Compass

Abstract

No matter where a person stands on planet earth, one can hold a compass in his or her hand, and it points to north. What an amazing item! Imagine if one is in the center of the ocean or sea, and when one looks around and in all direction and all they see is water, and it is a cloudy one cannot see the sun.  How would that person know his or her way out unless they have a compass to direct them?  Long before the innovation of GPS satellites and other aids of high-tech navigation, people used compass as the easy and less expensive way to orient themselves (Bjo and Carina Pg 58).  So, what makes the compass function in the way it does? And why is it important to detect small magnet fields? In this paper, we will discuss the history of the Compass and the types of compass that are available.

Introduction

A compass is a very simple item. A compass comprises of a small, featherweight balanced on a frictionless pivot point.  The compass is normally known as needle. On one end of the needle, it normally marked “N” which stands for north or gets colored in a certain way to show that it points at the north side.  On the surface that is what a compass is comprised of (Aczel, Amir Pg 79).

The manner in which the magnet works is more amazing. It turns out that one can think of planet earth having a huge magnet which gets buried inside.  So as the north end of the compass point to the north side, one has to presume that the huge bar magnet points the south end. Hence, if one thinks of the world in this manner, one can see that the ordinary rule of magnet that is “opposites attracts”, would make the north end of the compass needle point at the south end of the magnet bar that gets buried. Hence, the compass normally points towards North Pole (Aczel, Amir Pg 96).

For the bar magnet to be fully accurate, it does not operate on the rotational axis of the earth. It gets tilted to some extent off the center. This tilting is referred to as declination, and several reliable maps show what the declination is in various parts- this is because it changes a little considering where one is on the planet.  On the exterior, the earth’s magnetic field is fairly weak. Furthermore, the earth is around 8000 miles. Hence, the magnetic field ha to go a long way to making an impact on the compass. This is the reason the compass is required to have a frictionless bearing and a lightweight magnet (Kling and John pg 57).  Otherwise, there will be no sufficient power in the magnetic field of the earth to make the needle turn.

The big bar magnet that is buried in the main analogy functions to offer an explanation as to why the planet earth has a magnet filed. Nevertheless, that is not what is happening. Nobody is aware, but there s a theory that people have. As discussed above, the core of the earth is thought to comprise hugely of a molten iron. However at that core, the pressure is huge that the super hot iron crystallizes into becoming solid.  Conception that the heat radiating from the core together with the earth rotation causes the liquid iron to move in a rotational manner. It is thought that these forces of rotation in the layer of the liquid iron results in weak forces of magnetic around the axis of turn.  It turns out that since the magnetic field of the ear is very weak; a compass is used as a detector for the magnet fields formed by anything.  That is the reason people can use the compass in detecting the small magnetic field which gets produced by a wire carrying a current (Coleman pg 39).

History of Compass

According to Deng and Pingxing (pg 108) China is where the first compass got invented. It got invented during Dynasty of Han in the 1st century AD and 2nd century BC and it got created so as to assist with the practice of Feng Shui. The practice entailed aligning one and others with the planet earth.  The people of ancient China used the compass in directing them to the life of oneness and balance with the earth. During the Song Dynasty, t was used in navigation of military by 1044 to 1044 and navigation of maritime by 1111 to 1117. In the 1300s in medieval Europe, the dry compass got developed and in the early 20th century, there was an invention of liquid-filled magnetic compass. The modern compass that is still used today got invented by William Sturgeon.  After discovering that compass, William got put into a compass, and the people involved with the formation discovered the strength that the compass contained.  Without the discovery of William, the modern compass would not contain its main component.  Compass was initially formed when loadstones, a mineral that in nature magnetized the ore of iron got suspended from the board with the capability to turn and pivot. It got discovered that the stones often pointed in the same direction and lined up themselves to the south or north axis of the planet earth.

Around the turn of 14th century, the first magnetic compass appeared in Europe at Amalfi. However, it has never been established if the magnetic compass got invented in the west or it moved to Europe together with trade routes that came from China.  Nevertheless, it is vivid that since military advantage and sea trade were of more strategic significance to western countries, they moved the magnetic compass technology far deeply than the Chinese did (Deng and Pingxing pg 79). With the rise of Spanish, English, Dutch and Portuguese empire, the growth of the compass moved to the European countries that face Atlantic Ocean.

The biggest challenge that the compass raised is what today people refer to as magnetic variation: the angular variation between geographic or “right” magnetic north and north, or the where the magnetized needle face. Under vivid skies, a person could locate the geographic north-south axis for comparing with where the compass faced by viewing the sun at noon or by referring to the polestar (Kling and John pg 43).  From the corner to corner of the Mediterranean the diversity between the magnetic north and geographic north was not big. Nevertheless, in the Atlantic, especially in the northern latitudes, the diversity was substantial.  If the diversity had been stable, there would be no hitch; however it varied hugely as a person moved east to west. In the year 1492, during the Christopher Columbus  first  voyage to North America from Spain, he observed this strange behavior, but he hide it from his crew since he feared it would spook them.

Compass Rose

The rose of compass is a representation of direction and orientation that get placed on charts, maps, and compasses. Thirty-two points get portrayed around a circle in intervals that are equal marking the four main cardinal directions (N, E, S, W), the sixteen secondary intercardinal and the other four intercardinal directions (NW, SE, NE, SW). The 32 points got drawn to show winds, and the sailors used them in direction-finding.  The 32 points stood for the eight main winds, the 16 quarter winds, and the half-winds. On the early roses of compass, the eight main compass could get seen with a letter abbreviation above the line which marked its name, as today we do with the N (north), S (South), E (east), and W(west). Afterwards the compass rose, during the time of Christopher Columbus, and the exploration of Portuguese, depicts a fleur-de-lys which replaced the first letter T which stood for (Tramontana, the north wind name) that marked north. And replaced the first letter L (which stood for levanter), which marked east, depicting the Holy Land direction (Bjo and Carina Pg 125). Today, people still see cross symbols and fleur-de-lys on roses of compass, if not the initial letters for the directions of the cardinal. Each cartographer devises a compass rose differently, by use of different symbols, colors, and graphics. Several colors get used as means of distinguishing the numerous lines and points on a compass rose easily.

360 Degrees

Most current compasses use the systems of 360-degree of showing direction on the compass with 0 and 360 degrees symbolizing north,180 degrees standing for South, 90 degrees standing for east, and 270 degrees standing for West. Through the utilization of degrees, navigation is accurate than through utilization of compass rose.

There are different types of compasses used across the world, and they include

Magnetic compass

            This is the easiest and familiar types of compass; it gets aligned to the magnetic field of the earth. This compass faces the magnetic north pole of the earth (Northern Canada is where the magnetic north pole is located, but it moves continually, although slowly. A magnetic compass is simple and easy to build device, however it should be laid flat on a platform, needs some time to regulate to a changed platform, and may go through intrusion from local magnetic fields. So as to regulate a magnetic compass to face north and to face the geographic North Pole, one should be aware of the amount of magnetic variation or declination that is there in a particular area.  There are online calculators and maps available that offer the declination difference between magnetic north and true north for each point on the world (Aczel, Amir Pg 142).  By regulating a person’s magnetic compass based on the local magnetic declination, there is a possibility of ensuring a person’s direction is exact.

The Gyroscopic compass

This type of compass gets lined up to the true North Pole, and it has a needle that turns in connection with earth rotation. They are usually used by aircrafts and ships to avoid any interference with navigation by any local magnetic device. Hence, they can easily and quickly adjust to the movements. This kind of compass is often set to point to true north, on the basis of the direction of a magnetic compass, and then checked from time to time with a magnetic compass so as to ensure its accuracy.

Uses of a compass

Several people use the compass casually, for example with camping or hiking. In such circumstances, a basic compass like the thumb compass or any other orienting compass that is clear and can get read via the map is appropriate (Trumbauer Pg 18).  Several casual utilization where travel is of short distance there is a need for basic markings for the directions of the cardinal and basic knowledge of compass. For navigation that is advanced, whereby big distances get covered, and a small variation of degree would offset someone’s course, an intense knowledge of reading compass is needed. Knowledge declination, the angle that is between magnetic north and true north, the marking of 360 degrees on the face of the compass, and one’s course of direction arrow joined with person instructions of compass need a study that is advanced. In case one does not know where he or she is, but recognizes the features surrounding him or her on the map, the compass can get used to pinpoint one’s location through triangulation.

Conclusion

The compass got redeveloped and started to be utilized in the way that is usually used today. Compasses offer directions to travelers and individuals who travel by shy, land, or sea normally uses them. The compass is a tool for navigation, and it shows, for the travelers the direction they are heading to. The compass inner dial taps into magnetic frequencies from the planet earth and points towards the direction that the traveler is heading (Trumbauer pg 29)

Works cited

Aczel, Amir D. The Riddle of the Compass: The Invention That Changed the World. New York: Harcourt, 2001. Print.

Bjo,M. and Carina E. Be Expert with Map & Compass. 3rd ed. Hoboken, N.J.: Wiley, 2010. Print.

Coleman, J. The Compass. New York: Knopf :, 1990. Print.

Deng, Y. and Pingxing W. Ancient Chinese Inventions. Updated ed. Cambridge, UK: Cambridge UP, 2011. Print.

Kling, T. L. and John S. E. The Compass. New York: Perseus Group, 2010. Print.

Trumbauer, L. You Can Use a Compass. New York: Children’s, 2003. Print.