Compass universally used as compass until the invention of the box-like compass with a 'dry' pivoting needle sometime around 1300. Originally, many compasses were marked only as to the direction of magnetic north, or to the four cardinal points (north, south, east, west). Later, these were divided, in China into 24, and in Europe into 32 equally spaced points around the compass card. For a table of the thirty-two points, see compass points. In the modern era, the 360-degree system took hold. This system is still in use today for civilian navigators. The degree system spaces 360 equidistant points located clockwise
Geological compass iPhone using vector algebra. The accelerometers record vibration, so the iPhone needs be held still. Since very many measurements can be made in a few seconds, statistical analysis can be applied. High variance implies scattered data, so measurement should be continued until error diminishes to an acceptable level. It is important to consider such aspects in using a geological compass, for traditional compasses rely on inertia to remove error caused by operator movement. With traditional compasses there is no record of error caused by poor damping or operator movement. This limitation is removed by use of a digital compass, though