Page:Incandescent electric lighting- A practical description of the Edison system.djvu/16

 without entering deeply into their intricacies.

We are all familiar with the common horse-shoe magnet, and have used it as a toy, if not otherwise.

While watching how readily a needle, tack, or other small object of iron or steel, would follow its movements, we have wondered how this motion was produced without the objects coming into actual contact with the magnet, and have rested content with the explanation that the phenomena before us, was the result of a force called magnetism, which resided in the magnet.

This force which stretched forth its invisible fingers to move the tiny needle, is that upon which depends the action of the electric generator; the magnet however, differing in size, and also in the method by which its magnetic powers are excited, as will be explained hereafter. For the present let us confine ourselves to the horse-shoe magnet with which we are so familiar.

If we take such a magnet, and wave it