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.
Elisha Gray and Alexander Bell telephone controversy
After largely abandoning his telephone experiments, fourteen months later on February 11, 1876, Gray . On February 14, Gray's lawyer with a similar diagram. The same day, Bell's lawyer filed (hand-delivered to the U.S. Patent Office) a patent application on the harmonic telegraph, including its use for transmitting vocal sounds. On February 19, the patent office suspended Bell's application for three months to give Gray time to submit a full patent application with claims, after which the patent office would begin interference proceedings to determine whether Bell or Gray were first to invent the claimed subject matter of the telephone.