The Franklin Institute Logo
Case Files logo

Guglielmo Marconi: Application of Radio Waves to Communication, 1918

Beyond Visual Range

Marconi first approached the Italian Ministry of Posts and Telegraphs to demonstrate the advantages of his wireless method versus the existing system of land-based cables and met with no success. Switching his attention to the United Kingdom, Marconi used his family connections in London who put him in contact with British experts, who in turn introduced him to Dr. William Preece, Chief Engineer of the General Post Office. Preece, who had himself been experimenting with alternative transmission methods, was very cooperative and helpful. He offered Marconi any necessary working space and assisted at the first public demonstration of wireless telegraphy. During this time, work was proceeding on the patent application titled "Improvements in Transmitting Electrical Impulses and Signals, and an Apparatus therefore." The patent was filed on June 2, 1896, and finally published as British Patent No.12039 on March 2, 1897. In July 1896, the transmission range had grown to 400 meters and newspapers had published news of the discovery to wide acclaim.

Trials were made which demonstrated the efficiency and dependability of wireless transmission across open water, opening up the possibility of dispensing with underwater cables. Observers from the maritime services were impressed; up to that time communication between ships at sea was limited to visual signals, either semaphore flags or signal lights that could be obliterated by fog. Now messages could be transmitted beyond visual range.

Among the audience were observers from Italy who now reversed themselves and asked that Marconi demonstrate his invention in his native land. The result showed successful transmission from La Spezia Naval Base over 18 kilometers to a ship at sea; the barrier of communication over the horizon to a receiver out of sight was surpassed in July 1897. Marconi, at the age of 23, was hailed as a national hero.

In 1897, the Wireless Telegraph and Signal Company, the forerunner of Marconi's Wireless and Telephone Company, was established in London and connections to the nationally owned General Post Office were ended.