细节
EDISON, Thomas Alva (1847-1931). Typed letter signed ("Thos A Edison") to an unidentified correspondent, New York, N.Y., 12 August 1886. One page, 4to, on personal letterhead. Boldly signed, with "umbrella" signature.
IMPROVING THE TELEGRAPH. Edison announces an invention to improve the technology of the telegraph: "I have forwarded to you ... a short description of my Phonoplex System of Telegraphy. This system will enable you to duplicate your way wire circuits and to add way circuits to your existing through wires, without any further investment in connection with line construction. With its assistance you can also introduce intermediate stations on duplex and quadruplex wires ... I ... feel confident that ... you will recognize the value of the invention to your company..."
Following the first successful telegraph, Edison had introduced successive improvements, the most significant being duplex and then quadruplex technology (in 1874), which allowed multiple signals to travel the same wire: "The quadruplex was surely the most complicated job Edison had done thus far ... He had to use the most elaborate circuits--combining strong and weak currents with rapid changes in the direction of their flow--that were ever attempted in the era before electronic science was born" (M. Josephson, Edison, p. 123).
IMPROVING THE TELEGRAPH. Edison announces an invention to improve the technology of the telegraph: "I have forwarded to you ... a short description of my Phonoplex System of Telegraphy. This system will enable you to duplicate your way wire circuits and to add way circuits to your existing through wires, without any further investment in connection with line construction. With its assistance you can also introduce intermediate stations on duplex and quadruplex wires ... I ... feel confident that ... you will recognize the value of the invention to your company..."
Following the first successful telegraph, Edison had introduced successive improvements, the most significant being duplex and then quadruplex technology (in 1874), which allowed multiple signals to travel the same wire: "The quadruplex was surely the most complicated job Edison had done thus far ... He had to use the most elaborate circuits--combining strong and weak currents with rapid changes in the direction of their flow--that were ever attempted in the era before electronic science was born" (M. Josephson, Edison, p. 123).