HUGHES DISCOURAGED. 117 his experiments on aerial transmission. The experiments shown were very successful, and at first they seemed astonished at the results; but toward the close of three hours' experiments Professor Stokes said that all the results could be explained by known electromagnetic induction effects," and therefore he could not accept my view of actual aerial electric waves unknown up to that time, but thought I had quite enough original matter to form a paper on the subject to be read at the Royal Society. "I was so discouraged," he continues, "at being unable to convince them of the truth of these aerial electric waves that I actually refused to write a paper on the subject until I was better prepared to demonstrate the existence of these waves; and I continued my experiments for some years, in hopes of arriving at a perfect scientific demonstration of aerial electric waves produced by a spark from the extra currents in coils, or from frictional electricity, or from secondary coils." Thus, it would appear that, through the discouragement of three scientific men, an Englishman was robbed of the honor of being the first to announce the discovery of wireless telegraphy. Howbeit, the distinction remains his, as has been generally recognized, not only by his own countrymen, but by foreign scientists as well. transmitter and receiver were in different rooms, about sixty feet apart. "After trying successfully all distances allowed in my residence in Portland Street," Hughes proceeds, "my usual method was to put the transmitter in operation and walk up and down Great Portland Street with the receiver in my hand, with the telephone to the ear. The sounds seemed slightly to increase for a distance of sixty yards, then gradually diminish, until at 500 yards I could no longer with certainty hear the transmitted signals. What struck me as remarkable was that opposite certain houses I could hear better, while at others the signals could hardly be perceived. Hertz's discovery of nodal points in reflected waves (in 1887-'89) has explained to me what was then considered a mystery. At Mr. A. Stroh's telegraph instrument manufactory, Mr. Stroh and myself could hear perfectly the currents transmitted from the third story to the basement, but I could not detect clear signals at my residence about a mile distant. The innumerable gas and water-pipes intervening seemed to absorb or weaken too much the feeble transmitted extra current from a small coil." On February 20, 1880, Mr. Spottiswoode, the President of the Royal Society, together with Professors Huxley and G. Stokes, the honorary secretaries, called upon Professor Hughes to see HUGHES DISCOURAGED. 117 his experiments on aerial transmission. The experiments shown were very successful, and at first they seemed astonished at the results; but toward the close of three hours' experiments Professor Stokes said that all the results could be explained by known electromagnetic induction effects," and therefore he could not accept my view of actual aerial electric waves unknown up to that time, but thought I had quite enough original matter to form a paper on the subject to be read at the Royal Society. 66 "I was so discouraged," he continues, at being unable to convince them of the truth of these aerial electric waves that I actually refused to write a paper on the subject until I was better prepared to demonstrate the existence of these waves; and I continued my experiments for some years, in hopes of arriving at a perfect scientific demonstration of aerial electric waves produced by a spark from the extra currents in coils, or from frictional electricity, or from secondary coils." Thus, it would appear that, through the discouragement of three scientific men, an Englishman was robbed of the honor of being the first to announce the discovery of wireless telegraphy. Howbeit, the distinction remains his, as has been generally recognized, not only by his own countrymen, but by foreign scientists as well. CHAPTER VIII The imperfect means at Hertz's command-The coherer and its history-Guitard-Varley-Onesti-Professor Branly-His radioconductor-Sir Oliver Lodge and the coherer-His experiment at Oxford in 1894— Rutherford-Dr. Muirhead-Captain Jackson-Professor Bose-Professor Righi-Lodge's new coherer -Popoff's experiments. 66 THE attainment of a "perfect scientific demonstration of the existence of aerial electric waves," for which Hughes continued to work, but unfortunately failed to achieve, proved to be an almost easy conquest to the genius of Hertz, whose strenuous and favored youth (as Sir Oliver Lodge puts it) was surrounded with all the influences that go to make an accomplished man of science." Truth, however, demands that full recognition should be accorded to others whose discoveries and inventions helped forward the final achievement which was the outcome of his labors. With the imperfect means which Hertz had at his command he would probably have held it impossible to obtain visible effects or to transmit signals by means of electric waves that would be audible at any but a very short distance from their place of origin; and yet the dis FIRST HINT OF COHESION. 119 coverer of the microphone had already actually obtained such results. 66 This could not have been done without the discovery of those wonderful instruments which are now so well known to the scientific world as sensitive contacts," coherers," or radioconductors." Space forbids us to go very deeply into the history of these various contrivances, so essential to wireless telegraphy; but some little account of them is necessary to make the story we are telling complete. The principle of the coherer, or the radioconductor, lies in the sensitiveness of metal filings enclosed in an insulating tube to electric currents of low potential. Sir Oliver Lodge tells us that probably the earliest discovery of cohesion under electric influence was contained in an observation of Guitard in 1850, that when dusty air was electrified from a point the dust particles tended to cohere into. strings or flakes.* Mr. S. A. Varley made a practical application of the same principle in the construction of his lightning protector for telegraph apparatus, which he told the British Association in 1870 had been in use several years. It consisted of two thick metal conductors terminating in points, the chamber containing the points being loosely filled with a powder consisting of carbon and a non-conducting substance in a minute state of division. "The lighting finds in its * Signaling through Space without Wires. |