Lewis Howard Latimer

“ In the practical machine used in electric lighting, the core of the armature is made of thin discs of soft sheet iron; these discs are prevented from touching the shaft by the interposition of insulating material, and have insulating material, arranged between them so as to prevent their touching each other, they are however so rigidly secured to the shaft as to be in no danger of becoming loose when the shaft is rapidly rotated. Fig. 5 shows a complete armature, with commutator attached ready to be placed in position in the generator. ”

“ Millions of capital are being invested in its production, and it is being introduced throughout the world as rapidly as human activity, supplemented by all the agencies of an advanced civilization, can accomplish this end. ”

“ If the shaft which supports the loop is rapidly revolved; a current of electricity will be set up in the wire loop by bridging over the space at the ends of the wire between the metal plates with a piece of metal or another loop of copper wire; copper always being used to conduct electricity where it can be, for the reason that it is the best practical conductor of electricity. ”

“ In the first place we must have a large number of these wire loops, and as the wire is soft and easily bent, we must wind it about a core so as to hold it rigidly in place, as it has to be revolved very rapidly. Again, the ends of each wire loop must be brought out and attached to plates or blocks of metal, arranged upon some kind of non-conducting substance at one end of the shaft upon which the whole will turn. ”

“ Should you hold a horseshoe-magnet a slight distance above a long bar of iron, and then move it forward parallel thereto, you would find that it offered resistance to being moved thus, and that you would be forced to put forth some strength, both to keep it in motion as well as to prevent it being drawn down into contact with the iron ”

“ Electric Lighting by Incandescence, had barely got beyond the stage of a laboratory experiment, and the possibility of lighting large districts from a central station, as successfully as with gas, was doubted by men who now stand high in electrical circles. ”

“ As the current is generated, it flows toward the pieces of metal arranged on the end of the shaft, and from them into what are called brushes, which are flat pieces of metal that rest against those arranged on the end of the shaft so as to have intimate contact with them without retarding their rotation. ”

“ While these central stations cheapen the production of the light, and bring it within the reach of those who otherwise could not afford it, it does away with the large number of isolated plants, which formerly afforded the curious an opportunity to inspect the generation, distribution and utilization in light, of this form of energy. ”

“ Such a device as this would be of little service in producing the large currents needed for the electric light, both because there would be an insufficient amount of wire and, further, because such magnets as have been described—called permanent magnets—cannot be made sufficiently strong for the commercial generation of great currents. ”