Invention of the telephone useful and widespread apparatus it is now. The telephone exchange was an idea of the Hungarian engineer Tivadar Puskás (1844–1893) in 1876, while he was working for Thomas Edison on a telegraph exchange. Puskás was working on his idea for an electrical telegraph exchange when Alexander Graham Bell received the first patent for the telephone. This caused Puskás to take a fresh look at his own work and he refocused on perfecting a design for a telephone exchange. He then got in touch with the U.S. inventor Thomas Edison who liked the design. According to Edison, "Tivadar Puskas was the
Reis telephone an advanced version where the iron bar is clamped to a cigar-box-shaped resonator. This receiver is not very sensitive. It produces weak sound but has good fidelity. It requires very high current and is a current-sensitive device rather than a voltage-sensitive device. This instrument could transmit continuous musical tones but produced indistinct speech. In 1865, however, British scientist David E. Hughes used the Reis telephone with "good results". Reis telephone The Reis telephone was an invention named after Philipp Reis of a telephonelike device he constructed. Reis's first successful work is dated to October 1861. In 1861, Philipp Reis succeeded