For the story of the telegraph and its inventors, see: S.I.Prime, "Life of Samuel F.B.Morse" (1875); S.F.B.Morse, "The Electro-Magnetic Telegraph" (1858) and "Examination of the Telegraphic Apparatus and the Process in Telegraphy" (1869); Guglielmo Marconi, "The Progress of Wireless Telegraphy" (1912) in the "Transactions of the New York Electrical Society", no.

15; and Ray Stannard Baker, "Marconi's Achievement" in McClure's Magazine, vol.XVIII (1902).

On the telephone, see Herbert N.Casson, "History of the Telephone" (1910); and Alexander Graham Bell, "The Telephone" (1878).

On the cable: Charles Bright, "The Story of the Atlantic Cable" (1903).

For facts in the history of printing and descriptions of printing machines, see: Edmund G.Gress, "American Handbook of Printing" (1907); Robert Hoe, "A Short History of the Printing Press and of the Improvements in Printing Machinery" (1902); and Otto Schoenrich, "Biography of Ottmar Mergenthaler and History of the Linotype" (1898), written under Mr.Mergenthaler's direction.