Morse Code’s Vanquished Competitor: The Dial Telegraph

In 1842, French watchmaker Louis-François Breguet invented a simpler to use but less efficient alternative

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Over the years, I’ve played with interactive telegraph exhibits in science centers and museums. I can tap out the common ••• – – – ••• of the emergency distress signal, and I know the letters H (••••) and E (•), but beyond that, Morse code’s patterns of dots and dashes run together in my brain. Stories of telegraph operators who could decipher hundreds of characters a minute still amaze me.

Recently, though, I learned about the needle telegraph. On both the sending and receiving end, the needle or needles would simply point to the desired letter. Finally, a user-friendly telegraph system, provided the user knew how to read.

The first needle telegraph was patented by William Cooke and Charles Wheatstone in Britain in 1837. The design used a set of magnetic needles arranged in a row, with letters of the alphabet arranged above and below them in a diamond grid pattern. Each needle could point left, right, or neutral; to indicate a letter, two needles would point so as to outline a path to that letter. The sending operator controlled the direction of the needles by pressing buttons that closed the circuits for the desired letter combination.

Although any number of needles could be used, Cooke and Wheatstone recommended five. This combination allowed for 20 possible characters. They omitted the letters C, J, Q, U, X, and Z. Early telegraphs were mainly used for transmitting simple signals, rather than discussion-style communication. For example, to indicate whether a one-way tunnel was clear, an operator might send the short message “wait” or “go ahead.” So the absence of a few letters wasn’t a huge shortcoming.

Operators needed minimal training to use the system, which their employers appreciated. But the system was otherwise costly to operate because it required a wire for each needle plus an additional return wire that completed the circuit. Maintaining multiple wires proved expensive, and many British railroads adopted a version that used just one needle and two wires. A single-needle system, however, required that operators learn a code to send and receive signals. Gone was the ease of simply reading letters.

Cooke and Wheatstone must have realized there was room for improvement, because in 1840 they came out with a dial (or ABC) telegraph, whose face displayed all the letters of the alphabet. The operator selected the desired letter by pressing the appropriate button and turning the handle; the needle on the receiver’s dial would swing around to point to that letter. However, a dispute between the two inventors kept this version of the telegraph from being commercialized. Only after the 1840 patent had expired did Wheatstone return to the dial telegraph, eventually patenting several improvements.

Meanwhile, the French had been using an optical telegraph system that Claude Chappe developed during the French Revolution. It relied on semaphore signals transmitted along a line of towers. By 1839, Alphonse Foy was in charge of over 1,000 optical-telegraph operators, but he saw the need to investigate the growing development of electric telegraphs. He sent Louis-François Breguet to England to study Cooke and Wheatstone’s needle telegraph. The first result was the Foy-Breguet telegraph, which used two needles that mimicked semaphore signals.

Breguet was manager of his family’s watchmaking company, Breguet & Fils, and not long after, he developed a dial telegraph that had both the appearance and the working mechanism of a clock [receiver shown at top]. When activated by an electric current from the sender, a spring connected by gears rotated the needle around the dial; an escapement—the toothed-wheel mechanism that in a clock moves the hands forward—kept the needle in place in the absence of a signal.

Breguet divided the face into 26 slots, with an inner ring of numbers and an outer ring of letters. The starting position was at the top, noted by a cross, leaving room for 25 letters. At the end of each word, the needle would return to the starting position. Some versions omitted the letter W; others omitted the letter J.

After French railroads adopted the Breguet telegraph and made it standard equipment, it became known as the French railway telegraph; it remained in use until the end of the century. Breguet’s system was also exported to Japan, connecting Tokyo and Yokohama as well as Osaka and Kobe. A new face for the telegraph incorporated Japanese katakana characters.

Of course, even Breguet’s dial telegraph was limited in the range of characters it could transmit. Operators of the needle and dial telegraphs had to somehow deal with missing letters—perhaps they just made their best guess based on context, or perhaps companies devised their own codes for specific letters or symbols. Louis-François Breguet couldn’t properly transmit the cedilla in his own name, but maybe he accepted it as a limitation of the technology.

As it happens, as early as the 1840s, Friedrich Clemens Gerke, the telegraph inspector for the Hamburg-Cuxhaven line in Germany, was noting similar shortcomings with Morse code. The code, developed by Samuel Morse and Alfred Vail in the United States, was fine for the unaccented English alphabet. To accommodate European languages, Gerke added accented letters; he also significantly revised the patterns of dots and dashes for letters and numbers, making the entire code more efficient to transmit. His version, which became known as Continental Morse Code, spread throughout Europe.

Despite the expanded code’s popularity, the International Telegraphic Union took many years to embrace it. In his 2017 book The Chinese Typewriter: A History, Thomas Mullaney describes the slow, conservative evolution of Morse code. In 1865, the ITU settled on a set of standardized symbols that were decidedly Anglocentric. Three years later, it confirmed the standard codes for the 26 letters of the English alphabet, the numerals 0 to 9, plus 16 special characters—mostly punctuation, plus the e-acute, É. In 1875, the ITU elevated É to a standard character and added six more accented letters as special characters: Á, Å, Ä, Ñ, Ö, Ü. It wasn’t until 1903 that the ITU accepted these supplemental characters as standard. Languages based on nonalphabetic characters, such as Chinese, were never incorporated, although some countries adopted their own telegraphic codes. Thus did the technology of telegraphy connect and also divide the world in new and unexpected ways.

The Breguet telegraph receiver that touched off my inquiries is on display at the Museum of the School of Telecommunication Systems Engineering at the Technical University of Madrid. The museum was started in the 1970s by a small group of professors, who scoured antique shops and flea markets to collect artifacts representing the history of communications. Rather than confining its objects to a dedicated space, the museum maintains exhibit cases in hallways throughout the school, where students, visitors, and others can stumble upon them every day.

I wonder if those who see the Breguet dial telegraph draw connections to modern technology. The set of characters on computer keyboards, for example, vary from place to place and language to language. I remember attending a student conference in Istanbul in 1998 and being unable to access my email. I didn’t realize that Turkish keyboards have both a dotless and a dotted i key, and so I kept hitting the wrong one. A few months later I met students in Hamburg who were using American keyboards to do their computer programming. They’d discovered that German keyboards of the era required three keystrokes to make a semicolon, which slowed down their coding.

Such tales are good reminders of the persistence and the fluidity of language, which adapts to new technologies just as new technologies are molded by their users.

An abridged version of this article appears in the September 2018 print issue as “The ABCs of Telegraphy.”

Part of a continuing series looking at photographs of historical artifacts that embrace the boundless potential of technology.

About the Author

Allison Marsh is an associate professor of history at the University of South Carolina and codirector of the university’s Ann Johnson Institute for Science, Technology & Society.

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