Charles Sumner Tainter
Charles Sumner Tainter (April 25, 1854 – April 20, 1940) was an American scientific instrument maker, engineer and inventor, best known for his collaborations with Alexander Graham Bell, Chichester Bell, Alexander's father-in-law Gardiner Hubbard, and for his significant improvements to Thomas Edison's phonograph, resulting in the Graphophone, one version of which was the first Dictaphone.
Later in his career Tainter was associated with the International Graphopone Company of West Virginia, and also managed his own research and development laboratory, earning him the title: 'Father Of The Talking Machine' (i.e.: father of the phonograph).
Tainter was born in Watertown, Massachusetts, where he attended public school. His education was modest, acquiring his knowledge mostly through self-education. In 1873, he took a job with the Alvan Clark and Sons Company producing telescopes in Cambridge, Massachusetts, which then came under contract with the U.S. Navy to conduct observations of the transit of Venus on December 8, 1874, resulting in Tainter being sent with one of its observation expeditions to New Zealand. In 1878 he opened his own shop for the production of scientific instruments in Cambridgeport, Massachusetts, where he made the acquaintance of Alexander Graham Bell. A year later Bell called Tainter to what would become his Volta Laboratory in Washington, D.C., where he would work for the next several years. 
During this time, Tainter worked with the Bells on several inventions, amongst them the photophone and phonograph, which they developed into the Graphophone, a substantial improvement of Edison's earlier device, for which Tainter received several patents along with the Bells. Edison subsequently sued the Volta Graphophone Company (of which Tainter was part owner) for patent infringement, but the case was settled by a compromise between the two.
In 1886, he married Lila R. Munro, and over the next years worked in Washington, perfecting his graphophone and founding a company trying to market the Graphophone as a dictation machine: the first Dictaphone. In 1887 Tainter invented the helically wound paper tube as an improved graphophone cylinder. This design was light and strong, and came to be widely used in applications far removed from its original intent, such as mailing tubes and product containers.
In 1888 he was stricken with severe pneumonia, which would incapacitate him intermittently for the rest of his life, leading him and his wife to move to San Diego, California in 1903. After the death of his first wife in 1924, he married Laura F. Onderdonk in 1928. Tainter received several distinguished awards for his graphophone.
In 1947 Tainter's widow, Laura Fontaine Onderdonk, donated a number of Sumner Tainter's unpublished writings, including the surviving Home Notebooks, to the Smithsonian Institution's National Museum of American History.   The Home Notebooks contain daily agendas describing in detail the project work Tainter conducted at the Volta Laboratory during the 1880s. In 1950 Laura Tainter donated other historical items, including Sumner Tainter's manuscripts of "Memoirs of Charles Sumner Tainter", the first 71 pages of which detailed his experiences up to 1887, plus further writings on his work at the Graphophone factory in Bridgeport, Connecticut.