NMSAT :: Networked Music & SoundArt Timeline

1884 __ Ætheric signalling and wireless telegraphy
Sir William Henry Preece (?-?)
Comment : Could Sir William Henry Preece.scholar, electrical researcher, inventor and lecturer.predict radio broadcasting, color TV, radar, and satellite repeaters, for reliable world–wide communications and navigation? In one of Preece's lecturer at the Royal Institution in 1880, he described the "tremendous" improvement, that Wheatstone's alphabetical telegraphic apparatus had made possible in Great Britain's telegraph network. He reported about 5000 units then in use.an increase from the 1200 units of only 10 years earlier. The eight telegraphic circuits of 1870 had by then grown to the "enormous" quantity of 150, and where earlier equipment could handle only 70 to 80 words per minute, the improved units could carry 150 to 180 words per minute. In his enthusiastic report Preece said the Wheatstone apparatus had reached a peak of perfection."at the head of the world, and the time is not far distant when even America will take advantage of the invention we are now using." In the 1860's and 1870's the very idea of telephony or speech reproduction was equated by the public with supernatural phenomena. Voices that traveled over wires and came out of a box could only be mystical, or the result of insane hallucinations. How would the public react to communication without even the wires? The answer was soon to come. In 1884 messages sent through buried insulated wires.no doubt some carrying press releases of the success of Mark Twain's new novel, “Huckleberry Finn”.were picked up on telephone circuits erected on poles 80 ft above the ground. Telegraph circuits created electrical disturbances in telephone lines 2000 ft away, and distinct speech could be picked up from phone lines as far as a quarter mile away. By 1892 messages were deliberately sent, by such inductive methods, a distance of 3.3 miles across the Bristol Channel in England. On June 4, 1897, Sir William Preece reported to the Royal Institution on progress in "Signaling Through Space Without Wires." His concluding remarks again show the difficulty of farseeing beyond solutions to immediate problems. After tracing the developments of wireless communication from James Clerk Maxwell (1864) and Heinrich Hertz (1887) to Guglielmo Marconi, he concluded, " [...]enough has been done to prove its (wireless') value; for shipping and lighthouse purposes it will be great. Preece observed that many critics claimed: "Marconi invented nothing new; his transmitter was old.not much different from the one Hertz used over 10 years ago and his receiver was based upon Branly's coherer (1890), invented about seven years earlier." Preece, to his credit, nevertheless defended Marconi as a true inventor: "Columbus did not invent the egg, but he showed how to make it stand on its end, and Marconi has produced from known means a new electric eye more delicate than any known electrical instrument, and a new system of telegraphy [...]. ". (“Extending Man's Voice by Wire and Radio”, Based on the bicentennial issue of Electronic Design for engineers and engineering managers, Vol 24, number 4 Feb. 16, 1976)Ætheric signalling and wireless telegraphy are much confounded in popular descriptions, but there is a considerable difference between them. There are two systems of wireless telegraphy, which have proved successful. The first of these is that which has been introduced by that great electrical authority, Sir William Preece. Sir William Preece, whose name is received with respect in every scientific meeting in the world, on account of original research which has made him famous, was for many years the head of the telegraph department of the Post Office, and now is the consulting electrical engineer to the Post Office. Hence, he is the greatest living authority on telegraphy. He has devised a system of wireless telephony. The principle of this system is, that suppose it were desired to effect communication without the medium of a conducting wire between the island the mainland, it would be achieved by stretching along the island and along the mainland two parallel telegraph wires, the ends of which would be sunk either in the sea or in the earth. It has been proved by Sir William Preece that if an electrical current be set up in one of these wires, a corresponding current is induced in the other wire, and that hence the signals transmitted through the first wire are repeated in the second wire. In this case it seems that the electrical effects are transmitted not only by induction between the two wires, but by conduction through the earth in which the terminal plates of the wires are embedded. This system has been established at the island of Flatholm, in the Bristol Channel, where Lloyds' signal station is now connected by wireless telephony with the mainland, over a distance of three miles by sea. Sir William Preece has also established his system at the Skerries Islands off the coast of Anglesea, where communication is effected over two miles of sea, and the Post Office is now establishing this system on behalf of Lloyds' to connect Lloyds' signal station at Rathlin Island, on the north coast of Ireland, with the mainland, over a distance of about seven miles. The experiments which have been made, as Sir William Preece states prove conclusively that communication, both telegraphic and telephonic, has been readily maintained by these means, and that wireless telegraphy across the sea by this method is now a practical and commercial system. He also believes that it would be simple to speak by telephone between ship and shore or between shore and ship at a considerable distance by means of a circuit formed of copper wire passing over the topmasts and terminating at each end of the ship in the sea, using simply telephones. (Sir Henry Montague Hozier, “ÆTHERIC SIGNALLING”, 1901, Journal of the Military Service Institution, vol. XXVIII, No. 110, pp. 256-264)In 1896, when Marconi first went to England, he demonstrated to the late Sir William Preece, then Engineer-in-Chief of the British Post Office, the transmission and reception of intelligible signals over a distance of 1¾ miles, by means of short waves, using reflectors. (“The Book of Radio”, Charles William Taussig, 1922, pp. 288-308 Thomas H. White, “Articles and extracts about early radio and related technologies, concentrating on the United States in the period from 1897 to 1927”)
French comment : Transmission sans fil par induction par William Preece dans l'estuaire de la Severn. (W. Preece in "Select Committee" 1907 cité par Aitken in "Syntony and spark " note 25 p. 287 et "Journ. of the Soc. of Arts, 1894, 23 Feb.)
Urls : http://www.hbci.com/~wenonah/history/edpart3.htm (last visited ) http://www.paleotechnic.com/1889/history/aetheric.shtml (last visited ) http://earlyradiohistory.us/1922euro.htm (last visited ) http://cnum.cnam.fr/CGI/fpage.cgi?P84.7/193/100/667/0/0 (last visited )

No comment for this page

Leave a comment