Morse code: dots, dashes and the telegraph's first message

On 24 May 1844 a room in the Capitol in Washington hosted a demonstration that would change communication. Samuel Morse sent along a telegraph line to Baltimore a phrase taken from the biblical book of Numbers: “What hath God wrought”. Alfred Vail, his collaborator, received it and sent it back. The age had begun in which a message could travel faster than any courier.

A painter turned inventor

Samuel Finley Breese Morse, born in 1791 in Massachusetts, was for most of his life a painter of portraits and historical subjects, and taught art at the University of the City of New York. According to the traditional account, the idea of the telegraph came to him in 1832, on the voyage home from Europe, while talking with other passengers about electromagnetic experiments. In the following years he worked on the project with Leonard Gale and Alfred Vail.

Vail's contribution to the code was probably important, although his exact share is debated. Morse's initial system involved numbers to be looked up in a dictionary; the version with letters represented by combinations of short and long pulses, which gives the shortest signs to the most frequent letters of English, arose from the collaboration between the two. According to a well-known tradition, the frequencies were estimated by counting the type in a printer's cases.

A code, not a cipher

It is important to make a distinction: Morse is not a system of secrecy. It is a transmission code, that is a public and conventional way of representing letters with electrical, sound or light signals. Anyone who knows the table can read it. For this reason those who wanted confidentiality had first to encipher the message and then transmit it, or use the great commercial codes, which replaced whole phrases with conventional words to save on the cost of telegrams.

From American Morse to International Morse

The original code, known as American Morse, contained internal spaces and signs of different lengths that made it ill-suited to European languages. In 1848 the German Friedrich Clemens Gerke proposed a simplified version, which was adopted in the German-speaking area. On this basis, with some changes, International Morse was born, adopted in 1865 at the Paris telegraph conference, from which the International Telegraph Union originated.

With radio, at the beginning of the twentieth century, Morse became the language of ships. The Berlin Radiotelegraph Conference of 1906 adopted the distress signal made of three dots, three dashes and three dots, which reads SOS but is not the abbreviation of any phrase. In 1912 the Titanic's operators sent both the old CQD signal and the new SOS, helping to make it famous throughout the world.

A language that survives

In 1999 the global maritime distress system moved to satellite and digital communications, and Morse ceased to be compulsory on board. It survives, however, among radio amateurs, in some identification signals for air navigation and in collective memory. Its rhythm of short and long sounds was one of the first technical languages based on the combination of a few elementary signs.

Placed within a history of ciphers, Morse reminds us that not every unusual alphabet hides a secret. Some are created to be understood by everyone, as quickly as possible. And it was precisely the universal spread of the code that made it, in turn, the carrier of countless ciphered messages during the two world wars.