Make Your Own Telegraph

(Adult Supervision is Advised) MATERIALS: 9-Volt Battery Copper Wire Nail Pieces of Wood Thin copper plate Copper Screws   In 1847, Samuel Morse received the patent for his invention of the telegraph. Many years before cell phones, the only method of communication was sending someone a message by a horse rider. The telegraph became the first method for instant delivery of messages and the starting point for future technology. Follow these steps and you will be sending Morse Code messages using your very own telegraph. MAKING YOUR TELEGRAPH: In order to make a telegraph, you will be making two devices: a ‘sender’ and a ‘receiver’. The ‘sender’ will be used to send the outgoing message and the ‘receiver’ will be used to receive the incoming message. Making the SENDER:

• Take one piece of wood that is approximately 50mm x 100mm x 20mm and set it in front of you.
• Cut out a thin strip of bendable copper about 15mm x 60mm.
• Bend a portion of the copper upward and screw the flat end into the piece of wood.
• Place a screw under the bent end of copper, so that the copper will touch the top of the screw when pressed down.

Making the RECEIVER:

• Nail 2 pieces of wood together into and L shape.
• Slightly hit a nail into the open side of the wood and wrap the nail will copper wire about 20mm in diameter, using tape to hold it in place, if necessary. (The nail needs to remain 3-4mm below the upright side of the L shape in the wood.)
• Cut out another piece of bendable copper, the same size as used in making the Sender, making sure it ‘hovers’ over the head of the nail.
• Join one end of the coiled wire to the fixed end of the sender and the other end to one of the battery terminals. Connect the other battery terminal to the screw beneath the free end of the sender strip.

This completes the construction of your very own telegraph and you can now start sending Morse Code using the chart we have provided!

Morse Code Chart

WHAT WE HAVE LEARNED: When the 'sender' switch is pressed down, the strip makes contact with the screw underneath and the electrical circuit is complete. Current then flows through the coil turning it into an electromagnet and pulls or attracts the copper plate above it to make a clicking sound. When the sender switch is released, the current does not flow through the coil anymore, the magnetism is lost, and the copper plate is released. These clicks are used to send messages in Morse code, clicking quickly for dots and slowly for dashes. TERMS TO UNDERSTAND: Morse Code: A telegraph code in which letters and numbers are represented by strings of dots and dashes. Electromagnet: Type of magnet whose magnetic field is produced by the flow of electric current. The magnetic field disappears when the current ceases.