Telecommunication
The conventional telephone was invented independently by Alexander Bell and Elisha Gray in 1876. Antonio Meucci invented the first device that allowed the electrical transmission of voice over a line in 1849. However Meucci's device was of little practical value because it relied upon the electrophonic effect and thus required users to place the receiver in their mouth to "hear" what was being said. The first commercial telephone services were set-up in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London.
Pavel Golubitzky
Major inventions took place in the 1880s. In 1882 he designed a multi-pole phone. By this time the phone line was already organized in many cities around the world. However, it was of poor quality, and in 1883 at the Munich electrical exhibition of the expert Commission was given the conclusion that the system used "is suitable for the transmission of sound at distances up to ten kilometers."