A compass is an instrument that has a pair of articulated arms, which are linked together by an axis or a hinge in its upper sector. With a compass it is possible to record distances and draw arcs or circles.
The compass usually has a point at the end of one of its arms and a pencil at the end of the other arm. In this way, the user sticks the tip on the paper and then separates both arms according to the radius of the circumference that he intends to trace. Finally, with one movement, he moves the pencil over the paper to draw the circle with the desired characteristics.
The flat compass is a device in which four geometric instruments are merged into one: the ruler, the square, the protractor and the compass described in the previous paragraph. Thanks to its versatility, it is not necessary to switch from one to the other when we want to draw geometric figures on a sheet or a blackboard. Its invention is attributed to a teacher from Mexico named Carlos Ricardo Hernández Ortiz, who presented it in 2007 to make up for the lack of materials in some schools in his land.
The notion of time signature is also used in the field of music to refer to the cadence or rhythm of a composition. The compass can be understood as an entity formed by various figures that are distributed in sets, opposing the unstressed parts and the accentuated parts.
The sign that establishes the links of value between the sounds, or that fixes the rhythm of the composition, is called the measure. The same happens with the movement that is carried out with the hand to mark, precisely, each measure. The term, on the other hand, refers to the space of the staff delimited with vertical lines where the various notes of a measure are written.
According to the amount of time, it is possible to differentiate between binary compasses, the ternary compasses and Quaternary bars. In addition, according to other subdivisions that are usually established, we can speak of simple bars or compound bars.
The compass is also one of the symbols of Freemasonry, along with the letter G and the square. The Masonic symbolism is the study of the Freemasonic symbols to find their meanings and understand the messages they represent, which are based mainly on the instruments used by the former French masons. It is believed that the expressions of Freemasonry can only be fully understood by the Freemasons themselves, and their symbols can be decoded by two systems, which increases their complexity.
The compass of proportions, also called a pantometer, is an instrument used to calculate or solve various problems in an indirect way. It is an analog calculator that relies on the proportionality between segments. It first appeared in 1555 in France, according to a patent in the name of Abel Foullon, who called it a “holometer.” However, it became popular thanks to the Italian philosopher Galileo Galilei.
Compass is also the common name for a navigational instrument that allows you to determine the direction of a ship (in other words, it is a compass). The reference point is always north, and in this way it is possible to calculate the angle of deviation with respect to this cardinal point and thus deduce the position on a map, combining this data with others.
Given the technological advances since the appearance of the first compass, there are currently several types, such as magnetic, gyroscopic and electronic, each of which performs calculations differently, in addition to offering advantages and disadvantages with respect to the others.