Description of the Electro Magnetic Telegraph: Now in Operation Between the Cities of Washington and Baltimore

Washington, D.C.: J. & G. S. Gideon, 1845. First edition. Illustrations. 24pp. 8vo. Publisher's green lettered wrappers, minor soiling and staining. First edition. Illustrations. 24pp. 8vo. "When in 1843 Congress approved the construction of an experimental telegraph line between Baltimore and Washington, Vail acted as Morse's chief assistant and received Morse's 'What hath God Wrought' message on May 24, 1844 ... [The present pamphlet] containts one of the earliest prints of the 1844 revision of Morse's telegraphic code, which, under the name 'American Morse' became the standard code for use within the United States and Canada. The Morse code was the first widely adopted data code" (Hook & Norman). Howes V5; Sabin 98292; Hook & Norman, Origins of Cyberspace 208