THE ELECTRIC LIGHT 467 



proposed constructor, and to talk the matter over with. 

 him. The study of the inventor's mind which this habit 

 opened out was always of the highest interest to me. I 

 particularly well remember the impression made upon me 

 on such occasions by the late Mr. Darker, a philosophical 

 instrument maker in Lambeth. This man's life was a 

 struggle, and the reason of it was not far to seek. No 

 matter how commercially lucrative the work upon which 

 he was engaged might be, he would instantly turn aside 

 from it to seize and realize the ideas of a scientific man. 

 He had an inventor's power, and an inventor's delight in 

 its exercise. The late Mr. Becker possessed the same 

 power in a very considerable degree. On the Continent, 

 Froment, Breguet, Sauerwald, and others might be men- 

 tioned as eminent instances of ability of this kind. Such 

 minds resemble a liquid on the point of crystallization. 

 Stirred by a hint, crystals of constructive thought imme- 

 diately shoot through them. That Mr. Edison possesses 

 this intuitive power in no common measure is proved by 

 what he has already accomplished. He has the penetra- 

 tion to seize the relationship of facts and principles, and 

 the art to reduce them to novel and concrete combina- 

 tions. Hence, though he has thus far accomplished noth- 

 ing that we can recognize as new in relation to the elec- 

 tric light, an adverse opinion as to his ability to solve the 

 complicated problem on which he is engaged would be 

 unwarranted. 



I will endeavor to illustrate in a simple manner Mr. 

 Edison's alleged mode of electric illumination, taking ad- 

 vantage of what Ohm has taught us regarding the laws of 

 the current, and what Joule has taught us regarding the 

 relation of resistance to the development of light and 



