A freely suspended magnet will align itself with the Earth's magnetic field (assuming no other fields influencing the magnet). The total field (force T) is resolved into a horizontal component (force H) and a vertical component (force Z). We try to keep the magnets in a direct reading compass as close as possible to the local horizontal by suspending them below the pivot point and, in some cases, by adding weights to bias them for the northern hemisphere or the southern hemisphere. The alignment of the horizontal component of the Earth's field is, therefore, the azimuthal alignment of magnetic North.