Лим Ворд - New research on the kitchen table. Try this again стр 7.

And again the bands

We all know the long experience, usually conducted in physics lessons. A permanent magnet is placed under a solid sheet of paper. Iron sawdust is poured from above, and the cardboard is shaken slightly. In a brief moment of the state of weightlessness, jumping sawdust gets rid of frictional forces, and get the opportunity to settle on the lines of force of the magnet.