Simple phenomena of magnetism — Describe

How can you plot the magnetic field pattern of a magnet using iron filings or a compass?

Iron filings method: place a sheet of paper over the magnet, sprinkle iron filings evenly on top and tap gently - the filings line up along the field lines, revealing the pattern. Plotting compass method: place a small compass near the magnet, mark the position of each end of the needle with a dot, move the compass so its tail sits on the previous dot and mark the new position, repeating this to trace out a full field line; joining the dots shows a line, and the compass needle's N pole always points in the local field direction (from the magnet's N pole towards its S pole).