Compasses are essential to orientation and navigation, having been in use for centuries. What you may not know about them is their Chinese roots – and that is what we will talk about in this article, alongside some interesting tidbits about their development over the years.
What was the Chinese compass made of?
Mathematicians and common folk used ‘loadstones’, which were suspended in the air as people believed they could point freely to a northern direction, and their magnetic properties allowed people to find gems underground as well as selecting suitable sites to build houses through Feng Shui principles. When these loadstones were placed in water, they could float, and point automatically to a southern direction.
History of the Compass
There is no set time in recorded history when the compass came to be, but historical estimates put its initial development during the Han dynasty (between the 2nd Century BCE to the 1st Century AD). During this period of ancient Chinese science and mathematics, the study of earth magic (which they called geomancy) was active.
The principle of this directional navigation was what created the first compasses. Initially, there were termed as ‘south-pointing spoons’, as the lodestone needles were shaped into spoons with their ‘handles’ facing south, and could turn easily over a smooth surface. It is unclear who came up with the compass, but they were mainly useful in navigational tasks during the Song dynasty especially in 1040 AD, especially by the Chinese military.
The loadstone was later replaced by iron needles in the 6th Century, and the compass was later recorded in Europe in 1190 AD. In the 17th Century, its overall design was changed to a parallelogram shape to make it easier to balance its pin, and 1745 saw an improvement from Gowin Knight – the Knight compass. Instead of iron, the compass now used steel needles that could hold their magnetism for a longer time.
This improvement was crucial to European dominance and colonialism, as it was going through the Age of Exploration and industrialization at the same time.
The versions of compasses used today
The first forms of the modern compass came around the year 1300, and they were referred to as ‘dry mariner compasses’. They had three elements: a needle that pivoted freely on a pin, a glass-covered box that protected the needle, and a gimbal that supported the box and its needle.
This resulted in ‘bearing compasses’, which could measure bearings more accurately in terms of directions of objects compared with the North. This compass later led to the earliest maps being made, with the first map variants appearing in the 16th to 18th Centuries. The variants of this compass are the prismatic and surveyor’s compasses.
The other form of the compass is the ‘liquid compass’ that was mainly used in sea navigation. It involved placing a magnetized card or needle in water, which gives a more stable reading. This was a more direct descendant of the initial compasses the Chinese used, but with some improvements.
How the compass works
The earth’s magnetic fields are essential to the operation of the compass, so it is important to understand the structure of the earth to know how they work.
The earth’s core is subject to gravitational pressure, so all the minerals and metallic elements it contains remain in a liquid or semi-crystal state. Due to the pressure and resulting heat, these elements move in various directions, leading to the formation of the magnetic field we see in a compass.
Similar to all magnetic fields, the earth’s field has two major poles – south and north. These poles tend to be slightly off from the rotational axis of the earth (the basis of geographic poles), but they remain close enough to accommodate polar adjustments when navigating the earth. These adjustments are referred to as declinations.
Therefore, compasses are lightweight magnets that work using magnetized needles hanging on rotating pivots, which allows them to react in a better and more accurate way to magnetic fields. The earth’s natural magnetic north pole will naturally attract the southern pole of the needle, so this is how sailors could know the northern direction.
What was the Chinese compass used for?
Unlike its use in Europe and the Americas, Chinese people at the time were not thinking of navigation when using compasses. Instead, they relied on these instruments as a way to bring their lives and environments into harmony, which developed into Feng Shui. In terms of the instrument’s earliest mention, it is in The Book of the Devil Valley Master.
Chinese people initially used the instrument in the study of geomancy, also called ‘earth magic’, as well as fortune-telling and worship. It was only later during the 11th to 12th Centuries that they started using it as a navigational tool, spreading it eventually through trade networks to the Arabs, the East African coast, South-East Asia, and Europe.
Why is the compass important?
The tool became indispensable to sailors and navigators because it allowed them to determine their direction without relying on astronomical cues as cultures did before. These cues were good when present, with examples including the Austronesian people that used the North Star in their navigation of the Pacific, but the problem was if there was bad weather or clouds that obscured the view.
Since compasses use magnetic needles and rely on the earth’s magnetic field, they function well even in cloudy weather, and they will always point to the north pole of the natural magnetic field. They also proved essential in navigation and map-making, resulting in the interconnected world we live in today.
Without the development of the compass, we would be geographically isolated in many ways, so they are very important in man’s history. They were first developed in China during the Song dynasty for worship, geomancy, and fortune-telling, but have become an essential aspect of our lives once their designs were improved for navigation.