Charles Bourseul (28 April 1829 – 23 November 1912) was a pioneer in development of the "make and break" telephone about 20 years before Bell made a practical telephone.
Bourseul was born in Brussels, Belgium, and grew up in Douai, France. His father was a French army officer. Charles worked for the telegraph company as a civil engineer and mechanic. He made improvements to the telegraph system of L. F. Breguet (a French instrument maker ) and Samuel F. B. Morse. Charles Bourseul experimented with the electrical transmission of the human voice and developed an electromagnetic microphone, but his telephone receiver was unable to convert electrical current back into clear human voice sounds.
In 1854 Bourseul wrote a memorandum on the transmission of the human voice by electrical currents that was first published in a magazine L'Illustration (Paris), though no prototype was built. That is about the same time that Meucci later claimed to have created his first attempt at the telephone in Italy.
Bourseul explained: “Suppose that a man speaks near a movable disc sufficiently flexible to lose none of the vibrations of the voice; that this disc alternately makes and breaks the currents from a battery: you may have at a distance another disc which will simultaneously execute the same vibrations.... It is certain that, in a more or less distant future, speech will be transmitted by electricity. I have made experiments in this direction; they are delicate and demand time and patience, but the approximations obtained promise a favourable result.”
Bourseul died in Saint-Céré, France, at the age of 83.