De Locht Pantelephone

Invented by Leon de Locht-Labye, a professor at the University of Liège in Belgium around 1879–1880, the Pantelephone was an early and highly sensitive telephone transmitter designed to bypass the restrictive patents held by Alexander Graham Bell. Instead of a small metal disc, the Pantelephone used a large, suspended sheet (roughly 15 cm square) made of cork, mica, or thin metal. This large surface area allowed it to pick up vibrations from across a room. De Locht-Labye specifically designed the Pantelephone to offer a cheaper, more effective alternative to Bell’s system. However, it eventually ran into legal trouble regarding Thomas Edison’s carbon transmitter patents (which had been acquired by Bell).