One of Thomas Edison's little-known ambitions was to build a device to hear the voices of the dead, according to a nearly lost chapter of the inventor's memoirs which is being republished in France this week.
The American, who developed the phonograph and is often cited, inaccurately, as being the first to come up with the light bulb, wanted to create a sort of "spirit phone" that recorded the utterances of departed souls.
Edison (1847-1931) detailed his efforts and they were published posthumously in 1948 as the final chapter of his "Diary and Sundry Observations."
Strangely, though, his account of dabbling in what would today be considered the occult was expunged in subsequent English-language editions of the book.
Some in America thought the idea was maybe a hoax or a joke by Edison, as no design for a "spirit phone" has ever been uncovered.
But in France, the 1949 French translation of inventor's original "Diary" was preserved intact -- with the missing final chapter.
French readers from Thursday will be able to rediscover Edison's unusual quest in a book titled "Le Royaume de l'Au-dela" (The Kingdom of the Afterlife) that republishes the text.
It may not be as he conceived it, but in a way the book channels Edison's words from beyond the grave.
The work is presented with commentary by Philippe Baudouin, a French radio presenter and trained philosopher, who told AFP: "This little-known episode in the history of talking machines was of special interest to me, as I'm a radio man."
The chapter shows how Edison tried in late 1870 to find a basis for his "spirit phone" invention by amplifying the sound from his phonographs, the precursor of gramophones and record players.
He even made a pact with an engineer working with him, William Walter Dinwiddie, that the first who died would "would try to send a message to the survivor from beyond," Baudouin said.
Edison believed not only that ghosts existed but but also that they were very talkative.
He "imagined being able to record the voice of another being, to be able to make audible that which isn't -- the voice of the dead," Badouin said.