Make a Compass

When people think of instruments that help with direction finding, the first one that springs to mind is probably the magnetic compass. It is the oldest instrument for navigation and has been a vital tool for navigators at sea for centuries.

No matter where you stand on earth you can hold a compass in your hand and it will point toward the north pole. What an unbelievably neat and amazing thing! Imagine that you are in the middle of the ocean, and you are looking all around you in every direction and all you can see is water, and it is overcast so you cannot see the sun… how in the world would you know which way to go unless you had a compass that told you which way is “up”?

a compass gave humans an easy and inexpensive way to know which way to go. But how can you make a compass?

Adult supervision is required

Information Gathering:

Find out about compass and how it works. Read books, magazines or ask professionals who might know in order to learn about the structure of a compass. Keep track of where you got your information from. Following are some sample information that you may find.

A compass is an extremely simple device. A magnetic compass consists of a small, lightweight magnet balanced on a nearly frictionless pivot point. The magnet is generally called a needle. One end of the needle is often marked “N”, for North, or colored in some way to indicate that it points toward north. That’s all there is to a compass.

Using the compass:

The first thing you need to learn, are the directions. North, South, East and West. Look at the figure and learn how they are. North is the most important.

There are several kinds of compasses. Let’s take a look at a navigating compass:

You see this red and black arrow? We call it the compass needle. Well, on some compasses it might be red and white for instance, but the point is, the red part of it is always pointing towards the earth’s magnetic north pole. Got that? That’s basically what you need to know. It’s as simple as that.

But if you don’t want to go north, but a different direction? Hang on and I’ll tell you.
You’ve got this turnable thing on your compass. We call it the Compass housing. On the edge of the compass housing, you may have a scale. From 0 to 360 or from 0 to 400. Those are the degrees or the azimuth (or you may also call it the bearing in some contexts). And you should have the letters N, S, W and E for North, South, West and East. If you want to go in a direction between two of these, you would combine them. If you would like to go in a direction just between North and West, you simply say: “I would like to go Northwest “.

Let’s use that as an example: You want to go northwest. What you do, is that you find out where on the compass housing northwest is. Then you turn the compass housing so that northwest on the housing comes exactly there where the large direction of travel-arrow meets the housing.

Hold the compass in your hand. And you’ll have to hold it quite flat, so that the compass needle can turn. Then turn yourself, your hand, the entire compass, just make sure the compass housing doesn’t turn, and turn it until the compass needle is aligned with the lines inside the compass housing.

Now, time to be careful!. It is extremely important that the red, north part of the compass needle points at north in the compass housing. If south points at north, you would walk off in the exact opposite direction of what you want! And it’s a very common mistake among beginners. So always take a second look to make sure you did it right!
A second problem might be local magnetic attractions. If you are carrying something of iron or something like that, it might disturb the arrow. Even a staple in your map might be a problem. Make sure there is no magnetic object around. There is a possibility for magnetic attractions in the soil as well, “magnetic deviation”, but they are rarely seen. Might occur if you’re in a mining district.

When you are sure you’ve got it right, walk off in the direction the direction of travel-arrow is pointing. To avoid getting off the course, make sure to look at the compass quite frequently, say every hundred meters at least.
But you shouldn’t stare down on the compass. Once you have the direction, aim on some point in the distance, and go there. But this gets more important when you use a map.

There is something you should look for to avoid going in the opposite direction: The Sun. At noon, the sun is roughly in South (or in the north on the southern hemisphere), so if you are heading north and have the sun in your face, it should ring a bell.

Question/ Purpose:

How does a compass work? The purpose of this project is to make a working compass using material that can be found at home.

Identify Variables:

Since compass is an instrument that functions based on a moving magnet, the strength of the magnet and the friction are variables that can affect it’s function.

Hypothesis:

My hypothesis is that any floating or hanged magnetic object can be used as a magnetic compass

Experiment Design:

Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure.

Experiment 1: Make a Compass

Make a simple compass to find magnetic north, or south, depending on where you live.

Equipment:

1. Sewing needle ~1 inch (3cm?) long.
2. Small bar magnet. Refrigerator magnets may work if you don’t have a bar magnet.
3. A small piece of cork.
4. A small glass or cup of water to float the cork and needle.

Safety:

Needles are sharp.. treat appropriately.

How to do the experiment:

1. Your compass will work better if you first run a magnet over the needle a few times, always in the same direction. This action ‘magnetizes’ it to some extent. Drive the needle through a piece of cork. Cork from wine bottles works well. Cut off a small circle from one end of the cork, and drive the needle through it, from one end of the circle to the other, instead of through the exact middle – be careful not to stick yourself!

2. Float the cork + needle in your cup of water so the floating needle lies roughly parallel to the surface of the water.

3. Place your ‘compass’ on a still surface and watch what happens. The needle should come to point towards the nearest magnetic pole – north or south as the case may be.

4. If you want to experiment further, try placing a magnet near your compass and watch what happens. How close or far can the magnet be to cause any effects?

Explanation:

The earth produces a magnetic field. This field, although weak, is sufficient to align iron and other paramagnetic compounds such as your needle within it. By floating the needle on the cork, you let it rotate freely so it can orient itself within the earth’s magnetic field, to point toward the north or south poles of the planet.

Experiment 2: Make a Compass

While searching around the house, I noticed that we have no cork and no sewing needle. So I decided to replace the cork with any similar object such as wood or Styrofoam and replace the needle with a paper clip.

Procedure:

As a quick test, placed the paper clip over a piece of Styrofoam and placed them in water to see if they can stay in balance. Then magnetize the paper clip by rubbing it against a magnet and repeat the test again.

When I did this test for the first time, I noticed that the Styrofoam turned and the paper clip stayed in a north south direction. Obviously my paperclip was already magnetized. So I did not have to rub it against a magnet. It was an instant compass.

Now if you like, you can hide a magnet inside a Styrofoam and have a simpler compass. To do that cut a circle from a Styrofoam sheet. (We cut a polygon for the picture, because that was easier to cut). Make a grove in the center of that so the magnet can be hiding inside the grove.

Cover the Styrofoam with a thin layer of wood glue and place another another sheet of heavy paper over that so the magnet will be hidden. Wait until the glue is fully dry. Your compass is now ready for test.

Place it in water to see what direction does it stand. Mark north, south, East and West on that, so it will be ready for use.

Any time that you want to use your compass, you will need some still water. One inch deep plate filled with water is perfect for this test.

Experiment 3: Make a Compass

The first two experiments are based on a floating magnet. This experiment will use a magnet hanged from a tread.

Procedure:

Get samples of bar magnet, cow magnet, horse shoe magnet and latch magnet and hang them with a thin tread, at least two feet long. Make sure that you are not close to a large metal object while doing this experiment. See if they tend to stay in a certain north south direction.

This image shows a 2 inch cow magnet hanged from a tread. (Search to see why do they call it cow magnet?)
In our experiment the magnet clearly stopped in a north-south direction.

This image shows a small horse shoe magnet hanged from a tread. It seems that horseshow magnet is wondering around and does not focus on any specific direction.

Experiment 4: Use a magnet to plot a path

Hikers, tourists, travelers and all those who enter an unknown area may use a compass to record their path and use it for their return. Using a compass is one of the methods that can help a traveler not to get lost. In this experiment you will record your path in a short trip in your neighborhood, a park or a market.

Adult supervision is required.

Procedure:

Use a compass that is graduated from 0 to 360 degrees.

In the beginning of your path, hold the compass so that the arrow stays on the N. Look at the path and find the angle on the compass that aligns to the path. Record the angle and the start time in your data table. Start walking at a constant speed until the path turns or you have to turn on a crossing. This point is the beginning of a new path. Stop and write the time for the end of the first section.

Again hold the compass so that the arrow stays on the N. Look at the new path and find the angle on the compass that aligns to the path. Record the angle and the start time in your data table. Continue walking until you have to turn again.

Continue this process and record the start time, end time and angle of each portion of the path. Your data table may look like this:

You can later use the above table to draw your path. You may draw a 5mm line for each minute of walking.

How to use this data table for your return path?

Start from the last line of your data table. Read the angle. Then find its opposite angle on your compass. That is the angle that you must go back. The opposite angle can also be calculated by adding or subtracting 180 from the recorded angle. You need to calculate the return angle for each segment of your path.

You must also subtract the start time from the end time to calculate the time distance for each segment of your path.

Materials and Equipment:

List of material can be extracted from the experiment section.

Results of Experiment (Observation):

Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental “runs.” During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered “raw data” since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.

Calculations:

No calculation is required for this experiment.

Summary of Results:

The bar magnet and paperclips, could make good working floating compasses.

Bar magnet also can be hanged and be used as a compass. In our experiment the magnet clearly stopped in a north-south direction.

This image shows a small horse shoe magnet hanged from a tread. It seems that horseshow magnet is wondering around and does not focus on any specific direction.

Write more if you need.

Conclusion:

A compass is an instrument with a magnetized needle that points north. By knowing where north is, you can use the compass to find other directions.

The Earth contains metals that are naturally magnetized. One end of the compass needle will always point toward the North Pole because of the Earth’s magnetic properties.

Bar magnet can be hanged by a tread or be mounted on a floating object in order to be used as a compass, but horse shoe magnet can not. A possible reason is that the north and south pole of a horse shoe magnet are almost faced each other and are voiding each others magnetic force.

Write more if you need.

Related Questions & Answers:

What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.

Possible Errors:

If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.

If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.

References:

List of References:

http://www.fsea.org/pdf/BC1%20Basic%20Compasspdf.PDF

http://www.smartcenter.org/smartcenter/compass.pdf

http://www.dot.state.mn.us/aero/aved/publications/skyslimit/compass.html

http://www.miamisci.org/ecolinks/activities/Geosphere/Compass/

http://www.fengshui4free.com/compass.htm

http://www.kyes-world.com/compass.htm