Introduction to Electrical Telegraphy#

Alright, let’s dive into the fascinating world of electrical telegraphy. Imagine a time when the fastest way to send a message across land was by carrying it physically or using visual signals like flags or smoke. Electrical telegraphy changed all that, kicking off what we now call telecommunications. It’s a really important part of history, especially for us in electrical engineering, because it was essentially the very first electrical telecommunications system and arguably the first big win for electrical engineering as a field.

At its heart, electrical telegraphy is about sending messages point-to-point over long distances using electrical signals carried by wires. People used this system quite heavily from the 1840s right up until the late 20th century.

Think of it like this: You have two places far apart, let’s call them “telegraph offices.” These offices are linked by wires, usually strung up high on poles, kind of like the power lines you see today. When you wanted to send a message, an operator at one office would use electrical signals to make something happen at the other end, which another operator would then translate back into a message.

Over time, folks came up with many different ways to make this work using electricity. But the really successful ones generally fell into two main categories:

1. Needle Telegraphs: These systems used electric current to create magnetism, which would then move a needle. This needle would point to letters or symbols printed on a board. Earlier versions needed lots of wires, one for each needle or pair of needles. The Cooke and Wheatstone system, which came out in 1837, was the most popular needle telegraph and the first to be used commercially.
2. Armature Systems: These systems used the electric current to activate an electromagnet, which would pull on a piece of metal called an armature. This armature hitting something would make a clicking sound. Messages were sent by making these clicks in specific rhythmic patterns, like a code. The most famous example is the Morse system and its code, invented by Samuel Morse in 1838. Morse code, particularly a modified version, became the international standard by 1865.

Electrical telegraphs weren’t just for sending personal messages (called telegrams, which you paid for). They were crucial for industries too, especially the growing railway companies. Railways used them to signal between stations, helping to control train movements and prevent collisions. This was often done with systems using bells and those three-position needle telegraphs.

The electrical telegraph quickly took over from older visual systems like semaphores because it wasn’t limited by weather or visibility. By the second half of the 1800s, many countries had big networks covering their cities and towns, allowing people to send messages across the country relatively quickly.

A huge step happened starting in 1850: laying submarine cables. This allowed messages to travel between continents rapidly for the very first time, connecting the world in a way never before possible. The instant, or near-instant, global communication the telegraph enabled had a massive impact on society and the economy. It also paved the way for other technologies, like Guglielmo Marconi’s wireless telegraphy (radio communication), which started in the 1890s.

Eventually, manual telegraph operation started to be replaced by automated systems like teleprinters and networks like Telex. Then, telephones became more common, pushing telegraphy into more specialized uses. Finally, with the rise of the internet and email in the 1990s, dedicated telegraph networks became largely obsolete.

How it Started: Before the Wire#

Before the magic of electricity, people weren’t just sitting around doing nothing to send messages over distance. They used all sorts of clever methods. These were mainly visual systems, like:

• Beacons and Smoke Signals: Simple, very old methods for transmitting basic information (like “danger!”).
• Flag Semaphore: Using flags held in different positions to represent letters or codes.
• Optical Telegraphs: More complex systems, like the Chappe system in France, using mechanical arms on towers to signal messages visually from one station to the next.

There were also auditory methods, like the “talking drums” used in some West African cultures to send messages mimicking tonal languages over a few miles.

Robert Hooke, a British scientist, thought up a visual telegraph system back in 1684, even detailing how it might work, driven by military needs. The Chappe optical telegraph in France, starting in the late 1700s, was a major example, building a network covering thousands of kilometers with hundreds of stations. These optical systems were the best available for rapid long-distance communication before electricity came along.

The Early Electrical Experiments#

Once people started playing around with electricity, they quickly noticed how fast its effects seemed to travel. This got a lot of inventors thinking: could we use this speed to send messages far away? They tried out everything they knew about electricity at the time: sparks, static attraction, chemical changes caused by current, electric shocks, and eventually, the big one for telegraphy, electromagnetism.

One of the earliest electrical ideas came in 1753 from someone writing in a Scottish magazine. They suggested an electrostatic telegraph.

Electrostatic Telegraph: An early concept using static electricity. By connecting wires (one for each letter) to an electrostatic machine, a charge would be sent down the wire. At the other end, the charge would cause something light, like a pith ball, to move, indicating the letter.

This idea, while interesting, was impractical because electrostatic machines and their signals were limited and hard to control over distance.

Georges-Louis Le Sage in 1774 actually built a very early electric telegraph, but it was super basic – only worked within two rooms of his house and needed a whopping 26 wires, one for each letter!

Things got more practical after Alessandro Volta invented the voltaic pile in 1800.

Voltaic Pile: An early form of electric battery that provided a steady, continuous electric current. Before this, experimenters mainly had to rely on static electricity generators or Leyden jars (early capacitors), which only gave momentary discharges.

With a continuous current, inventors could explore effects that required a steady flow of electricity.

One notable early attempt was the electrochemical telegraph.

Electrochemical Telegraph: A system where electric current causes a chemical reaction at the receiving end to display the message. Samuel Thomas von Sömmering developed one in 1809, based on an earlier idea by Francisco Salva Campillo.

Von Sömmering’s design used up to 35 wires! Each wire went into a tube filled with acid. When current was sent down a wire, it would break down the acid (electrolysis) and create bubbles next to a specific letter printed on the tube. The operator watched for the bubbles. This was a creative use of electricity, but still needed way too many wires to be practical for long distances compared to later single-wire systems.

The real game-changer for electrical telegraphy came with the discovery of electromagnetism.

Electromagnetism: The interaction between electricity and magnetism. A key principle is that an electric current creates a magnetic field.

Hans Christian Ørsted discovered this in 1820 – he noticed that an electric current could make a compass needle move. Right after that, Johann Schweigger invented the galvanometer.

Galvanometer: A device that detects and measures small electric currents using the principle of electromagnetism. It typically consists of a magnetic needle placed within a coil of wire. When current flows through the coil, it creates a magnetic field that deflects the needle. A more sensitive version was later developed by Gauss and Weber.

This was crucial! Now there was a sensitive way to detect a current sent down a wire at the other end. André-Marie Ampère quickly suggested using this for telegraphy, perhaps with small magnets under wires, but he didn’t initially realize how helpful Schweigger’s coil design would be for sensitivity. Peter Barlow tried Ampère’s basic idea in 1825 but found it only worked over very short distances (about 60 meters). William Ritchie improved on this in 1830 by putting the magnetic needles inside the wire coils, demonstrating it worked, though mainly just in a lecture hall setting.

Another vital component emerged: the electromagnet.

Electromagnet: A temporary magnet created when electric current flows through a coil of wire, usually wrapped around a core of magnetic material like iron. The magnetism is present only when the current is flowing.

William Sturgeon invented a simple electromagnet in 1825. Joseph Henry significantly improved it in 1828 by using wire with insulation and wrapping many turns around the iron core. This made a much more powerful electromagnet, strong enough to operate devices over the long, relatively high-resistance wires needed for telegraphy. Henry even demonstrated the concept by using an electromagnet to ring a bell through a mile of wire in 1831.

To make signals travel even further or operate mechanical devices, another invention was key: the electrical relay.

Electrical Relay: An electrically operated switch. A small current is used to activate an electromagnet, which then closes or opens another circuit, potentially carrying a much stronger current. In telegraphy, relays were used as signal repeaters to boost weak signals traveling over long wires, allowing messages to span greater distances.

Joseph Henry and Edward Davy independently came up with early versions of relays in 1835 and 1837. Davy’s 1837 metallic make-and-break relay was particularly practical and became essential in telegraph systems for refreshing the signal strength periodically along a long line. Davy also experimented with a printing telegraph using chemical reactions on paper tape triggered by current.

The First Working Systems Appear#

While many folks were tinkering, some managed to build actual working telegraph systems.

Francis Ronalds built one of the very first in England in 1816 using static electricity. He even buried a system in a trench and put one up overhead. His setup used revolving dials with letters. Electrical impulses sent down the wire made the dials move, indicating the message. He showed it to the British Admiralty, but they weren’t interested at the time, calling it “wholly unnecessary.” Even so, his description of the system and the challenges (like signals slowing down due to something he called “induction” – an early observation related to capacitance and inductance in wires) was the first published work on electric telegraphy, and some of his ideas were used later.

In 1832, Baron Schilling von Canstatt in Russia developed an early needle telegraph. His first version had a keyboard and used 16 keys to switch current, sending signals over eight wires to six galvanometers with needles. Different needle positions showed letters or numbers. He later improved it to use just two wires. Schilling demonstrated it over a short distance and it was even approved for a longer line, but he passed away before it was built. He also experimented with binary codes for signal transmission, a really forward-thinking idea! His work was continued by Moritz von Jacobi.

Around the same time, in 1833, two German scientists, Carl Friedrich Gauss (yes, the famous mathematician!) and Wilhelm Weber (the physicist), set up a telegraph line over buildings in Göttingen. They made a more sensitive galvanometer by combining Schweigger’s design with Gauss’s magnetic measurement tools. They also built their own commutator to switch the direction of the current. This let them move a needle at the distant end in a controlled way.

Gauss and Weber initially used their telegraph for things like coordinating clocks (sending time signals), but they soon developed a binary code and an alphabet for sending messages. This code used positive or negative voltage pulses generated by moving a coil over a magnet and switching connections with their commutator. They managed about seven letters a minute. They saw the potential but lacked funding to build a big network. However, their work influenced others. Carl August Steinheil in Munich built a telegraph network within the city in 1835-1836 and installed the first commercial system using an earth return wire instead of needing two separate wires, significantly reducing the number of wires needed.

Back in Britain by 1837, William Fothergill Cooke and Charles Wheatstone teamed up. They developed a needle telegraph system where needles on a board pointed to letters. They patented a version in May 1837 using five needles, which could code 20 letters with just six wires.

Meanwhile, independently in the United States, Samuel Morse (a painter by trade!) developed his own recording electric telegraph in 1837. His assistant, Alfred Vail, helped develop a device called the “register,” which used an electromagnet to push a stylus onto a moving paper tape, marking dots and dashes. Morse and Vail also created the famous Morse code, a system of dots (short signals) and dashes (long signals) representing letters and numbers.

The very first public message sent over Morse’s line, on May 24, 1844, was “WHAT HATH GOD WROUGHT,” from Washington D.C. to Baltimore. A truly historic moment!

Taking Telegraphy Commercial#

Once these working systems were proven, the next step was making them practical and profitable.

Making it Faster and More Efficient#

Engineers and inventors kept working to improve telegraphy, always trying to send messages faster, reduce errors, or get more messages onto the existing wires to lower costs per message.

Early efforts focused on making operation easier or faster:

• Wheatstone ABC (1840): As mentioned, this was designed for untrained users, though it was slower (up to 15 words per minute) and required someone at the other end to watch the pointer in real-time.
• Chemical Telegraphy (Alexander Bain, 1846): This system used an electrochemical reaction to mark paper. An iron pen moved across paper soaked in special chemicals. When current flowed, it caused a blue mark in the pattern of dots and dashes. It was faster than early manual methods (16.5 words per minute) and recorded the message automatically, but the chemical process had its own issues and legal battles (Bain’s patent was defeated by the Morse group in the US).

The rise of sound operators was a big step for the Morse system. Instead of reading the paper tape (which the “register” produced), operators developed the skill of understanding the Morse code directly by listening to the clicks of the sounder. This was faster and simpler, and led to the paper tape being phased out in many offices.

Automation of the printing of messages was another goal:

• Printing Telegraphs (Royal Earl House, 1846; David Edward Hughes, 1855): These machines used a keyboard at the sending end. Pressing a letter key would send a signal that caused the receiver to automatically print that letter onto paper tape. House’s system used a complex mechanical/electrical setup and later even steam power for speed (claimed 2600 words/hour). Hughes’s system used a spinning type wheel and timing, which was more stable and became widely adopted.

A significant leap in automation and efficiency came with Émile Baudot’s system (1874).

Baudot Code/System: A printing telegraph system that used a five-bit binary code for each character. Instead of timing dots and dashes manually, operators pressed keys in a rhythmic pattern representing the bits. The receiver automatically translated this five-bit code into printed characters.

The Baudot system required operators to maintain a precise rhythm, but it automated the encoding and decoding process into printed text. A five-bit code allows for 2^5 = 32 combinations. Since this isn’t enough for all letters, numbers, and punctuation, the Baudot code used “shift” characters (Letters Shift and Figures Shift), changing the meaning of the following codes until the opposite shift character was received. This concept of shifting is similar to how the Shift key on a modern keyboard works for uppercase letters and symbols. Baudot’s system typically operated around 30 words per minute.

Full automation, removing the human rhythm limitation, was achieved by Charles Wheatstone’s automatic system. Messages were pre-punched onto paper tape using a keyboard-like device called a “Stick Punch” which created holes representing Morse code. A transmitter then automatically fed this tape through, sensing the holes to send the corresponding electrical pulses at a much higher speed, up to 70 words per minute initially – very fast for the time.

Connecting the Continents: Submarine Cables#

Sending messages across land was one thing, but what about across the oceans? This was the ultimate goal for global communication. The idea of laying telegraph cables underwater came up soon after land systems were working.

The biggest technical challenge for submarine cables was insulation. The wire needed to be perfectly insulated so the electrical signal didn’t leak out into the water. A breakthrough came in the 1840s with the introduction of gutta-percha from Southeast Asia.

Gutta-percha: A natural rubber-like material, the hardened sap from the Palaquium gutta tree. It was found to be an excellent electrical insulator and resistant to seawater, making it ideal for coating the copper wires used in submarine telegraph cables.

Michael Faraday (another giant in electromagnetism!) and Charles Wheatstone quickly recognized gutta-percha’s value. In 1845, Wheatstone suggested using it for a proposed cable across the English Channel. Experiments followed, like submerging a gutta-percha coated wire off the coast of England in 1849 which worked successfully.

An English engineer, John Watkins Brett, got permission from the French government to lay the first undersea cable connecting France and England. This was done in 1850. It was a success, and soon cables were laid to Ireland and other nearby countries.

The really ambitious project was a cable across the Atlantic Ocean. The Atlantic Telegraph Company was formed in 1856 for this purpose. Laying a cable across 2,000 miles of deep ocean floor was a monumental engineering feat. Early attempts in the late 1850s faced many problems. A cable was successfully laid in 1858 but only worked intermittently for a few weeks before failing. These failures spurred a lot of study, particularly mathematical analysis of how electrical signals behave on very long underwater cables, which helped future designs.

Finally, after several mishaps, a successful transatlantic cable was completed in 1866 by the famous ship SS Great Eastern. This marked the first reliable, near-instant communication link between Europe and North America. People like John Pender were involved in these ventures and went on to form companies focused on laying cables worldwide.

The network rapidly expanded. Britain was connected to India by cable in 1870. These companies merged to form the Eastern Telegraph Company. The HMS Challenger expedition famously mapped the ocean floor in the 1870s, partly to find good routes for future cables.

Australia was linked to the global network in 1872 via a cable to Darwin, bringing news and information much faster than before. The final piece of the puzzle for a round-the-world cable network was completed in 1902 when the Pacific was crossed, connecting Australia/New Zealand to Canada.

For a long time, British companies dominated the submarine cable business. This was even a strategic goal, sometimes called the “All Red Line,” referring to the British Empire colored red on maps – the aim was to connect the empire entirely by British-owned cables for strategic communication security. By the late 19th century, British companies owned the vast majority of the world’s submarine cables.

Companies formed from these early cable ventures, like the Eastern Telegraph Company and others, eventually merged to become the Cable & Wireless Company, a major force in international telecommunications for decades.

Practical Applications Beyond Messaging#

The speed and reach of the telegraph made it useful for things beyond just sending personal or business messages.

The Beginning of the End#

Despite its revolutionary impact and long reign, the electrical telegraph eventually faded from prominence. The main reason? The rise of newer, more convenient communication technologies.

In the United States, the decline is often linked to the fate of the Western Union Telegraph Company. Western Union was the dominant telegraph company and initially a rival to the early telephone companies, like the National Bell Telephone Company (which became part of AT&T). Western Union actually had early telephone patents but made a crucial mistake by underestimating the telephone’s potential and settling a legal battle with Bell in 1878 in a way that prioritized telegraphy and limited their role in telephony. This lack of foresight about the telephone’s future proved fatal in the long run.

While the 1878 agreement itself didn’t instantly kill the telegraph, it set Western Union on a path of decline relative to the rapidly growing telephone industry. AT&T even gained control of Western Union for a few years in the early 20th century before anti-trust concerns forced them to give it up. Ultimately, AT&T acquired Western Union’s electronic mail and Telex businesses much later, in 1990.

The manual telegraph operation was first challenged by automated systems like Telex, which became important for business-to-business communication. But the increasing availability and convenience of the telephone for everyday calls gradually pushed telegraphy into niche uses. For the general public, sending telegrams mostly became something you did only for special occasions like weddings or birthdays.

The final nail in the coffin for dedicated telegraph networks was the explosive growth of the Internet and email in the 1990s. These digital technologies allowed instant text communication globally at virtually no cost per message, making the old model of paying per word or per telegram obsolete.

Today, while the concept of sending text messages electrically over wires or networks is fundamental to modern communication (like email, instant messaging, SMS), the specific dedicated electrical telegraph systems and networks discussed here, with their reliance on Morse code, sounders, teleprinters, and circuit-switched Telex, have largely disappeared. Modern “telegram” services that still exist usually just send your message over a computer network and print it out near the destination for delivery, bypassing the historical telegraph infrastructure entirely.

The era of the electrical telegraph, though ended, laid the foundation for everything that followed in electrical telecommunications and remains a foundational subject for understanding the history and principles of electrical engineering.