336 BELL SYSTEM TECHNICAL JOURNAL 



to his students, who had begun to gather round him in somewhat large 

 numbers, some of them coming from great distances; and to his family 

 he was a loving husband and father." 



It can be said in retrospect that the fundamental invention in radio- 

 telegraphy was made by Hertz, and yet it is true that the discoverer 

 of electric waves had no anticipations as to their utilitarian possi- 

 bilities. There was no rush to the patent office; indeed, it was not until 

 two years after Hertz's death that the first application for a radio 

 patent was filed, by Marconi. The chief interest at the time was purely 

 scientific, the results being hailed as the settlement of a great scientific 

 controversy, the confirmation of Maxwell's theory, the annexation to 

 electricity of the entire domain of light and radiant heat. In the cur- 

 rent literature we find little of prophecy with respect to utility. Sir 

 William Crookes has been credited with being one of the first to foresee 

 distinctly the applicability of "Hertzian" waves to practical teleg- 

 raphy. In an article in the Fortnightly Review for February, 1892, he 

 made a remarkably accurate forecast of what was to come: "simpler 

 and more certain means of generating electrical rays of any desired 

 wave-length"; "more delicate receivers which will respond to wave- 

 lengths between certain defined limits and be silent to all others"; 

 "means of darting the sheaf of rays in any desired direction. . . ." 

 And for secrecy he foresaw that "the rays could be concentrated with 

 more or less exactness on the receiver," if the sender and receiver were 

 stationary; or, if moving about, "the correspondents must attune their 

 instruments to a definite wave-length. . . ." "This is no mere dream 

 of a visionary philosopher," he wrote. "All the requisites needed to 

 bring it within the grasp of daily life are well within the possibilities of 

 discovery, and are so reasonable and so clearly in the path of researches 

 which are now being actively prosecuted in every capital of Europe that 

 we may any day expect to hear that they have emerged from the realms 

 of speculation into those of sober fact." 



As we well know, all that he predicted, and more, has become reality, 

 although progress was not to be as rapid as then seemed probable. 

 One of those who at the time had the imagination to see, if only hazily 

 perhaps, the great possibilities of Hertz's discovery was the youthful 

 Marconi, who had also the initiative and the determination to put his 

 ideas into execution, to make the new-found waves useful to mankind. 

 Within a few years, around the turn of the new century, the world was 

 to be thrilled by the detection of a wireless signal transmitted across 

 the wide Atlantic. But there were insurmountable limitations to the 

 means at hand, and it remained for still another wave in the onward roll 

 of science, the advent of the magical era of electronics, to yield the 



