. Bulletin. Science. NEW YORK BOSTON. ^-^-H|i|i|i|il^!i|iiiHi|i|,|iji|,iili]i|ip Uiiii!i|iii!iiiii|iii|i|iii|iHi|i|iiih Figure 48.—Western Union's first practical quadruplex circuit, 1874. From G. B. Prescott, The Speaking Telephone, New York, 1878, p. 311. ^l/Jhr Jw dUl^^tttiiW \ Z^^. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Smithsonian Institution; United States. Dept. of the Interior; United States National M

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. Bulletin. Science. NEW YORK BOSTON. ^-^-H|i|i|i|il^!i|iiiHi|i|,|iji|,iili]i|ip Uiiii!i|iii!iiiii|iii|i|iii|iHi|i|iiih Figure 48.—Western Union's first practical quadruplex circuit, 1874. From G. B. Prescott, The Speaking Telephone, New York, 1878, p. 311. ^l/Jhr Jw dUl^^tttiiW \ Z^^. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Smithsonian Institution; United States. Dept. of the Interior; United States National Museum. Washington, Smithsonian Institution Press, [etc. ]; for sale by the Supt. of Docs. , U. S. Govt Print. Off

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Keywords: ., bookauthorunitedstatesdepto, bookcentury1900, booksubjectscience