Wireless Telegraphy.

Manawatu Herald, 14 June 1898, Page 2

Wireless Telegraphy.

— » Tho latest of modern scientific miracles is developing apace. The feat of telegraphing without wires is now a proved success and will shortly be pufc to practical effect. The Timet contains a report of some extremely interesting experiments made during the last few months nnder the direc* tion of Signor Mabconi. Two stations have been fitted op— one in Bournemouth and the other at Alum B. y in the Isle of Wight— and between these places, which are about fourteen and a half miles apart, regular communication has been maintained. On occasion an even greater distance has been traversed, for with portable instruments temporarily set up. at Swanage it has betn found possible to speak wifch the station at Alum Bay nearly eighteen miies away. Encouraged by these facts, / Siguor Marconi, when the mail left, was makiog arrangements for exchanging signals at Cherbourg, some sixty miles away. A full description of fche way in which the signals arc conveyed would probably be rather too technical to reproduce here. Suffice ifc to say tbat all that is to be seen externally at each station, instead of tbe usual posts and connection wires, ia a tall mast soma 120 feet high, from whioh depends a metallic conductor. Sometimes this' is a simple wire ;at other times a narrow sti ip of ordinary wire netting hi_ been used. At the sending sfcati vi, by m nm_ ofa battery, an inducti- n coil and two brass balls, electro m.i gnetic waves are created^* radiate in ali direction;. Tbese affect su.ci.s_i veiy thj external conductor at thd receiving station, and then an in .iruu.. Nt in_id«, called a coherer, which in ita turn works a Mor. c priii ier, and thiu tha elscfcroni -_?;.. tic wavd- are converted into vi-i't»:« language. ■N i only can the system be used for c mv. yiog mossage? between two station-, iy paint"', bu 1 ; it has beep sue.. '--f.iMy employed' to communi* o-t with a vessel cruising abput be-tw.-.n rh-I.!e of Wight and Swan* n%-.*. In every case, we are told, c m.muuication was easily maintained v hc-ther the ship was moving forwards or backwards, or swinging round. Ifc is a remarkable fact that the instrument worked mosfc freely in fog, rain or wind; and was at its worst on fine, clear days. Obviously one . practical use to wbich the invention is likely to be put is to establish communication between the shore and outlying lighthouses and lightships. Its employment in fcime of war for keeping up communication between an ad* m'ral and the various vessels of his squadron also naturally suggests itself. Here, however, a difficulty crops up. The electrical waves, as we have said, radiate in all directions, and may be trapped wherever a receiver is set np to intercept them. Consequently, a message intended by the admiral for one of his captains might be read by fche enemy. This is a difficulty which is being grappled witb. Electric waves, like those", f light oan be reflected, hence it is Believed the messages oan be direoted towards the quarter which it is desired they should reaoh and prevented from radiating in other directions. Yefc another principle may be employed to secure secrecy. This is what is called syntony. If a tuning fork is struck, another tuning wt close by will vibrate in sympathy witb ifc, if it is of the same pitch, bufc not otherwise. It is the same with the Mabconi sender and receiver. If tbey are not " in tune " the waves sent from one will not set up vibrations in the other. It is hoped, therefore, by adopting differences in tuning that a oertain amount <tfi secrecy may be arranged for. Altogether tho latest " fairy tale " of science is full of fascination, and we .hall watch with intense interest the uuf oldiog of succeeding chapters.