On This Day in Steampunk History - March 7

Alexander Graham Bell patents the telesonophone, a novel device that combines a lightweight telegraph key attached to a pressurized steam amplification chamber that lay between the key and a speaking horn. By amplifying the sound from the speaking horn, the steam-powered membrane drove the telegraph key at such a rate that the impulses on the receiving end would register as sound waves.

In time this device would be simplified and modulated until it became the telesons of today.