A compass is a navigational tool, which has been used for centuries to help direct people to their chosen location. The handheld device uses the frame of reference that is stationary relative to where the user is on the earth. There are four points on this frame of reference - north, south, east and west. These are known as cardinal directions. The compass will have a compass rose diagram inside which indicates all the cardinal directions, often simplified to ‘N, S, E, W’ rather than the full titles.
When using the compass, an arrow will point to the relevant cardinal direction you’re facing. For example, if you’re facing North, the arrow in the compass will point to the ‘N’ mark.
Some compass also have the angle markings in degrees, so north (the top marking) will be zero degrees, east will be 90 degrees, south will be 180 and west will be 270. The purpose of this is so that those giving directions can give a more detailed reading using the degrees around the compass. These are often known as azimuths or bearings.
Although newer technology, such as GPS satnavs and smartphones, are now more commonly used, compass are still used by campers, sportsmen and women and location specialists. In fact, some GPS (Global Positioning System) companies recommend using a compass with their GPS technology, as a compass can indicate a direction when GPS can’t.
Additionally, a compass benefits from being free of batteries or mains power, so they’re a lightweight and don’t require any extra power. Compasses can be pocket-size, or large enough to embed into the dashboard of an aircraft or boat.
eBay is an excellent place to go to find exactly the kind of compass required. You’ll be able to search for the particular type of compass you want, as well as the kind of accessories needed to go with it.
Types of compass
There are two different types of compass - the magnetic compass and the gyrocompass. The magnetic compass is magnet-based, and works with the earth’s magnetic field to point to the correct magnetic pole. The gyrocompass has a spinning wheel. This wheel’s rotation works dynamically with the rotation of the earth, to make the wheel precess, therefore losing energy to friction until its axis of rotation is parallel with the earth's.
While there are only two main types of compass, there are plenty of variations. Many boats have an inbuilt compass, as compass navigation is still standard for a lot of maritime navigation. Aircraft often use an inbuilt compass. This form of navigation instrument is particularly good for finding direction in the water. Watches often have a compass element, and a compass can even be found on smartphones - although these are digital compasses.
It’s believed that the magnetic compass goes all the way back to the Chinese Han Dynasty, where it was invented to assist with divination. Divination is a way of discovering an answer for a situation or question, based on rituals, processes or even paranormal knowledge. The Chinese believed they could find gems and choose the right location for a house. Many religions also used a compass for religious and spiritual means, including Feng Shui and astrological readings. Later on, the magnetic compass was used for the purpose we use it for today - navigation.
By 1040-1044, the magnetic compass was used in Song Dynasty China by the army to navigate, and was later used for maritime navigation in 1117. The first compasses were made of a naturally magnetized ore of iron called lodestone. The Chinese discovered that suspended lodestone turned freely but always pointed towards the correct direction.
It’s believed that the compass made its way to Western Europe sometime between 1187 and 1202, and also arrived in Persia by 1232.
The dry compass was invented much later, in 1300, in Europe, but was superseded by the liquid-filled magnetic compass, which arrived in the early 20th century.
A basic magnetic compass is made from three main parts:
- The needle, which is usually made from a slice of magnetic metal
- The dial, which is the background which has the north, south, east and west poles marked out, as well as the degrees on more advanced models. This is usually made from card, although the more expensive models have plastic or metal dials.
- The case. The case can come in a variety of materials, including plastic and metal. Some cases have a bubble-like viewer to make it easier to see the reading.
There are some compasses that come with additional extras, including mirrors to find out the direction of things in the distance, and transparent bases so they can be applied and used over a map. Parts can be bought on eBay to change the look or options a compass offers.
The needle of a compass is rarely defective, but can give incorrect results if it is exposed to a strong magnetic or electric current. This can ‘remagnatise’ the needle so it points the opposite way. Therefore, it is important to keep it away from such forces.
Some compasses now come with additional features, such as an included GPS feature, a clock or a thermometer, to give users a wider range of tools for their navigation.
How To Buy A Used Compass On eBay
eBay has plenty of choice when it comes to buying a used compass. There are plenty of options, from a magnetic compass and the gyrocompass to more advanced compasses for boats and aircraft. On eBay, sellers are renowned for their competitive pricing and wide range of products, coupled with the flexible payment options available by buying on eBay. Additionally, eBay can offer a much wider range of compass styles and accessories that many of the high street competition.
It is important to find the right kind of compass for your needs. For example, there are plenty of simple options for a kids’ compass. There are also plenty of pro compass styles, including several designed especially to be mounted on a camera.
Compasses can be found in the Sporting Goods section, across a number of sections. The simplest way to find a wide range of compasses is to search for ‘compass’ in the search bar.
Alternatively, type in specific search terms into the search box provided on every page. Using specific searches such as “kids’ compass” or “gyrocompass” or other terms you require will help locate the desired item.
When you find an item of interest, make sure you thoroughly look through the listing and read all the available information. Do your research, to make sure the item listed matches descriptions elsewhere. If there are few photos, or low quality photos, contact the seller for a clearer photo to make sure you’re getting a good quality compass. Also, check their feedback to make sure they have a good reputation and feedback. Finally, contact the seller if you have any questions.
There are several thing to consider when buying a used compass. Firstly, are there any broken parts. A broken baseplate, case or needle might impact on the accuracy of the reading. A chip or problem with the plastic or glass may lead to a leak of the fluids inside the compass.
Secondly, does it have all the compartments you require. Many compasses have declination adjustment included, which finds the difference between magnetic north and true north. This is important as declination can vary from place to place, so a compass with declination adjustment will be able to counter for this.
Thirdly, is it being sold at the correct value. Some used compasses have a higher value because they have a long history. However, it’s important that you do your research on the particular model before bidding, as there are some more modern duplicates. Check to see if they have the correct markings or original packaging.
Finally, if you haven’t used the particular brand of style of compass before, a set of instructions are useful and often come with the compass when bought new. A compass is rendered useless if the person purchasing it does not know how to use it - or uses it incorrectly. If the seller doesn’t have the instructions, ask additional questions or search online for instructions.
If you’re interested in the item, you can Bid on it, Buy it Now or put in your Best Office. These options depend on whether the seller offers them. You then have the option to pay with PayPal , to make sure the purchase goes smoothly. Remember - eBay users are protected by the Buyer Protection Program .
Buying a used compass on eBay requires some research and knowledge of what compass would suit your needs most. Different compasses suit different requirements, and there is now a wide range to choose from for all needs. Buying through eBay makes it easy to track down rare or affordable parts for your navigating, sports or hobby needs.
You can also buy a new compass on eBay, as well as cases and accessories for compasses.