He said that he had been struck with the idea that the greater or less duration of a musical sound might represent the dot and dash of the telegraphic alphabet, and it occurred to him that simultaneous telegraphic transmissions, of which the number should only be limited by the delicacy of the sense of hearing, might be obtained by suitable combinations of long and short sounds, and that these should be effected by a keyboard of tuning-forks applied to one end of a telegraphic line, and so arranged as to react electrically on electro-magnetic instruments striking on the strings of a piano. For this purpose it would be necessary to assign an employé to each of the keys for the service of transmission, and to arrange that his correspondent should only distinguish his peculiar note among all those transmitted. It was this idea, Mr. Bell adds, which led to his researches in telephony. For several years he sought for the best mode of reproducing musical sounds at a distance by means of vibrating rheotomes: the best results were given by a steel plate vibrating between two contacts, of which the vibrations were electrically produced and maintained by an electro-magnet and a local battery. In consequence of its vibration, the two contacts were touched alternately, and the two circuits were alternately broken; the local circuit which kept the plate in vibration, and the other which was connected with the line, and reacted on the distant receiver, so as to effect simultaneous vibrations in it. A Morse key was placed in the latter circuit near the sending instrument, and when it was lowered, vibrations were sent through the line; when it was raised, these vibrations ceased, and it is easy to see that, by lowering the key for a longer or shorter time, the short and long sounds necessary for the different combinations of telegraphic language could be obtained. Moreover, if the vibrating plate of the receiving instrument were so regulated as to vibrate in unison with the sending instrument in correspondence, it would vibrate better with this sender than with another whose plate was not so adjusted. It is evident that different sounds might be simultaneously transmitted with several plates by this arrangement of contact breaker, and that at the receiving station the sounds might be distinguished by each employé, since the one which corresponds to the fundamental note of each vibrating plate is reproduced by that plate. Consequently, the sounds produced by the vibrating plate of _do_, for example, will only be audible at the receiving station on the plate tuned to _do_, and the same will be the case with the other plates; so that the sounds will reach their destination, if not without confusion, yet with sufficient clearness to be distinguished by the employés.