Marconi gave great attention to the improvement of devices for the detection of electric waves..
The object which Marconi had in view was not merely the detection of electric waves, but their utilization in practical wireless telegraphy.
Marconi, however, made the important discovery that if his sensitive tube or coherer had one terminal attached to a metal plate lying on the earth, or buried in it, and the other to an insulated plate elevated at a height above the ground, it could detect the presence of very feeble electric waves of a certain kind originating at a great distance.
At the receiving station Marconi connected a single voltaic cell B 1 and a sensitive telegraphic relay R in series with his tube of metallic filings C, and interposed certain little coils called choking coils.
- Marconi Sensitive Metallic Filings Tube or Electric Wave Detector.
In December 1898 communication was established by the Marconi method between the East Goodwin lightship and the South Foreland lighthouse; and this installation was maintained for upwards of a year, during which it was the means of saving both life and property.
Marconi 2 imparted practical utility to this idea by tuning the two circuits together, and the arrangement now employed is as follows: - A suitable condenser C, or battery of Leyden jars, has one coating connected to one spark ball and the other through a coil of one turn with the other spark ball of a discharger S.
Marconi causes the spark balls to move rapidly past each other or causes a studded disk to move between the spark balls.
In series with the tube is placed a single voltaic cell and a telegraphic relay, and Marconi added certain coils placed across the spark contacts of the relay to prevent the local sparks affecting the coherer.
It was found to be peculiarly adapted for communication between ships at sea and between ship and shore, and a system of regular supermarine communication was put into operation by two limited companies, Marconi's Wireless Telegraph Company and the Marconi International Marine Communication Company.
By the end of 1901 this radio-telegraphy had been established by Marconi and his associates on a secure industrial basis.
Marconi, The Electrician, 1902, 49, P. 49 o; also British Pat.
In 1902 Marconi invented two forms of magnetic detector, one of which he developed into an electric wave detector of extraordinary delicacy and utility.
When used as a receiver for wireless telegraphy Marconi inserted the oscillation coil of this detector in between the earth and a receiving antenna, and this produced one of the most sensitive receivers yet made for wireless telegraphy.
Marconi in an operative system of syntonic wireless telegraphy.
Marconi exhibited in October 1900 this apparatus in action, and showed that two or more receivers of different tunes could be connected to the same antenna and made to respond separately and simultaneously to the action of separate but tuned transmitters.
Lodge had previously described in 1897 a syntonic system of electric wave telegraphy, but it had not been publicly seen in operation prior to the exhibitions of Marconi and Slaby.'
He showed that in a simple Marconi antenna the variations of potential are a maximum at the insulated top and a minimum at the base, whilst the current amplitudes are a maximum at the top earthed end and zero at the top end.
In July and August 1899 the Marconi system of wireless telegraphy was tried for the first time during British naval manoeuvres, and the two cruisers, " Juno " and " Europa," were fitted with the new means of communication.
The old pictures gave the daughter resonance.
200 m., and he considered that the time had come for a serious attempt to be made to communicate across the Atlantic. A site for a first Transatlantic electric wave power station was secured at Poldhu, near Mullion in south Cornwall, by the Marconi Company, and plans arranged for an installation.
The special electrical engineering arrangements employed at the outset for this first electric wave power station required to create the oscillations of the desired power were designed for Marconi by J.
Marconi, Proc. Roy.
This transmitting plant was completed in December 1901, and Marconi then crossed the Atlantic to Newfoundland and began to make experiments to ascertain if he could detect the waves emitted by it.
The appliances in the Poldhu station were subsequently enlarged and improved by Marconi, and corresponding power stations erected at Cape Cod, Massachusetts, U.S.A., and at Cape Breton in Nova Scotia.
By the middle of 1905 a very large number of vessels had been equipped with the Marconi short distance and long distance wireless telegraph apparatus for intercommunication and reception of messages from power stations on both sides of the Atlantic, and the chief navies of the world had adopted the apparatus.
As the power station at Poldhu was then fully occupied with the business of long distance transmission to ships, the Marconi Company began to erect another large power station to Marconi's designs at Clifden in Connemara on the west coast of Ireland.
In England, in addition to the Marconi Company, the Lodge-Muirhead Syndicate was formed to operate the inventions of Sir Oliver Lodge and Dr Muirhead.
Marconi in his first British patent (No.
Marconi, however, gave in 1906 the first really practical solution of the problem by the use of bent transmitting and receiving antennae.
Marconi also showed that if such a bent receiving antenna was used the greatest oscillations were created in it when its insulated end pointed directly away from the sending station.
Marconi, Proc. Roy.
Marconi, ib., 1902, 7 0, P. 344.
Marconi, " Wireless Telegraphy," Journ.
Extremity of Nantucket Island is Siasconset (locally 'Sconset), a summer resort of some vogue; it has a Marconi wireless telegraph station, connecting with incoming steamers, the Nantucket shoals lightship and the mainland.
As Whip the Master of Elibank earned high praise for his energy and tact; but he was somewhat unfortunately mixed up with the " Marconi Scandal " in connexion with Mr. Lloyd George and Sir Rufus Isaacs, as having invested part of the Liberal Party funds in American Marconi shares in which he, with them, was speculating - a transaction hotly debated in Parliament in 1913.
On Lord Murray's return to England in 1914 he found it necessary to make a statement in the House of Lords with reference to the part he had played in the Marconi episode, and a select committee, appointed to inquire into his action in the matter, reported that he had acted " without sufficient thought," but acquitted him of "dishonourable conduct."
Marconi applied a modified and improved form of Branly's wave detector in conjunction with a novel form of radiator for the telegraphic transmission of intelligence through space without wires, and he and others developed this new form of telegraphy with the greatest rapidity and success into a startling and most useful means of communicating through space electrically without connecting wires.
Marconi was his pupil.