SCIENTIFIC PROBLEMS IN 

 RADIOTELEGRAPHY 



By J. A. FLEMING, M.A., D.Sc, F.R.S. 



The scientific questions that must be considered when any 

 branch of experimental work is carried beyond a laboratory 

 stage into the larger field of technical application are often 

 very interesting and instructive. Apart altogether from the 

 difficulties of conducting them on an enlarged scale or any 

 questions of utility or profit, entirely new problems are often 

 brought into view when we magnify the range or extent of 

 our operations. This is true particularly of the attempts made 

 to apply our knowledge of electromagnetic waves to long 

 distance wireless telegraphy. 



After Hertz had shown us experimentally how to produce 

 Maxwell's electromagnetic waves and at one stroke given life to 

 the dry bones of certain mathematical equations familiar enough 

 to students of Maxwell's great treatise but otherwise " caviare 

 to the general," physicists all the world over entered with 

 unlimited delight upon the conquest of this new field of 

 research. Laboratory experiments on electromagnetic waves 

 became the order of the day but were carried on during five 

 years or more before the idea arose of utilising them for 

 telegraphic purposes. Sir William Crookes's remarkable fore- 

 cast in the Fortnightly Review in 1892 showed that the notion of 

 so using them had already been clearly formed ; moreover, had 

 the late Prof. D. E. Hughes not allowed himself to be dis- 

 couraged by criticism of some very original experiments he 

 showed to friends, radiotelegraphy might have been an established 

 fact before that date. 



There is a wide gulf, however, between prognostications or 

 suggestive experiments and a practical invention. The real 

 invention or discovery which made possible an advance from 

 laboratory experiments with Hertzian waves to electric wave 

 telegraphy in any proper sense of the word was not merely an 



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