John Yeates Nelson

The announcement of successful wireless telegraphy experiments at the Sydney General Post Office by Philip Billingsley Walker, Watkin Wynne and John Yeates Nelson was very widely reported around Australia and, despite the relatively short distance involved, represented a major step forward for the Colony of New South Wales. The Sydney Daily Telegraph of 11 August 1899 comprehensively reported on the experiments of 10 August as follows:[7]

"WIRELESS TELEGRAPHY. EXHIBITION AT THE GENERAL POST-OFFICE. MORSE SIGNALS ON TAPE. Yesterday, at the top of the General Post-office building, an exhibition of wireless telegraphy was given by Mr. P. B. Walker, chief electrician and engineer-in-chief of the Postal Department. Ten feet copper wires were run from the sending and receiving instruments respectively, at either end of the building, each wire as it branched out into space being bright and slightly curved — in fact, the two wires might be said to point at one another, the Hertzian waves passing through the air, as in Marconi's experiments. When the apparatus had been set in position, the following message was sent to Mr. Watkin Wynne, who was at the receiving end:— "Mr. Walker is glad to announce wireless telegraphy as accomplished." Mr. Walker operated the ordinary Morse key himself, and the arrangements were perfect enough to bring the signals out in ink on a tape. The apparatus used consisted principally of a large 12in. spark induction coil, capable of radiating through space electric waves of very high pressure, and of a receiver, called a "coherer." The entire success of the experiments depends upon the arrangement of the latter, which consists of a small glass tube about 2in. long, into which two small plugs of silver are tightly fitted and separated from one another by about one-thirtieth of an inch. The space between these plugs is filled with a mixture of very fine iron filings of nickel and silver. The action of the electric waves, as radiated by means of the induction coil, causes these filings to cohere, and there-by makes an electric contact between the two silver plugs. The latter were for the purpose of the experiment connected with an ordinary telegraph (Morse) recording apparatus, and during the exhibition responded to every impulse radiated by the transmitter. The latter was, of course, controlled by an ordinary Morse key, the arrangement being that long and short streams of electric waves were sent out just as dots and dashes are used in the ordinary everyday working of land and cable wires, although, of course, the speed of the key has necessarily to be curtailed. All the instruments used were manufactured by the Government electricians under Mr. Walker's direction, Mr. Nelson being entrusted with the operation. Two months were occupied in their construction, and experiments have been going on during the past three weeks. The Postmaster-General recently placed £150 on the Estimates in order to obtain the necessary Marconi instruments. The latter are expected to arrive in the colony in about a month or six weeks, and upon their arrival it is intended to carry out experiments similar to those effected in Europe, and especially with the object of ascertaining whether our atmospheric conditions in any way influence the working of the machines."

Nelson's knowledge of wireless telegraphy was well developed and reflected personal interest as much as professional necessity. In a well crafted article over his signature for Sydney's Daily Telegraph newspaper of 2 January 1901, he neatly summarised developments in the field of wireless telegraphy over the last decade in a manner which still reads well today.[8] The overview provided gives appropriate credit to Marconi's advances while noting advances by other experimenters in the field. This position aligns closely with that of postal officials in Great Britain and Australia, already wary of possible monopolization of the technology by Marconi.