{ ' u Lf ow Marconi Has Conder | Revealing the Secret of the Wireless Wizard's New "One- Way" Radio Which May Supplant Light Buoys and ND now the radio lighthonse! 4 real lighthouse, set like a tower on the rocky coast, with gearch- Hight and revolving redectors, sweeping be sen in every dbwciion with its flashes, Jast as lighthouses have done in the past, But sending out invisible =adio weaves ia stead of rave of Iyht. A lightliouse whose reys will plerce the . thickest fog and enable a distressed ship Lo And its bearings, even though the ship's own radfo transmifitng apparatus has been put out of business by wreck or storm. This is the latest inventiom of Signor Guglielmo Marconi, which he described fully in a receat lecture before the Amer jean Institute of Blecirical Eng'seera and i the Institute '6¢ Radio Engineers in New York. : The "Secret" of this remarkable new invention has just been fully revealed by Signor Marconi. The statements in this article are based on his own explanation radio is based on an . vention by which short wavelengths are reflector and lens. the short-wave radio ight vibrations. By device a different code i Other Signal Devices Guiding Ships at Sea Photograph of Pacific coasts. The other fs called the "Radio Beacon," and is operated at a num ber of points along the Atlantic coast by the United States Department of Com- merce. In the case of the radio compass system, however, a ship, in order to get its bear ings, nu have both a transmitting ap The 100p tver @& circular coil of wire (shaped like an ordinary cof} of rops) eave Ed8EsE, ri he prebiitn that they could not affect any receiver which happened to be out of the angle ot Projection of the beam. "I also described the tests carried out in transmitting a beam of reflected waves across country over Salisbury Plain in England, and pointed ont the possible util ity of such a system if applied to light: houses and lightships. "Following those early tests, practically no research work was carried on for years along these lines. The investigation was taken up by me again in 1916, and since that time I have been most valuably as- sisted by Mr. C. 8. Franklin. "Experiments in Italy showed that goo1 directional working-could be obtained with reflectors properly proportioned in respect to the wave length employed. The tests were continued in England and at Carnar- von, Wales. With an improved com- pressed airspark gap transmitter, a three- meter wave and a reflector having an ap- erture of two wave lengths, a range of wver twenty miles was readily obtained. (The range has since been more thaa doubled.) . "Experiments carried out 4 With revolv- i ing reflectors, which make it easy to read measurements at any distance, prove thal ' the polar diagram for a given reflector and wave length is "Jractically constant at all ranges. "The results obtained by re- appeared to be so good that I was tempted to try out my old idea of twenty-six years ago, and test the system as 4 position finder for ships Near dangerous points. This is now being done in Scotland through the courtesy of Messrs. D. and C. Stevenson and of .. the Commissioners on Northern Lights. Trials are being car ried out under the supervision 'of Mr. Franklin with a revolv- reflector erected at Inch- « keith Island, in the Firth of Forth, near Edinburgh. The , transmitter and reflector re- .Yolving act as a kind of wire less lighthouse or beacon, and _by means of the revolving beam of electrical radiator it is possible for ships, when within a certain distance, to ascertain, in thick weather, *the 3, Josition of the lighthouse, The arimental revolving reflector, was erected and the first tests were carried out with the S. S. Pharos during the Autumn of 1920. "The reflector was caused to make a complete ravolution every two minutes and a distinctive sig- nal was sent every half point of , the compass. It was ascertained = the Steamer that Sin 4 enabled bearing of the transmitter to accurately The Radio Lighthouse of the Future Showing the Revolving Aerial | Wings from Which Radio Code Letters Are' Projected, There Bejing a Distinguishing Letter for Each Different Point of the Compass, and Sectional Interior View Indicating, on Top Floor, Motor Control Room; Floor Below, Reflector Roomy Containing Marconi's Ingenious Mechanical Device for Automatically Projecting Varying Radio Letters as the Wings Revolve; Floor Below, Radio Room; Floors Below, Stores, Sleeping Quarters, Elevator, ete,