A compass is a device that indicates direction. It is one of the most important instruments for navigation. Magnetic compasses are the most well known type of compass. They have become so popular that the term “compass” almost always refers a magnetic compass. While the design and construction of this type of compass has changed significantly over the centuries, the concept of how it works has remained the same. Magnetic compasses consist of a magnetized needle that is allowed to rotate so it lines up with the Earth's magnetic field. The ends point to what are known as magnetic north and magnetic south. Scientists and historians don’t know when the principles behind magnetic compasses were discovered. Ancient Greeks understood magnetism. As early as 2,000 years ago, Chinese scientists may have known that rubbing an iron bar (such as a needle) with a naturally occurring magnet, called a lodestone, would temporarily magnetize the needle so that it would point north and south. Very early compasses were made of a magnetized needle attached to a piece of wood or cork that floated freely in a dish of water. As the needle would settle, the marked end would point toward magnetic north.As engineers and scientists learned more about magnetism, the compass needle was mounted and placed in the middle of a card that showed the cardinal directions—north, south, east, and west. A spearhead and the letter T, which stood for the Latin name of the North Wind, Tramontana, signified north. This combination evolved into a fleur-de-lis design, which can still be seen today. All 32 points of direction were eventually added to the compass card. Historians think China may have been the first civilization to develop a magnetic compass that could be used for navigation. Chinese scientists may have developed navigational compasses as early as the 11th or 12th century. Western Europeans soon followed at the end of the 12th century. In their earliest use, compasses were likely used as backups for when the sun, stars, or other landmarks could not be seen. Eventually, as compasses became more reliable and more explorers understood how to read them, the devices became a critical navigational tool. Adjustments and Adaptations By the 15th century, explorers realized that the “north” indicated by a compass was not the same as Earth’s true geographic north. This discrepancy between magnetic north and true north is called variation (by mariners or pilots) or magnetic declination (by land navigators) and varies depending on location. Variation is not significant when using magnetic compasses near the Equator, but closer to the North and South Poles, the difference is much greater and can lead someone many kilometers off-course. Navigators must adjust their compass readings to account for variation. Other adaptations have been made to magnetic compasses over time, especially for their use in marine navigation. When ships evolved from being made of wood to being made of iron and steel, the magnetism of the ship affected compass readings. This difference is called deviation. Adjustments such as placing soft iron balls (called Kelvin spheres) and bar magnets (called Flinders bars) near the compass helped increase the accuracy of the readings. Deviation must also be taken into account on aircraft using compasses, due to the metal in the construction of an airplane. Magnetic compasses come in many forms. The most basic are portable compasses for use on casual hikes. Magnetic compasses can have additional features, such as magnifiers for use with maps, a prism or a mirror that allows you to see the landscape as you follow the compass reading, or markings in Braille for the visually impaired. The most complicated compasses are complex devices on ships or planes that can calculate and adjust for motion, variation, and deviation. Other Types of Compasses Some compasses do not use Earth’s magnetism to indicate direction. The gyrocompass, invented in the early 20th century, uses a spinning gyroscope to follow Earth’s axis of rotation to point to true north. Since magnetic north is not measured, variation is not an issue. Once the gyroscope begins spinning, motion will not disturb it. This type of compass is often used on ships and aircraft. A solar compass uses the sun as a navigational tool. The most common method is to use a compass card and the angle of the shadow of the sun to indicate direction.Even without a compass card, there are techniques that use the sun as a compass. One method is to make a shadow stick. A shadow stick is a stick placed upright in the ground. Pebbles placed around the stick, and a piece of string to track the shadow of the sun across the sky, help a navigator determine the directions of east and west.Another type of solar compass is an old-fashioned analog (not digital) watch. Using the watch’s hands and the position of the sun, it is possible to determine north or south. Simply hold the watch parallel to the ground (in your hand) and point the hour hand in the direction of the sun. Find the angle between the hour hand and the 12 o’clock mark. This is the north-south line. In the Southern Hemisphere, north will be the direction closer to the sun. In the Northern Hemisphere, north will be the direction further from the sun. Receivers from the global positioning system (GPS) have begun to take the place of compasses. A GPS receiver coordinates with satellites orbiting the Earth and monitoring stations on Earth to pinpoint the receiver's location. GPS receivers can plot latitude, longitude, and altitude on a map. Unless large objects block signals, readings are usually accurate to within about 15 meters (50 feet). Despite advancements with GPS, the compass is still a valuable tool. Many airplanes and ships still use highly advanced compasses as navigational instruments. For casual observation—for navigators on foot or in a small boat—a pocket compass or a basic compass mounted on a dashboard remains a practical and portable tool.
Fast Fact
Animals and CompassesMany animals—such as certain types of ants, fish, and birds—use the sun as a compass to help them find direction. They use their internal biological clock to compensate for the sun shifting in the sky and maintain a straight course. Other animals—like pigeons—are able to navigate using the Earth’s own magnetic field. Their brains function like an internal magnetic compass to follow the Earth’s magnetic field.
Fast Fact
Pole SwapIf you were using a compass 800,000 years ago and facing north, the needle would point to the south magnetic pole. Why? Even though the Earth acts like a giant magnet, it is not stable. Both the north and south magnetic poles are slowly shifting. Since the magnetic north pole was discovered in the early 19th century, it has drifted northward by more than 966 kilometers (600 miles) and it continues to move about 40 miles per year. The north and south magnetic poles have also switched places many times in the Earth’s history.
Fast Fact
Spiritual Orienteering
The Chinese first used compasses not for navigation, but for spiritual purposes. They used the magnetic devices to organize buildings and other things according to feng shui, the ancient practice of harmonizing an environment according to the "laws of Heaven."
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Ordnance Survey UK: How to Use a Compass
FAQs
How did the compass improve society? ›
Compasses made it possible for explorers to sail far out into oceans and away from land—no matter what the weather was like. This led to more exploration, the discovery of new countries, and trade with other cultures.
What is compass class 6th? ›A compass is an instrument which is used to find the direction of a magnetic field. A compass consists of a small metal needle which is magnetized and is free to turn in any direction. Therefore, in the presence of a magnetic field, the needle is able to line up in the same direction as the field.
What is a compass class 3? ›A compass is a tool for finding direction. A simple compass is a magnetic needle mounted on a pivot, or short pin. The needle, which can spin freely, always points north. The pivot is attached to a compass card.
What is the relevance of the compass to the scientific community? ›A compass can be used to calculate heading, used with a sextant to calculate latitude, and with a marine chronometer to calculate longitude. It thus provides a much improved navigational capability that has only been recently supplanted by modern devices such as the Global Positioning System (GPS).
How does a compass make life easier? ›Compass is an amazing tool to show north direction irrespective of any place you are in. The needle of the compass moves freely to the Earth's magnetic field.
What was the purpose of the compass? ›A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north.
What are the 3 uses of compass? ›Uses of a compass
A compass helps you to: Know which direction you are travelling in – this is called your heading. Align or orientate your map with your surroundings – setting the map.
8-wind compass rose
The four cardinal directions are north (N), east (E), south (S), west (W), at 90° angles on the compass rose. The four intercardinal (or ordinal) directions are formed by bisecting the above, giving: northeast (NE), southeast (SE), southwest (SW) and northwest (NW).
A compass is a device that indicates direction. It is one of the most important instruments for navigation.
What are the 4 points on a compass called? ›The four cardinal directions, or cardinal points, are the four main compass directions: north, east, south, and west, commonly denoted by their initials N, E, S, and W respectively.
How is compass made? ›
The needle in a compass is made of magnetised metal, usually iron, placed on a pivot or pin, and suspended in liquid (usually some kind of mineral oil or white spirit) so it can freely turn. The compass' needle can detect the magnetic field of the Earth and faces the Magnetic North, when held level in your hand.
What are the 4 compass points? ›North, east, south, and west are the four cardinal directions, often marked by the initials N, E, S, and W. East and west are at right angles to north and south. East is in the clockwise direction of rotation from north.
How does compass influence our lives today? ›Even though the compass was invented in Ancient China it has helped shaped the modern world in many ways. Today's compass is smaller, lighter weight, and more efficient than those from ancient times. We still use a compass to find our way on a trip or in a new place.
How did the compass impact the economy? ›The magnetic compass impacted economy because, in allowing the Europeans to reach the Americas and the Indian Ocean trade routes, trade increased and the prosperity of Europe grew. In the Colombian Exchange, the magnetic compass helped direct people to either the Americas, Europe or Africa.
How does a compass work simple explanation? ›A compass works by detecting and responding to the Earth's natural magnetic fields. The Earth has an iron core that is part liquid and part solid crystal, due to gravitational pressure. It is believed that movement in the liquid outer core is what produces the Earth's magnetic field.
How do you use a compass in real life? ›Pick up the compass and hold it flat in front of you. Be sure that the direction of travel arrow points straight ahead. Then, rotate yourself, keeping an eye on the magnetic needle. When the red end lines up exactly with the orienting arrow, stop.
What can affect compass? ›Objects to avoid include wristwatches, keys, tables with metal legs or steel screws, mobile telephones and even heavy framed spectacles. Many geological formations, and for that matter, many rocks, are magnetized and can affect compass readings, as can electricity power lines.
What affects compass accuracy? ›Like declination, local attraction will impact the compass. High voltage power lines, car bodies, and flashlight batteries will impact the compass too. To lessen the impact on a magnetic compass and improve its accuracy, do these 3 steps: use the most current declination data for an area.
Why is it called a compass? ›Etymology 1
From Middle English compas (“a circle, circuit, limit, form, a mathematical instrument”), from Old French compas, from Medieval Latin compassus (“a circle, a circuit”), from Latin com- (“together”) + passus (“a pace, step, later a pass, way, route”); see pass, pace.
Again the compass came to the rescue, giving Columbus the ability to find north and allowing him to keep consistent latitude without the use of heavenly bodies.
Who created the compass? ›
The first compass was probably invented by the Chinese sometime around the first century. While historians aren't sure of the exact origin of the compass, Chinese sailors had it about a thousand years before Europeans invented a version of the compass.
What is the compass on a map called? ›Compass Rose. The compass rose shows you directions on a map. Cardinal directions are north, south, east, and west.
What is the most important compass point? ›Useful things to know
There are four main points on your compass: north, south, east and west. Around the whole compass, there are little measurements, called degrees. The most important part on the compass is the magnetic needle.
The 16 Point Compass has green and yellow thermoplastic shapes with white formed thermoplastic lines indicating the direction of each arrow. This marking is 4.25 metres in diameter and is an excellent way to introduce children to geography.
How do you remember the 16 point compass? ›The mnemonic is “Never Eat Soggy Waffles.” The first letter of each word is the same as the cardinal direction that it represents. The order of the words mimics the order in which the cardinal directions appear on a compass: North, East, South, and West.
What is a compass question and answers? ›An instrument containing a magnetized pointer that shows the direction of magnetic north and bearings from it is called a compass. It's a device with magnetic needles used for showing the direction one is facing.
What is compass and example? ›plural compasses. Britannica Dictionary definition of COMPASS. 1. [count] : a device that is used to find direction by means of a needle that always points north. He always carries a compass when he walks in the woods.
How many types of compass are there? ›Two main types of the compass are magnetic compass and gyrocompass. First one has a magnetic element (needle or a card) that aligns itself with magnetic lines of Earth's magnetic field to point to the magnetic poles of the Earth.
What is 0 on a compass? ›Compasses have four cardinal points: north (N), east (E), south (S), and west (W). Some compasses also display 360 marks called degrees that can be used instead of or in addition to the needle which always points north. North indicates 0° (0 degrees). 90 degrees is East, south is 180°, and west is 270°.
Is there a 64 point compass? ›There may be 4, 8, 16, 32, 64, or even 128 compass points on a compass, depending on its size and accuracy.
What does red mean on compass? ›
Compass Basics
The first thing to realize when looking at your compass is that the floating needle is magnetized and the red end is always pointing towards magnetic north. No matter which way you turn the compass, the red needle stays fixed on magnetic north.
Hence Compass uses the permanent Magnet.
How many points does a compass have? ›The 16-point compass
For even more accurate readings, some compasses add eight more points to make a total of 16. Each of these points also has a direction. West-south-west (WSW) points to a direction west of south-west. Similarly, north-north-east (NNE) points north of north-east.
The compass was invented in China during the Han dynasty between the 2nd century BC and 1st century AD where it was called the "south-governor"(sīnán 司南) or "South Pointing Fish" (指南魚). The magnetic compass was not, at first, used for navigation, but for geomancy and fortune-telling by the Chinese.
Which way am I facing north or south? ›To understand where north, south, east, and west are, first point your left arm towards the sun in the morning. Image: Caitlin Dempsey. Now, take your right hand and point it towards the west. You are now facing south and your back is towards the north.
What is compass point strategy? ›A routine for examining personal reactions to an idea or plan. Description: Compass Points enables groups of learners to consider ideas and propositions from four different angles to prevent personal reaction or quick judgment. This routine works best when there are dilemmas or differing opinions.
How many points is 1 degree on a compass? ›The degrees unit number 11.25 ° converts to 1 point, one compass point. It is the EQUAL angle value of 1 compass point but in the degrees angle unit alternative.
What compass represents in life? ›Compasses represent motivation and inspiration. As a symbol, the compass signifies bringing motivation to a person feeling lost. It gives a sense of hope and inspires you to follow your heart and your rightful path. Also, compasses always point North, a direction which symbolizes progress, betterment and inspiration.
How do you use a compass short answer? ›One end of the magnetic needle is marked red, which represents the north pole. The other end of the needle represents the south pole. When these two directions are known, the other two directions can be estimated. In this way, a compass can be used to find the directions.
Why does compass always point north? ›Believe it or not, that's the way it is. Earth's south magnetic pole is near Earth's geographic north. Earth's magnetic north pole is near Earth's geographic south. That's why the north pole of a compass points toward north because that's where Earth's south magnetic pole is located and they attract.
How does a compass find north? ›
The magnetic field is a zone where the force is active along imaginary lines. From the south magnetic pole to the north magnetic pole, this force has an effect on all magnetized objects, such as the needle of a compass. Under the effect of Earth's magnetic field, the needle always points toward the north magnetic pole.
How did compass impact our lives today? ›Even though the compass was invented in Ancient China it has helped shaped the modern world in many ways. Today's compass is smaller, lighter weight, and more efficient than those from ancient times. We still use a compass to find our way on a trip or in a new place.