Sometimes the importance of an invention is overlooked. This apparatus is an example thereof. Whereas, in 1876, Alexander Graham Bell created a furore as well as a fortune with his patent on the telephone, this 15 years older apparatus of the German researcher Philipp Reiss has never been taken seriously. Nevertheless, Reiss’ telephone was in fact capable of the same things as Bell’s invention later on, that is, it could transmit sound over a long distance through an electric current. To reproduce the sound, Reiss uses the characteristic feature that an iron rod expands when it is magnetized in a coil. When the current is cut off, the rod assumes its normal length. The resulting vibration generates sound waves, which are amplified in a sound box.
