Morse Code is named after Samuel Morse, who was the first to develop a system to represent letters of the alphabet with 'dots' and 'dashes'. Morse Code enables messages to be transmitted from one person to another via electrical signals, flashes of light, bursts of sound, or any other mechanism that can generate two different symbols¹.

Samuel Morse was born in 1791 in Charlestown, Massachusetts. He studied at Yale in Connecticut and learned about electricity there. He studied art in England between 1811 and 1815 and made a living after that as an artist and teacher. In 1837, he was an art teacher at the university in New York City, but had been continuing to think about electricity. Utilising the expertise of colleagues Leonard Gale and Joseph Henry, he built an electric telegraph - a device that enabled encoded messages to be sent along wires. Much of the material for the project was provided by his friend Alfred Vail, whose family owned an ironworks in New Jersey.

In the early 1830s, the 'bi-signal' codes that had been developed for sending messages used electromagnetism to turn a needle either to the right or to the left in patterns corresponding to letters of the alphabet. The code developed by Morse and Vail in 1838, on the other hand, used short and long signals that could be recorded more quickly than by watching a needle.

The original Morse Code had the same signals for g and j, for i and y, and for s and z. As well as requiring spaces between the signals for each letter, it sometimes required spaces within the signal for a letter. This meant that the signals for ce and eg were the same, for example. An improved version was produced in 1844, with distinct codes for all letters. However, there were still some spaces within letter codes so, for example, the signals for o and ee were the same.

International Morse Code was developed in 1851. It does not include spaces within letters. It assigns shorter codes to the more commonly-used letters. It also enables letters with diacritical marks, such as é and ñ, to be encoded.

Alfred Vail died in 1859 and Samuel Morse died in 1872, but Morse Code and the telegraph system they pioneered went on to gain great importance in the 20th Century as a method of communication during wartime and in peace time³. Two Morse Code signals you may be familiar with are: SMS⁴ (• • • − − • • •), the default sound the earliest Nokia mobile phones made when an SMS text message was received, and the distress signal SOS (• • • − − − • • •).

Further reading:

• Andrew Carnegie: Steel, Money and Culture - Carnegie was able to listen to Morse code and translate it in his head when he worked for the Ohio Telegraph Company.
• Dorothy O'Grady: Dotty Dog Walker or Secretly Sandown's Sinister Seaside Super Spy? - O'Grady was accused of using a light to send Morse Code messages to German aeroplanes during World War II.
• Cryptography - Codes and the Zimmermann Telegram - this Entry notes that Morse Code is actually a cipher, not a code, as it substitutes dots and dashes for letters rather than replacing words with other words.
• The Disappearance of Amelia Earhart and Frederick Noonan - Earhart disliked using Morse Code, and this perhaps contributed to her disappearance.
• Finding Your Way Back To Civilisation - if you get lost, you can use Morse Code to send a distress signal.