Tests in Newcastle succeeded in sending a quarter of a mile using parallel rectangles of wire. A more practical demonstration of wireless transmission via conduction came in Amos Dolbear's 1879 magneto electric telephone that used ground conduction to transmit over a distance of a quarter of a mile. As telegrams have been traditionally charged by the word, messages were often abbreviated to pack information into the smallest possible number of words, in what came to be called "telegram style". The average length of a telegram in the 1900s in the US was 11.93 words; more than half of the messages were 10 words or fewer. The length of those sending and receiving wires needed to be about the same length as the width of the water or land to be spanned. Building on the ideas of previous scientists and inventors Marconi re-engineered their apparatus by trial and error attempting to build a radio-based wireless telegraphic system that would function the same as wired telegraphy. At the end of 1894, the young Italian inventor Guglielmo Marconi began working on the idea of building a commercial wireless telegraphy system based on the use of Hertzian waves (radio waves), a line of inquiry that he noted other inventors did not seem to be pursuing.

The successful development of radiotelegraphy was preceded by a 50-year history of ingenious but ultimately unsuccessful experiments by inventors to achieve wireless telegraphy by other means. US inventors William Henry Ward (1871) and Mahlon Loomis (1872) developed electrical conduction systems based on the erroneous belief that there was an electrified atmospheric stratum accessible at low altitude. Several wireless electrical signaling schemes based on the (sometimes erroneous) idea that electric currents could be conducted long-range through water, ground, and air were investigated for telegraphy before practical radio systems became available. They thought atmosphere current, connected with a return path using "Earth currents" would allow for wireless telegraphy as well as supply power for the telegraph, doing away with artificial batteries. Currents that flow solely in reaction to these properties, (which together with the resistance define the impedance) constitute reactive power flow, which transmits no power to the load. Fault-sensing protective relays at each end of the line must communicate to monitor the flow of power so that faulted conductors or equipment can be quickly de-energized and the balance of the system restored. Since the pantograph is usually the single point power contact for the locomotive or power car, it must maintain good contact under all running conditions.

1901 large scale application of his ideas, a high-voltage wireless power station, now called Wardenclyffe Tower, lost funding and was abandoned after a few years. A three-phase primary distribution circuit, tapped to feed, via the riser, an underground circuit to a nearby large customer such as a school, hospital, or shopping center. In this design the foil or mesh shield has a circular cross section and the inner conductor is exactly at its center. The neutral is connected to the center tap of the power company transformer of a split-phase system, or the center of the wye connection of a polyphase power system. Apart from only requiring a simple control system for the motors, what is electric cable the smaller size of urban operations meant that trains were usually lighter and needed less power. Also, the relatively short distances that a practical Preece system could span meant that it had few advantages over underwater telegraph cables. All the known effects of electricity-such as sparks, electrostatic attraction, chemical changes, electric shocks, and later electromagnetism-were applied to the problems of detecting controlled transmissions of electricity at various distances.

To reduce the risk of users accidentally touching energized conductors and thereby experiencing electric shock, plug and socket systems often incorporate safety features in addition to the recessed contacts of the energized socket. Both electrostatic and electromagnetic induction were used to develop wireless telegraph systems that saw limited commercial application. This led to speculation that it might be possible to eliminate both wires and therefore transmit telegraph signals through the ground without any wires connecting the stations. A study of these demonstrations of radio, with scientists trying to work out how a phenomenon predicted to have a short range could transmit "over the horizon", led to the discovery of a radio reflecting layer in the Earth's atmosphere in 1902, later called the ionosphere. A person visiting a local telegraph office paid by the word to have a message telegraphed to another office and delivered to the addressee on a paper form.