The Evolution of the Telephone


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This is a presentation I researched and put together for a job interview.

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  • Alexander Graham Bell, a Scottish-born speech teacher from Boston, was working on an experimental telegraph one day when it began to function strangely because of a loose part. This accident gave Bell insight into how voices could be reproduced at a distance. He went on to build a simple transmitter and receiver, and as he and his assistant Thomas Watson were getting ready to test it, Bell spilled some acid on himself. In another room, Watson could hear him calling for him through the receiver. The first telephone call was thus made, and Bell was awarded a patent for the electric telephone in March of 1876. This, of course, did not come without controversy from other inventors who were also doing pioneering work on the early telephone. Bell’s claim to being the inventor of the first telephone had to be defended in court some 600 times! While others did make significant contributions, it was Bell who was the first to recognize its commercial viability.
  • Before automatic exchanges were invented, all calls were placed through manual exchanges in which a small light on a switchboard alerted an operator that a caller wanted service. The operator inserted an insulated electrical cable into a jack corresponding to the caller requesting service. This allowed the operator and the caller to converse. The caller told the operator the called party’s name, and the operator used another cord adjacent to the first to plug into the called party’s jack and then operated a key that connected ringing current to the called party’s telephone. The operator listened for the called party to answer, and then disconnected to ensure the privacy of the call. The first switchboard went into commercial service in 1878 with 21 subscribers in New Haven Connecticut, and not long after they began to sprout up across the country.
  • (read slide first) Almon Stowger in 1889 invented the automatic switch to connect two parties without the aid of an operator. An undertaker in Kansas City, Stowger suspected that local operators were routing the calls to his rivals, so he wanted to cut the women out of the calling process.
  • The telephone sends electric signals whose current responds to the air pressure of the original sound -- in this case, the human voice. Once the voice passes into the microphone, it changes into variable electric current. This modulated current travels through copper wires to the receiver. There, it drives an electromagnet which makes a diaphragm vibrate, reproducing the original sounds. So, the telephone basically improved upon the telegraph by adding a speaker, microphone, and amplifier. Antisidetone network is a small assembly of electrical parts that keeps the caller’s voice from sounding too loud.
  • Long distance telephone calls were made feasible through the use of signal boosters to amplify fading signals as they traveled through the copper wires. Long distance telephone service began in 1881 between Boston and Salem and the system grew fairly slowly after that. Interesting fact: In 1927, a three minute call from New York to London cost $75, took at least eight operators and fourteen minutes to establish the connection. In 1945, the same call would cost $12 and take only 90 seconds to connect, due to improvements in technology. This trend has been ongoing and now long distance calls cost a tiny fraction of what they once did.
  • At first, telephones had no dial pad, electronic switches, or ringer. The caller would crank a handle on the phone to call the local switchboard operator who would connect the caller to the other party. Before bells were installed as ringers, people would have to either tap, whistle, or shout through the phone to get the attention of the person they were calling.
  • In the 1890s a new smaller style of telephone was introduced, packaged in three parts. The microphone stood on a stand, known as a "candlestick" for its shape. The receiver hung on a hook with a switch in it, known as a "switchhook." Previous telephones required the user to operate a separate switch to connect either the voice or the bell. With the new kind, the user was less likely to leave the phone "off the hook".
  • Cradle designs were also used at this time, having a handle with the receiver and microphone attached, separate from the cradle base that housed the magneto crank and other parts. They were larger than the "candlestick“ models and more popular.
  • The rotary dial -- which routes a call using a set of switches activated by a series of pulse signals -- was developed in 1900 but was not installed on a large scale until 1914 in Newark, New Jersey.
  • Bell’s Model 102 turned out to be the most popular and longest lasting physical style of the telephone. A carbon granule microphone (which made calls much clearer) and electromagnetic speaker were used in a single molded plastic handle, which sat in a cradle in the base unit when not in use. After the 1930s, the base also enclosed the bell and induction coil, obviating the old separate ringer box. Power was supplied to each subscriber line by central office batteries instead of a local battery. For the next half century, the network behind the telephone became progressively larger and much more efficient, but after the rotary dial was added the telephone itself changed little until the 1960s.
  • Dual tone multi-frequency phones, or touchtone phones, as they were more commonly known, entered the scene in the early 1960’s and forever changed the way people made phone calls.
  • Cordless phones used short range radio signals transmitted from a base unit to a handset with a range of around 100ft, allowing people for the first time to do two things at once. I have to wonder if this might have triggered the rise in ADD cases in America.
  • Mobile phones appeared in the early 1980's. They started out being marketed as car phones, mainly because they were too big too fit in anyone’s pocket. 1 million cell phones were in service by 1987 and quickly jumped to 9 million in 1992 and today there are over 4.1 BILLION used worldwide. Cell phones use a network of specialized base stations known as cell sites Computers control the amount of the radio spectrum needed to serve the customers. Available frequencies are allocated to ensure that all calls can be handled when a phone is activated.
  • And of course with the invention of the mobile phone came the ability to take your phone to the streets or even call somebody while in the middle of skiing in the mountains.
  • Thankfully, mobile phones did get smaller and cheaper, giving them mass appeal and marketability. We’ve all probably had this style of phone at one time or another.
  • Then came the popular flip or clamshell design of cell phones. This one is Motorola’s popular Razor phone.
  • And then came the phones with sliding keyboards, making it all the more easy to text or write emails, especially for those who (like me) can’t do the predictive texting on regular phones.
  • Then came the Smart Phone, which allowed phones to function as miniature computers complete with hi-speed internet connections and email.
  • And the ubiquitous Blackberry, which has become more like another appendage for millions of business people worldwide.
  • And then bluetooth technology came on the scene and revolutionized the way we make calls again. Using short-range radio signals, people could now talk through their cellular phones completely hands and wire-free.
  • Touchscreen phones revolutionized phones again around 2006, giving phones a whole new level of functionality with the ability to respond to touches via an LCD screen.
  • The most famous touch screen phone, of course, being Apple’s iPhone. Time Magazine named the iPhone the Invention of the Year in 2007, and has since then become recognized as the standard for technological innovation.
  • The latest revolution in phones is VoIP, which stands for Voice over Internet Protocol, which is basically making phone calls through the internet. The technology uses a broadband Internet connection to send calls that are received by someone using an analog phone line. Special adapter boxes also allow calls over the Internet from a regular analog telephone. Long distance and international calls can be made at much lower cost depending on the service. Some services like Skype, even offer free long distance calls. The only downside to VoIP telephones are that they will not work in the event of a power outage, and emergency services cannot trace your address with them like they can with a landline.
  • Well, as you can see, we’ve come a long way in 125 years. Wheras the first telephones could barely connect you to someone living in the same town, phones can now connect you instantly to virtually anyone in the world—and not only can they make calls, but now effectively function as miniature pagers, answering machines, tv’s, cameras, video game systems, music players, GPS’s and computers. Today, the world is literally at your fingertips.
  • We’ve gone from big and bulky to slim and subtle.
  • Or in other words, we’ve gone from looking ridiculous for talking on a phone the size of a 2x4 to appearing like you’re crazy for looking like you’re talking to yourself. Whether that’s really progress, I don’t know.
  • And as far as the future goes, only time will tell what phones will look like and what they’ll be able to do.
  • The Evolution of the Telephone

    1. 1. The Evolution of the Telephone: From the Crank Phone to the iPhoneJuly 20, 2009 Created by Mark Litwa
    2. 2. How It All Began• An accident gives Alexander Graham Bell his idea for the telephone• Alexander Graham Bell patents the electric telephone in 1876• Lawsuits were filed by various individuals, and Bell’s claim to being the inventor of the first telephone had to be defended in court some 600 times
    3. 3. Switchboard Operators
    4. 4. Switchboard Operators• The first telephone operators were under-trained, unsupervised telegraph boys but were soon replaced by young women who proved to be more pleasant and reliable• The ever increasing number of callers soon transformed the profession. By 1946, nearly a quarter-million switchboard operators were employed by AT&T• In 1921, Omaha, Nebraska opened the first all- automatic exchange• Today there are no telephones served by manual exchanges in the United States. All telephone subscribers are served by automatic exchanges run by computers, which perform the functions of the human operator
    5. 5. How They Work• Sound waves are converted into electrical signals, and electrical signals into sound waves• The telephone required the simultaneous invention of the microphone, signal amplifiers and speaker• Parts: – Transmitter (microphone) – Receiver (speaker) – Dial (pulse or tone) – Alerter/Ringer – Antisidetone network
    6. 6. Long Distance1881 Boston-Salem1884 New York-Boston1892 New York-Chicago1893 Boston-Chicago1895 Chicago-Nashville1896 Kansas City-Omaha1897 New York-Charleston1898 New York-Kansas City1927 Columbia, MO-London
    7. 7. Hand Cranked Wall-1880’s
    8. 8. Candlestick-1890’s
    9. 9. Cradle Phone-1890’s
    10. 10. Candlestick Rotary-1914
    11. 11. Desktop Rotary-1920’s
    12. 12. Touchtone-1960’s
    13. 13. Wall Touchtone-1970’s
    14. 14. Cordless-1980’s
    15. 15. Mobile/Cellular-1983
    16. 16. Candy Bar-1990’s
    17. 17. Clamshell/Flip
    18. 18. Sliding/Qwerty Keyboard
    19. 19. Smart Phone
    20. 20. Blackberry
    21. 21. Bluetooth
    22. 22. Touch Screen
    23. 23. iPhone
    24. 24. VoIP (eg, Skype, Vonage)
    25. 25. Then and Now
    26. 26. Then NowMake calls Make calls Text Voicemail Pictures Video Music Internet Email GPS Videogames And more!
    27. 27. From Big & Bulky to Slim & Subtle
    28. 28. The Future?
    29. 29. ReferencesKrupa, Frederique (1992). The Evolution of the Telephone System: From Bells Electric Toy to the Internet. Retrieved July 15, 2009, from /frede/telephone.html“Telephone.” Wikipedia (2009). Retrieved July 16, 2009, from“Telephone.” Microsoft Encarta Online Encyclopedia (2009). Retrieved July 16, 2009, from