Page:On the various forces of nature and their relations to each other.djvu/174

170 of electricity pass through the wires which are round this iron for the purpose of shewing you what powerful effects we get. Here are the poles of the magnet; and let us place on one of them this long bar of iron. You see, as soon as contact is made, how it rises in position (fig. 54); and if I take such a piece as this cylinder, and place it on, woe be to me if I get my finger between: I can roll it over, but if I try to pull it off, I might lift up the whole magnet; but I have no power to overcome the magnetic power which is here evident. I might give you an infinity of illustrations of this high magnetic power. There is that long bar of iron