Magnetic Needle. A small bar of iron, to which, by artificial means, the peculiar arrangement of the magnet has been transferred, by which it points in the magnetic meridian; and, the direction of this meridian being known, the course of ships at sea is thereby determined. It also dips or inclines from the plane of the horizon, pointing in the northern hemisphere downward at the North Pole of the magnet, and in the Southern hemisphere contrarily.