Letter (alphabet) of sounds to make words. A letter is classed as either a consonant or a vowel, depending on how its sound is produced (vowels are "a", "e", "i", "o", "u", and sometimes "y" and "w"). The basic Roman alphabet is used by about one hundred languages, with slight variations. Some versions contain as few as twenty-one characters, some as many as thirty. Letters have specific names associated with them, which may differ with language, dialect, and history. "Z", for example, is usually called "zed" in all English-speaking countries except the US, where it is named "zee". As elements of alphabets,
American Morse code in Baltimore is on display in the Library of Congress in Washington, D.C. In its original implementation, the Morse Code specification included the following: Various other companies and countries soon developed their own variations of the original Morse Code. Of special importance was one standard, originally created in Germany by Friedrich Clemens Gerke in 1848, which was simpler—it eliminated the long intra-character spaces and the two long dashes—but also included changes in the sequences for eleven of the letters and most of the numerals. The Gerke code had a distinct advantage for use on undersea telegraph cables. Cables suffer from