Innocenzo Manzetti was a prolific Italian inventor, and born in the town of Aosta on March 17, 1826. Among his inventions were:
- a flute-playing automaton, built in 1849. It was stylized in the shape of a man, seated in a chair with flute in hand. Inside the chair were levers and tubes which made the automaton’s fingers move on the flute keys. It was wound like a clock and could perform twelve different arias.
- a set of geodetic instruments that were used for his work as a land surveyor.
- a bicycle and piano.
- a wooden flying parrot which began by beating its wings, then slowly rising in the air and hovering for two or three minutes.
- a hydraulic machine to empty water from the wells of the Ollomont mines.
- a steam-powered car.
- a telephone model, made in 1864, called telegraphe parlant (speaking telegraph). It was never patented nor presented at conferences or described in the newspapers.
Although Manzetti never published information regarding the device, his friends did. Here, in part, is the English translation of the text published by the petit Journal of Paris, written by the lawyer Emile Queland of the Paris Imperial Court:
“A new discovery immensely fruitful in its possible applications both in the fine arts, as well as the industries, is going to augment the marvels of this century; and this is the transmission of the sounds and of the spoken words by telegraph. . . Manzetti transmits directly the word by means of the ordinary telegraphic wire, with an apparatus simpler than the one which is now used for dispatches.”
The only technical description of Manzetti’s invention came from Dr. Pierre Dupont, a friend of the inventor. His description was undated, although friends maintain it was written in 1861:
“The speaking telegraph consisted of a funnel-shaped cornet in which was placed, transversally, an iron lamina, in the shape of a very thin plate. This plate easily vibrated under the impulsion of the sound waves coming from the bottom of the funnel. In the cornet, where was also a magnetized steel needle, running inside a bobbin, vertically placed with respect to the vibrating lamina and very close to the same.
“From the bobbin or spindle started a silk-coated copper wire, the other end of which was connected to a bobbin placed in an apparatus identical to that described above. From this second apparatus started another electric wire, which was connected to join the former. Now, if in the vicinity of the lamina of one of the cornets a sound was emitted, this sound was immediately reproduced by the lamina in the other cornet.
“The communication between the laminae of the two cornets took place thanks to the principle that the vibrations of an iron plate in front of a pole of a piece of magnetized iron product electric currents, the duration of which is the same as that of the motion of the vibration lamina.
“In a word, the acoustic waves produced by speech, voice, sound into a cornet were transformed in the apparatus into electric waves, and then transformed back into acoustic waves in the other cornet.”
It would seem that the description seems to refer to a “make-and-break” telephone transmitter and magnetostriction receiver. In both cases, we have a needle as a magnetic core against which an iron plate vibrates. The vibration causes the needle to brush the plate. Unfortunately, the “brushing” causes the circuit to be either open or closed — the variable resistance required to transmit voice is not there.
Manzetti died in Aosta on March 17, 1877, on the exact day of his 51st birthday.