Samuel B. Morse’s invention of the telegraph was a major step forward in rapid communication. The code used on the telegraph, a system of dots and dashes, was named after him. Materials you will need:
- Energizer® Power Pack
- Strip of 3" to 5" metal from can
- 3" x 1" x 1" block of wood
- Number 22 insulated wire
- Switch or alternate commercial knife blade switch
- Piece of wood for base
- 4 nails
- 1. Nail the wooden block to one end of the board. Drive the nail of the electromagnet into the board in front of the block (wood block should be slightly higher than the nail head). Use nails to secure the metal strip on top of the block and bend it if needed so that it is just above the electromagnet nail.
- 2. Connect one end of the electromagnet wire to the switch and the other end to the negative of the Energizer Power Pack. Connect the positive of the Energizer Power Pack to the other end of the switch.
- 3. With the switch open no electricity flows through the circuit and the metal strip is suspended above the nail.
- 4. When the switch is closed electricity flows through the circuit and creates a magnetic field around the electromagnet. The magnetic field pulls the strip of metal to the nail.
If needed adjust the distance between the metal strip and electromagnet nail head so that it clicks when the switch is opened and closed. You can then open and close the switch at different speeds to adjust the time between clicks. You now have a working telegraph.
When telegraphs were used to send messages across the country a sender would operate a switch at one end of a circuit. The circuit wires would run long distances to an indicator such as a buzzer at the other end. The message receiver would listen to the buzzer and use Morse code to convert the message.
About one-fourth of a second and the dash is three times longer than the dot. You can go to the library or search on line for a Morse code table that you can use with your friends to send messages.
You could also make a simple alternate switch out of another small strip of metal as shown below.
Pressing down on the metal strip closes the switch and completes the circuit.