812 



SCIENCE. 



[N. S. Vol. XII. No. 308. 



THE TELEPHONO GRAPH* 



The telephonograph is a combination of the 

 phonograph with the telephone, and is intended 

 to take and record telephone messages by auto- 

 matic means, and, to a limited extent, give an 

 answer in the same way. It is the invention 

 of Mr. J. E. O. Kumberg, and an example of 

 the instrument is to be seen at the office of 

 Messrs. H. F. Joel and Co., 31 Wilson street, 

 Finsbury. The combination is simple in gen- 

 eral principle, but some ingenious mechanism 

 has been introduced to make the working effec- 

 tive. The message is spoken by the person 

 sending it into the telephone in the usual way, 

 and the vibrations set up by the voice are 

 caused to act upon a recording stylus by the 

 impact of the sound-waves. In this way the 

 wax cylinder in the office of the person spoken 

 to is indented and a phonogram is produced. 

 This, of course, can be read off at leisure in the 

 usual way. The vibrations are transmitted 

 either directly or indirectly, in the latter case 

 an electrical current effecting the object. A 

 highly-sensitive transmitter of any well-known 

 form is used. If it is desired, the instrument 

 may be so arranged that two wax cylinders, or 

 phonogi-ams, may be inscribed, the one being 

 in the office of the sender, to be retained as a 

 record, and the other, an exact duplicate of the 

 first, being produced in the office of the re- 

 ceiver. To effect this end, the transmitter in- 

 strument has two channels or tubes for the 

 sound-waves produced by speaking into the 

 mouthpiece. One of these channels leads to 

 the speaking or recording diaphragm of the in- 

 strument at the transmitting station, which en- 

 graves them upon the phonogram blank. At 

 the same time identical sound waves are elec- 

 trically conveyed to the receiving instrument 

 at the distant station of the person spoken to, 

 and are there imprinted on another phonogram 

 blank. It is possible to throw the phonograph 

 action out of play and use the telephone in the 

 ordinary way. 



Neither the telephone nor the phonograph is 

 perfect in its action, and unpracticed persons 

 are apt at times to experience some difficulty in 

 translating the sounds either one or the other 



* From the London Times. 



produces into articulate speech ; and when the 

 deficiencies of the two are combined difficulty is 

 still more likely to arise, although proficiency 

 is retained to a remarkable degree by practice. 

 In order to overcome this defect a special de- 

 sign of recording diaphragm cell has been de- 

 vised by the inventor. It consists of a double 

 cell micro-diaphragm having two compart- 

 ments, one of which is fitted with a multiple, 

 or other suitable microphone diaphragm disc, 

 and the other with a sensitive disc of glass. 

 This receives the undulations produced by the 

 sound-waves and communicates them to the 

 recording stylus. Below the glass diaphragm 

 is a guard, which serves to confine the sound, 

 and also as a shield against the scraping noise 

 which the stylus makes by cutting into the wax 

 cylinder. One of the most important features 

 of the invention is a floating weight controlled 

 by a spring which is attached by means of a 

 pivoted lever and a fine wire to the two discs, 

 already mentioned, of the double cell micro- 

 diaphragm. The pivoted lever carries the re- 

 cording and reproducing tools by which the 

 sound vibrations are respectively engraved upon 

 or reproduced from the wax cylinder. The ac- 

 tion of the weight is to give additional power, 

 or perhaps, rather, additional certainty and 

 steadiness to the reproducing tools. Such 

 weights have before been used to supply what 

 may be described as a fly-wheel effect, thus 

 enabling the cutting tool to overcome any irreg- 

 ularities in the composition of the wax. The 

 weight, however, is apt to rebound through its 

 own momentum, and thus defeat the end for ■ 

 which it is provided. To overcome this defect 

 a spiral spring is fitted in the machine under 

 notice, with the result that the jumping or vi- 

 bratory motion is damped. It is claimed that 

 by this device a deeper cut is made in the wax 

 cylinder than has been before obtained, and the 

 reproduction of the sound waves is thereby 

 made more perfect. 



We lately had an opportunity of testing this 

 invention to the extent of transmitting a mes- 

 sage from one room to another adjoining, al- 

 though the length of wire represented a consid- 

 erable distance. As reproduced by means of 

 the phonogram, on which the message was re- 

 corded, the words were distinctly audible, the 



