Page:Incandescent electric lighting- A practical description of the Edison system.djvu/18

 these conditions would remain practically the same were the magnet bent in horse* shoe form.

If we substitute for the needle a loop of copper wire we shall, by the motion before described, induce in the copper wire a current of electricity, and that without actual contact between the magnet and the wire.

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; in fact, the sensation would be much the same as that experienced in moving a brush across the surface of a liquid, oil for instance, with the bristles just touching its surface.

These invisible bristle-like projections produce the current of electricity in the wire when the latter cuts through them.