722 SKETCH OF HETNEICH HERTZ. 



bodies, would have to be looked upon as tbe conductor of electric 

 motion and power. Consequently tlie periodical motions of ether, which 

 our eye conceives as light, and which he figured as transversal waves, 

 were considered by Maxwell to be at the same time undulations of 

 electricity. These concei)tions, unproved by experiment as JVlaxwell 

 left them, had merely the value of a scientific hypothesis emanating 

 from a man of rare genius. To liave proved them facts, and tliereby 

 to have united two vast and highly important domains of natural phi- 

 losoj)Iiy, is the lasting credit of Professor Hertz. 



The complexity of phenomena of light and electricity and the insuffi- 

 cient opportunities afforded by the laboratory for deductions of such 

 magnitude rendered the obstacles barring the road to exact observation 

 well-nigh insurmountable. Many of the best and ablest naturalists 

 were laboring to cope with these difficulties. Two English scientists of 

 highest staiuling, Prof.G. F. Fitzgerald and Dr.O. T. Lodge, were during 

 the eighties occupied with experiments for the investigation and meas- 

 urement of electric waves. But it was reserved for Hertz to discover 

 and apply with marvelous ingenuity the necessary "detector," a reso- 

 nating circuit with an air gap, the resistance of which is broken down 

 by well-timed impulses, so that visible sparks are i^roduced. After an 

 unceasing course of experiments, in which he manifested indefatigable 

 energy and a wonderful faculty of reaching the very essence of the 

 matter, he succeeded in deciding the questions : Is the propagation of 

 electrical and magnetic forces instantaneous? and further. Can elec- 

 trical or magnetic effects be obtained directly from light"? The jjaper 

 "On very rapid electric oscillations," which was published in 1887, was 

 the first of a splendid series of researches which appeared in Wiede- 

 mann's Annalen between the years 1887 and 1890, and in which Hertz 

 showed with ample experimental i)roof and illustration that electro- 

 magnetic actions are propagated with finite velocity through space. 

 These twelve epoch-making j)apers were afterwards republished — with 

 an introductory chapter of singular interest and value, and a reprint of 

 some observations on electric discharges made by Von Bezold in 1870 — 

 under the title Uutersuchungen iiber die Ausbreitung der elektrischen 

 Kraft. A translation of this book, entitled Electric Waves, by D. E. 

 Jones, B. Sc, with illustrations and a preface by Lord Kelvin, has just 

 been published in England. 



In 1889, when laying before the Congress of German Naturalists at 

 Heidelberg the results of his labors, Professor Hertz, with the modesty 

 characteristic of the true investigator, the utterly unassuming disciple 

 of science, gave ready and graceful acknowledgment to the efforts made 

 by his predecessors or cooperators in the work, some of whom had all 

 but attained the results which they aimed at and which he achieved. 

 It is pleasant to recollect that when he had gained the end toward 

 which they also had been striving, the English professors, Oliver Lodge 

 and Fitzgerald, were foremost in announcing his success, and in prepar- 



