THE Marconi system of wireless tele- graphy aMr. MARCONI is still engaged in further developing this part of his invention, and if he is able to overcome the liability of messages to get into wrong hands or to be otherwise interfered with, his system will certainly be much more practically serviceable than it now is.

It has been thought, and practical trial has confirmed the idea, that the wireless system would be invaluable for communi- cating between lightships or outlying lighthouses and the shore. At present this is accomplished with more or less success by means of submarine cables, which are necessarily costly to lay and to maintain. But the trial of the system of etheric communication between the East Goodwin Lightship and the South Foreland proved a complete success.

Here were two fixed points, eleven miles apart, between which it was demon- strated that communication could be at all times easily maintained. For the ordinary purposes of the lighthouse service the system would no doubt be most useful, but the chief expectation of its utility would be that by its agency information of any vessel in distress in the vicinity could be promptly com- municated to the land, and the necessary assistance expeditiously sent off. For use in this respect we trust the system may ere long be permanently established at many stations. For conveying warn- ing signals in foggy weather from salient posts on the coast, it is not so clear that the Marconi apparatus could be effectu- ally employed. In such conditions the essence of the warning to be conveyed to the mariner is to let him know where he is relatively to the signalling station, and about how far distant he is from it.

But this is information which cannot at present be given by the wireless system with any approach to accuracy, notwith- standing Mr. MARCONI'S ingeniovis attempts to concentrate the electric waves into a kind of beam and send them out only in a given direction, so that they should be receivable only within a certain arc. It is difficult to understand that a receiving instrument can give any indication as to where the wave motion was generated, or, in other words, the direction from which the message was despatched. As Lord RAYLEIGH has stated, it is of no use merely to be told by a message that such and such a signalling station exits, and if the wireless system can. do no more than this it is useless for conveying signals to mariners in foggy weather.

Moreover, the question of distance is an important one. According to present knowledge it does not appear possible for the wireless message to convey any idea whatever of the distance of its originating source, and in a fog a mariner would, therefore, get no assistance in judging his distance from the signal station or fixing his position. These are serious deficiencies in respect of the use of the system for coast fog - signal purposes, but Mr. MARCONI is quick- sighted and persistent, and may in time even overcome these difficulties.

ppears to be slowly moving out of the experimental stage of develop- ment. Undoubtedly the project is full of splendid possibilities, and the talented inventor is doing his best to realise them and to bring his process within the range of practical politics. For maritime purposes the Marconi process seems peculiarly adapted to be of service, so often is it desirable in connection with navigation and shipping to send messages across long distances. Its utility as at present developed is recognised in the British Navy, there being no fewer than forty of H.M.'s ships fitted with wireless telegraphy installations, whereby the ships of a fleet can hold converse with one another, or receive orders from head- quarters on shore. The war vessels of the Italian Navy are also being equipped with the Marconi apparatus for signal- ling purposes, and it is probable that the naval authorities of other countries will before long adopt the system.

Lloyd's are making use of it successfully for many of their signalling stations, and about twenty of the Transatlantic liners are equipped with the Marconi apparatus, of which many passengers are glad to avail themselves on leaving or approaching the shores of England or the United States. In addition to this the Admiralty have recently issued a notice to mariners, intimating that the Marconi Wireless Telegraph Company have established stations at Frinton-on- Sea (Essex), North Foreland, Niton (Isle of Wight), Poole Haven, Lizard, Holy- head, on the English Coast; at Rosslare, ' * From The Shipping and Mercantile Gazette, August 28, 1902.

Crookhaven, Malin Head, and Inishtra- hull, in Ireland ; at Borkum, Germany ; Nieuport,Belgium; Belle Isle, Labrador; Chateau Bay, Labrador; and Sagapo- nack, Long Island, U.S.A.; where messages can be received and forwarded to their destinations. In the various services above referred to the application of the wireless telegraph system is of a simple character, consisting merely of the direct transmission from one point to another of messages across intervening spaces. This is, of course, in itself a splendid achievement, and may be at times of the greatest service, but it must be borne in mind that the messages so sent would be liable to be read by others besides those for whom they were intended. In this respect, however, Mr. MARCONI has made some advance beyond the capabilities of his earlier apparatus. He is now able to regulate the length of the electric waves generated by a transmitter, and to adjust the receiving instrument to respond only to waves of a certain length. With this arrangement a private conversation can be carried on, intelligible only to the parties concerned, unless in the vicinity there is another pair of instruments giving off and receiving electric waves of the same length, in which case there might be some confusion. Mr. MARCONI also states that he is now able to connect to the vertical sending wire several differently tuned transmitters, and to the receiving vertical wire a number of correspondingly tuned receivers, thus enabling different messages to be sent by one transmitter simultaneously, and to be received also simultaneously by the correspondingly tuned receivers.Mr. MARCONI is still engaged in further developing this part of his invention, and if he is able to overcome the liability of messages to get into wrong hands or to be otherwise interfered with, his system will certainly be much more practically serviceable than it now is.

It has been thought, and practical trial has confirmed the idea, that the wireless system would be invaluable for communi- cating between lightships or outlying lighthouses and the shore. At present this is accomplished with more or less success by means of submarine cables, which are necessarily costly to lay and to maintain. But the trial of the system of etheric communication between the East Goodwin Lightship and the South Foreland proved a complete success.

Here were two fixed points, eleven miles apart, between which it was demon- strated that communication could be at all times easily maintained. For the ordinary purposes of the lighthouse service the system would no doubt be most useful, but the chief expectation of its utility would be that by its agency information of any vessel in distress in the vicinity could be promptly com- municated to the land, and the necessary assistance expeditiously sent off. For use in this respect we trust the system may ere long be permanently established at many stations. For conveying warn- ing signals in foggy weather from salient posts on the coast, it is not so clear that the Marconi apparatus could be effectu- ally employed. In such conditions the essence of the warning to be conveyed to the mariner is to let him know where he is relatively to the signalling station, and about how far distant he is from it.

But this is information which cannot at present be given by the wireless system with any approach to accuracy, notwith- standing Mr. MARCONI'S ingeniovis attempts to concentrate the electric waves into a kind of beam and send them out only in a given direction, so that they should be receivable only within a certain arc. It is difficult to understand that a receiving instrument can give any indication as to where the wave motion was generated, or, in other words, the direction from which the message was despatched. As Lord RAYLEIGH has stated, it is of no use merely to be told by a message that such and such a signalling station exits, and if the wireless system can. do no more than this it is useless for conveying signals to mariners in foggy weather.

Moreover, the question of distance is an important one. According to present knowledge it does not appear possible for the wireless message to convey any idea whatever of the distance of its originating source, and in a fog a mariner would, therefore, get no assistance in judging his distance from the signal station or fixing his position. These are serious deficiencies in respect of the use of the system for coast fog - signal purposes, but Mr. MARCONI is quick- sighted and persistent, and may in time even overcome these difficulties..