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Private Line's Telephone History
Parts 1, 2 & 3 "We picture inventors as heroes with the genius to recognize and solve a society's problems. In reality, the greatest inventors have been tinkerers who loved tinkering for its own sake and who then had to figure out what, if anything, their devices might be good for." Jared Diamond I. Introduction I. Introduction"...an inspired black-haired Scotsman of twenty eight, on the eve of marriage, vibrant and alive to new ideas." Alexander Graham Bell: The Life and Times of the Man Who Invented the Telephone On March 10, 1876, in Boston, Massachusetts, Alexander Graham Bell invented the telephone. Thomas Watson fashioned the device itself; a crude thing made of a wooden stand, a funnel, a cup of acid, and some copper wire. But these simple parts and the equally simple first telephone call -- "Mr. Watson, come here, I want you!" -- belie a complicated past. Bell filed his application just hours before his competitor, Elisha Gray, filed notice to soon patent a telephone himself. What's more, though neither man had actually built a working telephone, Bell made his telephone operate three weeks later using ideas outlined in Gray's Notice of Invention, methods Bell did not propose in his own patent. Intrigue aside for now, the story of the telephone is the story of invention itself. Bell developed new and original ideas but did so by building on older ideas and developments. Bell succeeded specifically because he understood acoustics, the study of sound, and something about electricity. Other inventors knew electricity well but little of acoustics. The telephone is a shared accomplishment among many pioneers, therefore, although the credit and rewards were not shared equally. That, too, is often the story of invention. Telephone comes from the Greek word tele, meaning from afar, and phone, meaning voice or voiced sound. Generally, a telephone is any device which conveys sound over a distance. A string telephone, a megaphone, or a speaking tube might be considered telephonic instruments but for our purposes they are not telephones. These transmit sound mechanically and not electrically. How's that? Speech is sound in motion. Talking produces acoustic pressure. Speaking into the can of a string telephone, for example, makes the line vibrate, causing sound waves to travel from one end of the stretched line to the other. A telephone by comparison, reproduces sound by electrical means. What the Victorians called "talking by lightning." A standard dictionary defines the telephone as "an apparatus for reproducing sound, especially that of the voice, at a great distance, by means of electricity; consisting of transmitting and receiving instruments connected by a line or wire which conveys the electric current." Electricity operates the telephone and it carries your voice. With that important point established, let's look at telephone history. Modern telephones use electret microphones for transmitters and piezoelectric transducers for receivers but the principle described is the same. Sound waves picked up by an electret microphone causes "a thin, metal-coated plastic diaphragm to vibrate, producing variations in an electric field across a tiny air gap between the diaphragm and an electrode."[B] A piezoelectric transducer uses material, which converts the mechanical stress of a sound wave upon it into a varying electrical signal. Telephone history begins, perhaps, at the start of human history. Man has always wanted to communicate from afar. People have used smoke signals, mirrors, jungle drums, carrier pigeons and semaphores to get a message from one point to another. But a phone was something new. Some say Francis Bacon predicted the telephone in 1627; however, his book New Utopia only described a long speaking tube. A real telephone could not be invented until the electrical age began. And even then it didn't seem desirable. The electrical principles needed to build a telephone were known in 1831 but it wasn't until 1854 that Bourseul suggested transmitting speech electrically. And it wasn't until 22 years later in 1876 that the idea became a reality. While Da Vinci predicted flight and Jules Verne envisioned space travel, people did not lie awake through the centuries dreaming of making a call. Who in the fifteenth century could have imagined a pay phone on the street corner or a fax machine on their desk? Telephone development did not proceed in an organized line like powered flight, with one inventor after another working to realize a common goal, rather, it was a series of often disconnected events, mostly electrical, some accidental, that made the telephone possible. I'll cover just a few. II. Early Telephone DevelopmentIn 1729 English chemist Stephen Gray transmitted electricity over a wire. He sent charges nearly 300 feet over brass wire and moistened thread. An electrostatic generator powered his experiments, one charge at a time. A few years later, Dutchman Pieter van Musschenbroek and German Ewald Georg von Kleist in 1746 independently developed the Leyden jar, a sort of battery or condenser for storing static electricity. Named for its Holland city of invention, the jar was a glass bottle lined inside and out with tin or lead. The glass sandwiched between the metal sheets stored electricity; a strong charge could be kept for a few days and transported. Over the years these jars were used in countless experiments, lectures, and demonstrations. In 1753 an anonymous writer, possibly physician Charles Morrison, suggested in The Scot's Magazine that electricity might transmit messages. He thought up a scheme using separate wires to represent each letter. An electrostatic generator, he posited, could electrify each line in turn, attracting a bit of paper by static charge on the other end. By noting which paper letters were attracted one might spell out a message. Needing wires by the dozen, signals got transmitted a mile or two. People labored with telegraphs like this for many decades. Experiments continued slowly until 1800. Many inventors worked alone, misunderstood earlier discoveries, or spent time producing results already achieved. Poor equipment didn't help either. Balky electrostatic generators produced static electricity by friction, often by spinning leather against glass. And while static electricity could make hair stand on end or throw sparks, it couldn't provide the energy to do truly useful things. Inventors and industry needed a reliable and continuous current. In 1800 Alessandro Volta produced the first battery. A major development, Volta's battery provided sustained low powered electric current at high cost. Chemically based, as all batteries are, the battery improved quickly and became the electrical source for further experimenting. But while batteries got more reliable, they still couldn't produce the power needed to work machinery, light cities, or provide heat. And although batteries would work telegraph and telephone systems, and still do, transmitting speech required understanding two related elements, namely, electricity and magnetism. In 1820 Danish physicist Christian Oersted demonstrated electromagnetism, the critical idea needed to develop electrical power and to communicate. In a famous experiment at his University of Copenhagen classroom, Oersted pushed a compass under a live electric wire. This caused its needle to turn from pointing north, as if acted on by a larger magnet. Oersted discovered that an electric current creates a magnetic field. But could a magnetic field create electricity? If so, a new source of power beckoned. And the principle of electromagnetism, if fully understood and applied, promised a new era of communication. In 1821 Michael Faraday reversed Oersted's experiment. He got a weak current to flow in a wire revolving around a permanent magnet. In other words, a magnetic field caused or induced an electric current to flow in a nearby wire. In so doing, Faraday had built the world's first electric generator. Mechanical energy could now be converted to electrical energy. Is that clear? This is a very important point. The simple act of moving ones' hand caused current to move, mechanical energy into electrical energy. Although many years away, a dynamo powered turbine would let the power of flowing water or burning coal produce electricity. Got a river or a dam? The water spins the turbines, which turns the generators, which produce electricity. The more water you have the more generators you can add and the more electricity you can produce, mechanical energy into electrical energy. (By comparison, a motor turns electrical energy into mechanical energy. Thanks to A. Almoian for pointing out this key difference.) Faraday worked through different electrical problems in the next ten years, eventually publishing his results on induction in 1831. By that year many people were producing electrical dynamos. But electromagnetism still needed understanding. Someone had to show how to use it for communicating. In 1830 the great American scientist Professor Joseph Henry transmitted the first practical electrical signal. A short time before Henry had invented the first efficient electromagnet. He also concluded similar thoughts about induction before Faraday but he didn't publish them first. Henry's place in electrical history however, has always been secure, in particular for showing that electromagnetism could do more than create current or pick up heavy weights -- it could communicate. In a stunning demonstration in his Albany Academy classroom, Henry created the forerunner of the telegraph. In the demonstration, Henry first built an electromagnet by winding an iron bar with several feet of wire. A pivot mounted steel bar sat next to the magnet. A bell, in turn, stood next to the bar. From the electromagnet Henry strung a mile of wire around the inside of the classroom. He completed the circuit by connecting the ends of the wires at a battery. Guess what happened? The steel bar swung toward the magnet, of course, striking the bell at the same time. Breaking the connection released the bar and it was free to strike again. And while Henry did not pursue electrical signaling, he did help someone who did. And that man was Samuel Finley Breese Morse. From the December, 1963 American Heritage magazine, "a sketch of Henry's primitive telegraph, a dozen years before Morse, reveals the essential components: an electromagnet activated by a distant battery, and a pivoted iron bar that moves to ring a bell." In 1837 Samuel Morse invented the first workable telegraph, applied for its patent in 1838, and was finally granted it in 1848. Joseph Henry helped Morse build a telegraph relay or repeater that allowed long distance operation. The telegraph later helped unite the country and eventually the world. Not a professional inventor, Morse was nevertheless captivated by electrical experiments. In 1832 he heard of Faraday's recently published work on inductance, and was given an electromagnet at the same time to ponder over. An idea came to him and Morse quickly worked out details for his telegraph. As depicted below, his system used a key (a switch) to make or break the electrical circuit, a battery to produce power, a single line joining one telegraph station to another and an electromagnetic receiver or sounder that upon being turned on and off, produced a clicking noise. He completed the package by devising the Morse code system of dots and dashes. A quick key tap broke the circuit momentarily, transmitting a short pulse to a distant sounder, interpreted by an operator as a dot. A lengthier break produced a dash. Telegraphy became big business as it replaced messengers, the Pony Express, clipper ships and every other slow paced means of communicating. The fact that service was limited to Western Union offices or large firms seemed hardly a problem. After all, communicating over long distances instantly was otherwise impossible. Yet as the telegraph was perfected, man's thoughts turned to speech over a wire. In 1854 Charles Bourseul wrote about transmitting speech electrically in a well-circulated article. In that important paper, the Belgian-born French inventor and engineer described a flexible disk that would make and break an electrical connection to reproduce sound. Bourseul never built an instrument or pursued his ideas further. In 1861 Johann Phillip Reis completed the first non-working telephone. Tantalizingly close to reproducing speech, Reis's instrument conveyed certain sounds, poorly, but no more than that. A German physicist and schoolteacher, Reis's ingenuity was unquestioned. His transmitter and receiver used a cork, a knitting needle, a sausage skin, and a piece of platinum to transmit bits of music and certain other sounds. But intelligible speech could not be reproduced. The problem was simple, minute, and at the same time monumental. His telephone relied on its transmitter's diaphragm making and breaking contact with the electrical circuit, just as Bourseul suggested, and just as the telegraph worked. This approach, however, was completely wrong. Reproducing speech practically relies on the transmitter making continuous contact with the electrical circuit. A transmitter varies the electrical current depending on how much acoustic pressure it gets. It must be in continuous contact, even though people pause and stop while talking. Turning the current off and on could not begin to duplicate speech since speech, once flowing, is itself a fluctuating wave of continuous character. Reis's instrument, in fact, worked only when sounds were so soft that the contact connecting the transmitter to the circuit remained unbroken. Speech may have traveled first over a Reis telephone however, it would have been done accidentally and against every principle he thought would make it work. And although accidental discovery is the stuff of invention, Reis did not realize his mistake, did not develop his instrument further, nor ever claim to have invented the telephone. The definitive book in English on Reis is: Thompson, Silvanus P. Phillip Reis: Inventor of The Telephone. E.&F.N. Spon. London. 1883 In the early 1870s the world still did not have a working telephone. Inventors focused on telegraph improvements since these had a waiting market. A good, patentable idea might make an inventor millions. Developing a telephone, on the other hand, had no immediate market, if one at all. Elisha Gray, Alexander Graham Bell, as well as many others, were instead trying to develop a multiplexing telegraph a device to send several messages over one wire at once. Such an instrument would greatly increase traffic without the telegraph company having to build more lines. As it turned out, for both men, the desire to invent one thing turned into a race to invent something altogether different. And that is truly the story of invention. lll. "Major Telephone Breakthrough"
Bell was nearly beaten to the patent office by Elisha Gray, who had independently developed a very similar invention. Gray arrived just hours after Bell at the Patent Office, filing a "caveat," a confidential report of an invention that was not yet perfected. Western Electric, cofounded by Gray, became one of the Bell System's major competitors. Western Union was another major competitor, already having established itself as a communications provider with the telegraph system. Another famous inventor, Thomas Edison, took advantage of Bell's failure to secure a patent in Britain for the Bell receiver, and received a patent for a new receiver, the "electro-motograph," which required continuous cranking -- else the conversation would end. However, by 1880, the Bell transmitter and the Edison receiver were combined and used throughout Britain. The first permanent outdoor telephone wire, strung in 1877, covered a distance of three miles. Bell could be credited with the anticipation of fiber optics - he worked on a "photophone," which could actually transmit sound for a short distance over a beam of light. Commercial telephone service began in the United States in 1877. The workable exchange, developed in 1878, enabled calls to be switched among any number of subscribers rather than requiring direct lines. Exchanges were handled manually, first by boys, then by the now- famous women operators in their bustles. In 1879, telephone subscribers began to be designated by numbers rather than names -- as a result of an epidemic of measles. A Lowell, Massachusetts doctor, concerned about the inability of replacement exchange operators to put calls through because they would not be familiar with the names associated with all the jacks on the switchboards, suggested the alpha-numeric system of identifying customers by a two- letter and five-digit system. The dial phone was invented in the 1880s by Almond Brown Stroger, who was a Kansas City, MO undertaker and was convinced that the Bell Telephone operator was sending calls for his funeral home to the operator's brother-in-law... Stroger invented the dial telephone and installed automatic exchanges in the US and Europe. In 1924, the Bell Telephone System decided that using operators was NOT the way to go, and they licensed Stroger's technology. The step by step switch used to receive the dial pulses is/was called a Stroger Switch, after its inventor. Because of the largely monopolistic power of the American Bell Company, profits were held high, reaching levels of $1 million in revenue while paying out $600,000 in dividends in 1882. Competition remained a major threat, as the Bell, Western Union, and Western Electric systems were incompatible and not connected. As many as three or more independent telephone companies battled in a given area for customers. Problems with the telephone occurred when other applications of electricity flourished, particularly trolley cars and street lamps. Natural electricity also interfered with the system, as lightning wreaked havoc on the lines. Long-distance service was established and grew in the 1880s using metallic circuits. The common-battery system, developed by Hammond V. Hayes in 1888, permitted a central battery to supply all telephones on an exchange with power, rather than relying upon each unit's own troublesome battery. The first automatic dialing system was patented in 1891 by a Kansas City undertaker who believed that crooked operators were sending his business elsewhere -- with his main objective being to eliminate the operators. The first coin telephone was installed in Hartford, Connecticut in 1900. Party lines were soon developed to lower the cost of the telephone for individual families, especially those in rural locations. A young inventor, Dr. Lee De Forest, began work in 1906 on applying what was known as an "audion," a three-element vacuum tube, which could amplify radio waves. He recognized the potential for installing audions or repeaters on telephone lines to amplify the sound waves at mid-points along the wires. The Bell System bought the rights to De Forest's patents in 1913. Long-distance telephone service was constructed on the New York to San Francisco circuit using loading coils and repeaters. American Telephone and Telegraph (AT&T) took control of Western Union telegraph Company in a "hostile takeover," in 1911, having purchased the Western Union stocks through a subsidiary. The two eventually merged, sharing financial data and telephone lines. In 1918, ten million Bell System telephones were in service. Theodore Vail, president of the Bell System from 1885 to 1887 and 1907 to 1919, faced the challenge of making a large private corporation adopt a policy of subordinating the maximization of profit to the provision of service to its customers (Brooke, 1976). The political and business environment in the United States following the First World War was strongly "anti-monopolistic." Yet, advantages to single- company service or limiting service in a given area to few competitors had its advantages. Under Vail's leadership, automatic switching of large numbers of calls was made possible in 1921, using "phantom circuits," which allowed three telephone conversations to be conducted on two pairs of wires. The "French" phone, with the transmitter and receiver in a single handset, was developed by the Bell System around 1904, but was not released on a widespread basis because it cost more than the desk sets. They ultimately became available to subscribers in 1927. The first transatlantic service, from New York to London, became operational in 1927, and was transmitted by radio waves. Research in electronic telephone exchanges began in 1936 in Bell Labs, and was ultimately perfected in the 1960s with its Electronic Switching System (ESS). Bell benefited greatly from US defense spending during World War II in its laboratories. War-time experiments, innovations, and inventions brought Bell to the forefront of telecommunications in the post-war era. The first commercial mobile telephone service was put in service in 1946, linking moving vehicles to telephone networks by radio. The same year brought transmission via coaxial cables, resulting in a major improvement in service as they were less likely to be interrupted by other electrical interference. Microwave radio transmission was used for long-distance telephony in 1947. The transistor, a key to modern electronics, was invented at Bell Labs in 1947. A team consisting of William Schockley, Walter Brattain, and John Bardeen demonstrated the "transistor effect," using a germanium crystal that they had set up in contact with two wires two-thousandths of an inch apart. Changes were underway in the 1950s. Consumers initially objected to all-numeral telephone numbers (All Number Calling, or ANC) that were introduced in the latter half of the decade. Consumer demand for telephones had outstripped the ability of the telephone system to supply all of the required numbers, which were restricted by the alpha-numeric combinations in place for decades. The laying of transatlantic telephone cables began in 1955. Care was taken to ensure that the submarine repeaters would be of the highest quality, guaranteed to last at least twenty years before replacement would be required. Telstar, the world's first international communications satellite, was rocketed into orbit on July 10, 1962, with a collaboration between NASA and the Bell System. Satellites in geosynchronous orbit are used mostly for long-distance service. Videophones, developed in the mid-1960s, were becoming more affordable and practical with the combination of devices that eased the transmission and reception of both audio and video signals over telephone lines. Fiber optic cables (or "fiber optics"), developed in the early 1980s, offered the potential to carry greater volumes of calls than satellite or microwave links. Electrical telephone signals are fed into tiny semiconductor lasers, which produce pulses of light in response to incoming signals and are bounced down the inside of extremely thin glass fibers. Today's cellular mobile telephones rely upon a series of "cells," each with its own central radio transmitter and receiver. Each cellular telephone unit also has its own central transmitter-receiver, permitting it to receive seamless transmission as they enter and exit from a cell. The impact of the telephone has been described as both positive and negative. On the negative side, wars are waged more easily, the scope of human conflict has been extended along telephone lines, the multi-generational household has been broken-up as living alone is no longer an experiment in isolation, and the time-space continuum seems to be compressed faster than previously thought possible (Brooks, 1976). On the other hand, the invention of the telephone has resulted in the rapid and diffuse dissemination of technical and scientific information, saved lives through links to emergency services, made possible the modern city through telephonic connections, increased the speed and ease with which information changes place, and accelerated the rate of scientific and technological change and growth in industry (Brooks, 1976). It is curious in contrast to now consider the musings of Herbert Casson (1910, p. 299), who ended his book with a question, "Who could have foreseen what the telephone bells have done to ring out the old ways and to ring in the new; to ring out delay and isolation and to ring in the efficiency and friendliness of a truly united people?" The future combination of various means of telecommunications, with the personal computer and recent inventions such as the facsimile machine, could never have been foreseen yet they hold the potential for vast changes in the global environment for society, business and industry, and governments. References American Telephone and Telegraph (AT&T). (1979).
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