... lines and horseshoe magnetic induction lines respectively by exchanging the riser and the permanent-magnet. The machine is connected by inserting ... Induction Line Demonstrator 1, Bar Magnet, 2, Bracket Plate, 3,Riser, 4, Horseshoe MagnetTheoryWhen you put a permanent magnet into the ... 3 Put the horseshoe magnet into the groove of raised riser, install the five pieces of small risers and buckle ...