This letter from Edison to Olive Logan Sikes, author, actress, lecturer, and journalist, is from July 1878. It contains a discussion of Edison's recently invented megaphone and Sikes's newspaper article on the phonograph. Along with the letter is an undated note from Edison to "friend Murray" (probably inventor and public utility executive Thomas E. Murray) regarding the invention of the incandescent lamp.

Courtesy of the Yale University Library.