The Strafford Evening Post WITH WHICH IS INCORPORATED THE EGMONT SETTLER. WEDNESDAY, AUGUST 15, 1923. WIRELESS TELEGRAPHY.

Stratford Evening Post, Volume XXXIX, Issue 85, 15 August 1923, Page 4

The Strafford Evening Post WITH WHICH IS INCORPORATED THE EGMONT SETTLER. WEDNESDAY, AUGUST 15, 1923. WIRELESS TELEGRAPHY.

Those who have watched the progress of wireless telegraphy dur.ng the past twenty-five years will be gratified to note that a festival in honor of Professor Brauley has been' celebrated in Paris. In 1890 Professor Branley discovered that a pinch of certain metallic filings, loosely contained in a glass tube, did not, under normal conditions, allow an electric current to pass. If, however, an electric spark were produced, even at a distance, the filings immediately permitted the passage of a current and remained in this conducting condition until a slight mechanical jar restored, them to the former state. This experiment, made purely in the course of research work, provided the inspiration which has led to the present development of the science. The discovery attracted no attention until described by Dr. Dawson Turner at the British Association in 1892, but even then the possibilities were not appreciated, although durng the following year a few physicists realised that the action discovered by Branley was due to waves emitted by the spark. Thus the phenomenon remained of academic intcest only until 1894, when Marconi, who was not yet 21, began serious investigations of the possible arpl'cntion of the discovery to signalling without wires, and in Ip c, r than a year succeeded in transmitting signals over a distance of a quarter of a mile. It is interesting to note that his aerials consisted of two tins,

the size and shape of biscuit boxes, each mounted on a pole about 25ft high. In. his hands the "coherer," as Branley's tube was called, underwent rapid improvement, and means were invented of observing and recording the signals received. Two years later Marconi went to England, and, fortunately, secured the enthusiastic assistance of Sir "William Prrece, then engineer-in-chief to the Post Office, who was experimenting wi h a system of his own, but which he abandoned after seeing that of Marconi. Successful experiments were carried out on Salisbury Plain, using an ordinary spark coil and the improved Branlcy tube, and it then became possible to visualise in some measure the future possibilities of the new science Concluding the lecture, which he delivered on the subject at the Royal Institution in 1897. Sir William Preece said: "He (Marconi) has not discovered any new rays; his receiver is based on Bronley's coherer. Columbus did not invent th© egg, but he showed how to make it stand on its end. Marconi has produced from known means a new electric instrument, and a new electric eye. more •deHcate than any known electric Instrument, and a new system that will reach places hitherto inaccessible." It is only natural, therefore, that the first message transmitted across the Channel by Marconi should have been addressed to Professor Branley.