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
Straightedge and compass construction these straightedge and compass constructions have been shown to be logically impossible to perform. (The problems themselves, however, are solvable, and the Greeks knew how to solve them, "without" the constraint of working only with straightedge and compass.) The most famous of these problems, squaring the circle, otherwise known as the quadrature of the circle, involves constructing a square with the same area as a given circle using only straightedge and compass. Squaring the circle has been proven impossible, as it involves generating a transcendental number, that is, . Only certain algebraic numbers can be constructed with ruler and compass