In 1874, M. La Cour sent audible signals from Fredericia to Copenhagen, by means of a tuning-fork, a contact-piece, a telegraphic wire, and a key to set the fork in vibration. Mr Elisha Gray appears to have made a more definite advance in this direction. He has transmitted the pianoforte sounds of a concert through the wire of an electric telegraph. The performer played at Philadelphia, to an audience at New York, ninety miles distant. The apparatus may be called a telephonic piano; it transmits the sounds of that instrument, but of no other. Public performances of this kind were given in the early months of the present year. On one evening the instrument was played at Chicago, and the music heard at Milwaukee, eighty-seven miles distant. _The Last Rose of Summer_, _Yankee Doodle_, _The Sweet By-and-by_, and _Home, Sweet Home_ are named as the tunes thus played. On a second occasion the apparatus triumphed over a distance of no less than two hundred and eighty-four miles, from Chicago to Detroit; not much was attempted in actual music, but the sounds were audible at this great distance. Two instruments are required, a transmitter and a receiver. There is a keyboard of two octaves (available therefore only for simple melodies), a tuning bar, an electro-magnet, and an electric circuit. The play on the keys with the fingers produces vibrations, thuds, molecular movements, in rhythmical succession; these are transmitted by the electric wire to the receiving apparatus at the other end. This receiving apparatus is a large sounding-box, on which is mounted an electro-magnet. The box intensifies the sounds by its sonorousness, through the medium of the slight touches which the magnetised iron gives to the box at every expansion or elongation which the electro-magnetism gives it. Delicate experiments have shewn that there is a minute difference in the length of a bar of iron when magnetised and demagnetised; and Mr Gray appears to have taken advantage of this property in causing his magnetised bar to give a succession of taps to the resonant box. We believe that the apparatus requires wholly new setting for each tune. If so, the system bears the same relation to real pianoforte playing as the barrel organ does to the church organ; it does not lend itself to the spontaneous or extempore effusions of the player.