnesses of the same fact." 



In 1865 a modification in Reis' transmitter was made by Mr. 

 Yeates of Dublin which might have led to important results had 

 it been followed up at the time. A drop of water was introduced 

 between the contact breaker of the transmitter. By this means the 

 current was to some extent rendered a continuous one, the essential 

 feature in a perfect articulating telephone, where gradual variations 

 of the current strength are necessary and not sudden interruptions. 

 Mr. Yeates also independently adopted the electro-magnet form of 

 receiver that Reis had introduced in his later form of telephone. 

 The instrument as modified by Mr. Yeates was shown at a meeting 

 of the Philosophical Society in Dublin in 1865 and the articulation 

 of several words was distinctly heard. But even in this and in 



