MCM101 Lesson 15

LESSON 15: TELEGRAPH DOES MIRACLE IN DISTANCE COMMUNICATION

1. Who successfully transmitted the first telegraph message and on what date?
   Samuel Morse successfully transmitted the first telegraph message on May 14, 1844.
2. What was the first telegraph message sent by Morse?
   The first message was “What hath God wrought”.
3. What was the term ‘telegraph’ coined by?
   The term ‘telegraph’ was coined by scientist Claude Chappe.
4. Who developed an early electric telegraph with a five-needle galvanometer in England?
   Charles Wheatstone developed an early electric telegraph with a five-needle galvanometer in England.
5. What did Samuel Morse patent in 1837?
   Samuel Morse patented his telegraph in 1837.
6. By 1862, how many kilometers of telegraph cable covered the world?
   By 1862, 240,000 km (150,000 mi) of telegraph cable covered the world.
7. Who is credited with the invention of the telephone?
   Alexander Graham Bell is credited with the invention of the telephone.
8. What were the machines that used telephone-like dialing to connect teletypes called?
   These machines were called “telex”.
9. Explain why the invention of the telegraph was a “historic day” for the print industry.
   The telegraph allowed print media to receive information from distant locations in real time, enabling them to reach larger audiences with timely news, which was not possible with the slow transport systems of the era.

1. Explain how the early telegraph system developed from visual signals to electric wires.
   It evolved from visual methods like fires, smoke signals, and drums (antiquity) to Claude Chappe’s mechanical telegraph with towers (1793), and then to experiments with electric charges through wires in the 18th and 19th centuries.
2. How did Morse’s telegraph differ from earlier systems like Wheatstone’s?
   Morse’s system used a special switch (telegraph key) to rapidly switch current, printing messages in a dot-dash code on paper ribbons, which proved more practical and superseded earlier European systems.
3. Explain the impact of the telegraph on the Associated Press.
   The telegraph allowed the Associated Press, founded in 1848, to dispatch news quickly across long distances, revolutionizing the speed and scope of news distribution.
4. How did the telephone represent an improvement over the telegraph for personal communication?
   The telephone allowed for the transmission of true sound and spoken words, enabling direct, real-time voice conversation between individuals, which was more personal and immediate than coded telegraph messages.
5. Explain the significance of Bell’s “harmonic telegraph” experiment on June 2, 1875.
   During this experiment, a stuck reed converted an intermittent current to a continuous one, allowing Bell to hear sound on his receiver, confirming that sound could be transmitted and reconverted through an electric wire.
6. How did telex automate message routing?
   Telex machines used telephone-like rotary dialing to connect teletypes and then sent baud dots code, functionally automating the routing of messages between machines.
7. Explain one major use of the telegraph during the American Civil War.
   The telegraph was used to control troop deployment and intelligence, demonstrating its military value.
8. newspaper editor in 1870 is deciding whether to invest in a telegraph connection. Based on the lesson, what is one key advantage this would provide?
   The telegraph would allow the newspaper to receive news from distant locations almost instantly, enabling them to publish more timely and comprehensive reports than competitors relying on slower mail or transport.

1. Analyze the following scenario: In 1845, a business needs to send a quick message from New York to Chicago. Based on the lesson, what communication technology would they use and why?
   They would use the telegraph, as it was the only technology at the time capable of transmitting messages over such a long distance in near real-time, unlike mail which could take days or weeks.
2. A historian argues that the telegraph was more important for business than for news. Provide evidence from the lesson to challenge this view.
   The lesson states that the Associated Press used the telegraph to dispatch news, and it was used for transmitting information about stocks and commodities. This shows it was crucial for both news and business, not one over the other.
3. Based on the lesson, how did the invention of the telephone build upon the principles of the telegraph?
   Both used electric wires to transmit signals over distance. The telephone advanced this by modulating a continuous electric current to carry the complex patterns of the human voice, rather than just simple on/off clicks for a code.
4. Apply your knowledge: Why was the transatlantic telegraph cable laid in 1866 a significant achievement?
   It connected Europe and the United States directly, allowing for nearly instantaneous communication across the Atlantic Ocean, which revolutionized diplomacy, business, and news reporting between the continents.
5. A company in the 1930s needs to send written messages frequently between Berlin and other German cities. Based on the lesson, what technology might they adopt and why?
   They might adopt the telex system, as the lesson notes the first wide-coverage telex network was implemented in Germany in the 1930s, offering reliable and inexpensive long-distance communication for written messages.
6. Why was Bell’s background in “vocal physiology and his speech instruction to the deaf” relevant to his invention of the telephone?
   This background gave him a deep understanding of sound production and transmission, which was directly applicable to the challenge of converting vocal sounds into electrical signals and back again.
7. If you were to explain the operational principle of a simple telephone to a friend, what would you say based on the lesson?
   Sound waves from your voice vibrate a diaphragm in the transmitter, changing an electric current. This current travels through a wire to the receiver, where it vibrates another diaphragm to reproduce the sound.
8. Based on the lesson, what was one key technological advancement that made the telephone more practical after its initial invention?
   The development of the magnetic telephone, which consisted of a transmitter, receiver, and a magnet, was a significant improvement and the precursor to modern phones, offering better sound transmission.