28 Mr. 0. J. Lodge. Experiments on [June 4, 



True that the Melde experiment does not measure the wave-length 

 in air, and so also the observation of Mr. Chattock and myself would 

 only measure the wave-length on wire ; but it had already been shown 

 by Mr. Heaviside among others, by Kirchoff also (though I did not 

 know of Kirchoff's work), that pulses travelled along insulated non- 

 magnetic wires at the same speed as waves through air, or at a speed 

 only insignificantly less. In fact Mr. Poynting has taught us to 

 regard all these effects as conveyed through the air, i.e., by the ethereal 

 medium, in a manner only very subordinately affected by the material 

 of the conductor. 



Hence the waves guided by long isolated wires and measured in 

 recoil kick experiments ought to be the same length as, or only 

 slightly shorter than, the true ether-waves spreading out from the 

 oscillating circuit into space. 



The fact that electric waves could be thus detected and measured, 

 I stated at the Society of Arts, on March 17, 1888, and published 

 more precisely in the ' Phil. Mag.' for August, 1888 ; but to this 

 latter I appended a footnote to say that in the current number of 

 Wiedemann's ' Annalen,' viz., that for July, the same year, there 

 was a paper by Dr. Hertz, describing some experiments he had made 

 at Karlsruhe, whereby he had detected the waves in free space : a 

 research which in the following September was enthusiastically pro- 

 claimed to the world by Fitzgerald, at Bath. At the same meeting I 

 described in general terms my detection of the waves on the surface 

 of conducting wires. It appears that Hertz began, much as I had 

 done, by the observation of surging circuits ; for, using a coil instead 

 of an inductive machine, and attaching to one terminal a nearly 

 closed rectangle, he observed it spark across the gap. In this obser- 

 vation also he had the start of me, for his first paper appeared in 

 1887 ; and in his rapid development of it, in the comparative freedom 

 from students of Karlsruhe, he struck on the influence between one 

 circuit and another across space, and so made the astonishing dis- 

 covery that the radiation in air was intense enough to cause sparks 

 in conductors upon which it fell. 



This same discovery would have been made by the audience at the 

 Royal Institution on the evening of March 8, 1889, if it had not 

 been made before ; for, during a lecture on Leyden jars, every time 

 one was discharged through a considerable length of wire, the heavily 

 gilt wall paper sparkled brightly, by reason of the incident radia- 

 tion. 



The achievement of Hertz is well known, and it is only the 

 customary interest attaching to circumstances connected with what 

 will probably be regarded as an epoch in electrical science that con- 

 stitutes my excuse for making the above statement. 



One point, about which there has been some controversy, my expe- 



