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How to Make a Morse Telegraph Key

I worked for many years as a science teacher in Toronto, Ontario, and now am an occasional teacher working on the local school board.

The History of the Telegraph

The telegraph was the first invention that allowed people located in two different places to communicate effectively, by sending messages along wires using electric current. Its genesis began in 1820 and ended with the successful development of a device that could be used to effectively communicate across great distances: the Morse telegraph.

  • 1820: Danish scientist Hans Christian Oersted determined that an electric current could cause a magnetized needle to move. This discovery led directly to the development of the telegraph.
  • 1830: American Joseph Henry designed a simple telegraph using electromagnets, which was able to send signals over 1 mile (1.6 km) of wire.
  • 1837: William Cooke and Charles Wheatstone, two Englishmen, patented a different device using electromagnets and needles, which pointed at different letters to form a message.
  • 1837: Samuel F.B. Morse was credited with making the first practical telegraph.
  • 1840: Morse received a patent for this telegraph.

The telegraph required an operator who would send a message by using a device that varied the electric current flowing through the wires. As the amount of electricity changed, a device at the receiving end would convert the signals into a series of clicks. An operator translated those clicks into words, producing a message.

The telegraph became an efficient way of transmitting messages and information quickly to different locations.

  • Reporters used the telegraph to relay stories to their newspaper offices.
  • Armies during the Civil War also used the technology a great deal.
  • Ships at sea also utilized the technology for sending messages to other ships and to shore.

In 1929, the number of telegrams sent in the U.S. reached its peak as 200 million messages were sent that year.

Materials Required to Make a Morse Telegraph

  • double D battery holder (buy from radio shack or make one yourself)
  • 2 D batteries
  • 1 long iron or steel nail (least 2 1/2 inches long)
  • 1 short nail
  • 2"x6" piece of wood or styrofoam
  • 1 thumb tacks
  • 6 feet of thin, insulated copper wire
  • wire cutters or scissors
  • chain nose pliers
  • one large paper clip or long, thin steel wire
  • 4 insulated alligator clips (used in this project, they are helpful but not absolutely necessary)
  • tape
  • electrical tape

Building the Telegraph Machine

  1. Bend a large paper clip into one long, straight piece of steel and make a small bend at one end. It should measure about 6 inches in length once straightened. Too short and the wire will not have enough flex to bounce when the electromagnet is turned on and off.
  2. Create a loop at the other end.
  3. Cut two 6 inch+ sections of wire from the insulated copper wire spool.
  4. Strip the insulation off of both ends of the wires using wire strippers or by gently cutting the insulation with scissors and pulling off the plastic insulation. Place them off to the side until step 13.
  5. To make the electromagnet, take the large nail, wrap insulated wire in neat coils around the nail. Make sure to leave about 1/4 inch of free nail at the point so you can nail it to the board. You will need at least 100 coils to make a strong electromagnet. More coils will make a stronger magnet. Make sure to leave 5 or 6 inches of free wire on either end of the electromagnet.
  6. Using electrical tape, secure the wire loops so they do not come free.
  7. Strip the insulation off of each free end of this free wire using the method described in step 4.
  8. At one end of the wood board, hammer in your electromagnet nail.
  9. Take one of the free wires from the electromagnet and stretch out to the other end of the wood. Mark a spot ensuring that the wire has some slack.
  10. Wrap the bare wire around the thumb tack and press the tack firmly into this marked spot.
  11. Take the straightened paper clip made in step 1 and align it over the nail head of your electromagnet.
  12. Using the small nail, secure the straightened paper clip by hammering a nail through the loop. You will need to ensure that the bend loop at the other end rests about 1–3 mm above the nail head of your electromagnet.
  13. If using a home made battery holder, attach the bare end of your wires made in step 3 and 4, one wire to the positive terminal and the other to the negative terminal. If using alligator clips, attach them to the other bare ends of the wire.
  14. Note, my battery holder came with insulated copper wire attached to both the positive and negative ends of the holder. I used alligator clips attached to both ends of the wires made earlier and used these for attachment.
  15. Attach the positive end of the battery to the electromagnet using an alligator clip, clipped to the bare wire.
  16. Your Morse code telegraph is now ready to use.

How to Use Your Morse Code Telegraph

  1. Tap the alligator clip attached to the negative end of the battery on the paper clip.
  2. The straightened paper clip should be drawn down onto the nail head of your electric generator.
  3. If the clip sticks to the nail head and does not release, put a piece of cellophane tape on top of the nail head to prevent sticking.
  4. If it doesn't work, check all connections to make sure a complete circuit will be made when the switch is pressed.
  5. Try again.
  6. Practice your name and short phrases using the Morse code provided in this article and make history come alive!

A Great Project for Grade Students to Learn Electricity and Magnetism

This Morse code telegraph machine utilized the principles of electric circuits and electromagnetism.

The basic principle of the machine is as follows: When you tap the thumb tack with the alligator clip attached to the negative pole of the battery, you complete an electrical circuit. The electricity flowing through the coils on the large nail create an electromagnet which draws down the long, straightened paper clip. When you lift the clip off of the thumb tack the electrical circuit is broken and the electromagnet is deactivated.

These plans provide an excellent project for intermediate grade students learning the principles of electricity and magnetism. They would also be an appropriate project for physics students who could expand the above project by adding a receiver unit to send messages across the classroom.

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Sources Cited

  • World Book Inc. Inventions and Discoveries: Communication. Chicago: a Scott Fetzer Co. 2009.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.


Teresa Coppens (author) from Ontario, Canada on April 07, 2013:

farmloft, I am so very impressed with your grand daughter's skill. It took many tries and help from my husband and sons to get this project to work. Tell her bravo for me and I am so pleased that my directions helped her create a successful project.

farmloft from Michigan on April 07, 2013:

My granddaughter just made this with your directions for a 4-H project. She was so proud when she got it working. She's excited to find out how to make a receiver! Voted up

Teresa Coppens (author) from Ontario, Canada on July 18, 2012:

Daisy, thanks so much for sharing this. It took a long time to get the machine in working order. It is definitely a project for the patient one but well worth it when it starts to work.

teaches12345, I am hoping to turn this into a video hub with my son tapping out a morse code message. Maybe a quiz will be part and you can try to decipher the text of his message!

rebecca, thanks for stopping by. My kids are all kinesthetic hands-on types of boys. I love providing projects that are put together by hand and allow science learning at the same time. Its the way my kids learn best as I'm sure is true for many children and teenagers. Glad you enjoyed it!

Rebecca Mealey from Northeastern Georgia, USA on July 17, 2012:

This is very cool! I have always been sort of intrigued by Morse code. My uncle use to do short wave radio stuff long ago. Crazy!

Dianna Mendez on July 17, 2012:

I would love to see one of these in action. They are so fascinating. I could never understand the codes but they have come a long way from that now. (Still am trying to decipher the texting!).

Daisy Mariposa from Orange County (Southern California) on July 17, 2012:


What a fascinating article! Thanks for explaining how to build the Morse Telegraph Machine.

I'm going to pass the informations along to one of my cousins. His son likes to tinker with science projects such as this.

Teresa Coppens (author) from Ontario, Canada on June 29, 2012:

Morse code is provided. It was cool to get the electromagnet to work well enough to produce the clicks. Check back later if you get a chance. I should have a video up to show how the morse code works! Thanks for checking it out WhydThatHappens.

WhydThatHappen on June 29, 2012:

Cool how to, I'm not going to do it though because I would have to learn morse, but good!

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