If you were a boys or girls scout, you learned to use the compass as a basic survival skill. Likewise, European explorers traveled to the Americas with the help of the compass. The compass, a device that gives us the directions of north, south, east, and west, is an age-old invention that still works wonders. But you may be wondering about the origin of this useful device, which has two different versions.
The Traditional Compass
One type of compass is based on natural magnetic forces within Earth and points to the magnetic north direction, which is close to true north. This compass is the one most of us are familiar with and which has an ancient origin dating back to thousands of years ago.
The origin of the compass traces back to the ancient Chinese, whose earliest compass consisted of a lodestone spoon on a bronze plate. As far back as 221 B.C., the Chinese may have used lodestone, a mineral that is black in color and has a metallic shine, for fortune-telling and predictions.
Lodestone has the uniqueness of being the stronger of two minerals with natural magnetism, or attraction to iron, while other minerals do not have this property. By 1000 B.C., the Chinese put lodestone in water, thereby creating a compass that pointed south and helped to find locations of positive energy according to “Feng Shui” philosophy.
Some scientists have claimed that, based on archaeological findings, the ancient Mexican people known as Olmec used a magnetic device for making predictions as early as 1400 B.C. However, this claim does not have wide acceptance.
Meanwhile, the Chinese first used a needle with a magnetic mineral around 70 to 80 A.D., according to literature published at that time. During the Song Dynasty in 1040 A.D., the Chinese advanced the role of magnetism as a direction locater when inventors heated metals, like steel, resulting in low-magnetic device that could help people find their way at night.
While the Chinese may have used the compass earlier for finding locations, for certain they used the compass for navigation in 1119 A.D. Mostly, the Chinese used the wet compass, which contained water. Yet they also had a dry compass, with a wooden turtle holding a needle and the lodestone covered in wax that appeared around 1150 A.D. When the Chinese spun the turtle, its tail always pointed to the north direction.
Perhaps through Muslim traders along the Silk Route, the compass reached the Europeans, who created their own dry compass design by 1269 A.D. This design used a pivoting needle attached to card and located in a glass-covered box to pinpoint the direction. By the late 13th century, Europeans no longer needed to confine sea voyages to months of clear skies because of the compass.
Later, other types of magnetic compasses appeared, such as a surveyor’s compass to measure landmarks and an improved liquid compass that withstood wear better and stayed steadier. Also, people used the compass in mining, map-making and building construction, besides navigation. Likewise, Muslim scientists invented one compass for prayer times and another type, known as the Qiblah compass, to locate the direction of Mecca.
In modern times, the compass may have oil, alcohol, or kerosene as the liquid, as well as key points, such as North, South, East, and West, written with illuminating material for easy reading at night. In addition, a military compass uses electromagnetic induction to dampen the needle.
The Gyro Compass
One version is the gyro compass, which has a spinning wheel that rotates and aligns itself parallel with the Earth’s axis, thereby locating true north. The gyro compass, which sometimes spelled with a hyphen or as gyrocompass, has the advantage of not being affected by outside magnetic forces. So, the gyrocompass came in handy on ships with steel and other metals, where the traditional compass was not reliable.
The origin of the gyro compass goes back to 1890, when G.M. Hopkins came up with the first, electrically-driven gyroscope, which had a spinning disk on a base that stayed in place when the base was moved. New York-born Elmor Sperry saw how they this invention could become a navigation tool and he invented the gyro compass, which he patented in 1908. The Navy embraced the gyro compass and used it extensively in World War I.
The Compass Lives On
Whether you think of the gyro compass or the traditional compass, this device will continue to help people find their way around. You might see improvements in the compass design in the years to come, but the device will stay true to its origin.