MORSE CODE

either of two systems for representing letters of the alphabet, numerals, and punctuation marks by an arrangement of dots, dashes, and spaces. The codes are transmitted as electrical pulses of varied lengths or analogous mechanical or visual signals, such as flashing lights. One of the systems was invented in the United States by Samuel F.B. Morse during the 1830s for electrical telegraphy. This version was further improved by Alfred Vail, Morse's assistant and partner. Soon after its introduction in Europe, it became apparent that the original Morse Code was inadequate for the transmission of much non-English text, since it lacked codes for letters with diacritic marks. To remedy this deficiency, a variant called the International Morse Code was devised by a conference of European nations in 1851. This newer code is also called Continental Morse Code. The two systems are similar, but the International Morse Code is simpler and more precise. For example, the original Morse Code used patterns of dots and spaces to represent a few of the letters, whereas the International Morse uses combinations of dots and short dashes for all letters. In addition, the International Morse Code uses dashes of constant length rather than the variable lengths used in the original Morse Code. Except for some minor changes made to it in 1938, the International Morse Code has remained the same and is still in use today for certain types of radiotelegraphy, including amateur radio. The American telegraph industry never abandoned the original Morse Code, and so its use continued until the spread of teleprinters in the 1920s and '30s.