HEARING THROUGH WIRES: Antonio Meucci
Thomas Edison, after him, most nearly imitated Meucci’s methods. Meucci searched by trial and error at times when reason alone brought no fruit. It was, after all, an accident which revealed the teletrofonic principles to him. Providence itself in action.
TELETROFONO
Meucci methodically explored different means for vibrating electric current with speech. From 1850 to 1862 he developed over 30 different models, with twelve distinct variations. His first models utilized the vibrating copper loop principle which he discovered in Havana. Paper cones were replaced with tin cylinders to increase the resonant ring. He experimented with thin animal membranes, set into vibration by contact with the vibrating copper strip. This model begins to resemble the familiar form of the telephone as we know it.
Meucci wrapped fine electromagnetic bobbins around his copper electrodes, increasing vocal amplitudes considerably. In a second series, he explored the use of magnetic vibrators. A great variety of loops, coils, soft-iron bars, and iron horseshoes appear in Meucci’s successive designs. These latter models gave amazingly loud results. In addition, Meucci’s diagrams reveal experimentation with both separate and “in-line” copper diaphragms. These latter operated by the yet to be discovered “Hall Effect”, where current-carrying conductors vibrate more strongly in magnetic fields produced by their own currents.
While power for his early teletrofonic system was derived from large wet cell batteries in the basement, Meucci made a pivotal discovery, discovered when he grounded his lines with large dissimilar metal plates. Suddenly, his system operated as if large batteries had been added to the line. Meucci disconnected the basement batteries and the system continued to operate, powered by ground currents alone.
This use of buried dissimilar plates repeatedly appears throughout early telegraphic patents. The actual devices by which this astounding electrification of lines was established were called “earth batteries”. Several significant individuals made remarkable discoveries while developing earth batteries throughout the latter 1800’s. They found that the earth batteries were not really generating the power at all.
Earth batteries tap into earth electricity and draw it out for use. Some telegraphic lines continue to operate well into the 1930’s with no other batteries than their ground endplates. Certain systems continued using their original earth batteries without replacement in excess of 40 years!
Earth batteries are intriguing because they seem never to corrode in proportion to the amount of electrical power which they generate. In fact, they scarcely corrode at all. Exhumed earth batteries showed minimal corrosion. A mysterious self-regenerative action takes place in these batteries, a phenomenon worthy of modern study.
Like Thomas Edison after him, Meucci was a master of practical chemistry. Numerous of his processes remain unused to this day. He developed strange chemical coatings; using saltwater, graphite, soapstone, wax, muriatic acid, asbestos, sulfur, and various bonding resins to treat wire conductors. Wire lines, specially treated by Meucci, had current rectifying abilities. These absorbed and directed both terrestrial and aerial electricity into the line, a one-way charge valve. Technically what he created is a large surface area diode.
When these specially coated wires were elevated, Meucci enhanced the absorption of “atmospheric electricity” into his system. Prevented from escape by chemical coatings, a steady stream of aerial charges were absorbed into the wire line. He succeeded in powerfully operating his system with “aerial electricity” alone.
Meucci now freely used aerial and earth electricity to power his teletrofonic system. In addition, he discovered that the latent power in strong permanent magnets could amplify speech with very great power. When coupled with energy derived from the ground, Meucci found that true amplifications could be effected. Meucci found that vocal force being sufficiently powerful to produced amplified reproductions at great distances in certain of his models which utilized magnetite “flour”.
Sound-responsive soft iron cores were replaced with lodestone and surrounded by various powdered core composites developed in Meucci’s laboratory. Lodestones, surrounded with cores of flour-fine iron powders, produced enormous outputs. Meucci used exceedingly fine copper windings. The vocal range of these magnetic responders was considerable when made in Meucci’s own unique design.
Clear, velvety speech was communicated with great power in these fine-powder core designs. His use of flour-fine magnetite powders produced the world’s first ferrites; composites of iron, zinc, and manganese later used in radiowave transformers.
His teletrofoni were now fully formed, handheld devices of some weight. Surviving models from his system resemble those much later manufactured by Bell telephone. They are cup-shaped, wooden casings…handheld transmitter-receivers. One speaks into the device, and then listens from the same for replies. Meucci’s diagrams, notebooks, and models prove his priority over all the historically successive telephone designs.
In addition, Meucci used diaphragms which conducted the current which vocalizations could modulate. He developed remarkable graphite-salt coatings to enhance the electrical conductivity of his responder diaphragms, preceding Edison’s carbon button microphone by a full 24 years!
TRANSOCEANIC
In addition to his existing system, Meucci conceived of entirely new directions in communication arts. His mind turned toward the sea…and to transoceanic teletrofonic communication. Meucci tested the idea that seawater could actually replace telegraph cables, bizarre as it must yet sound. His notion would be termed “subaqueous conduction wireless”. Others had achieved moderate results across limited waterways. Sommering, Lindsay, and Morse each sent weak telegraph signals across streams. Meucci envisioned the whole Atlantic as a possible reservoir for the transmission of telephonic signals.
His experiments took him down to the Staten Island seashore with his teletrofono, batteries, and large plates of both copper and zinc. The dissimilar metal plates were submerged quite a distance from each other. Vocal messages spoken into the sea were electrically retrieved by a teletrofonic apparatus connected to an equivalent arrangement of widely separated, water-immersed plates on an opposed part of the distant shore. The signals were clearly heard.
Most engineers will object that these experiments could not sustain vocal communications across great distances. They will say this because transmitter power should be so dispersed that no intelligible signal could ever be retrieved. The experiment having been tried across short distances actually works. The most amazing rediscovery concerns the signal-regenerative ability of seawater. Seawater requires only an infinitesimal transmitter current in order to achieve strong signal exchanges.