This is a fairly advanced science project, but an older child who is scientifically inclined will be stimulated by this challenging activity. Children will develop physical skills through building the telegraph and also use critical thinking in learning to understand how a telegraph works.
What this activity will develop:
Science and physical skills
What you'll need:
• Battery (size D)
• Telephone wire (2 feet)
• Utility knife
• Sheet of cardboard (4 feet by 8 feet)
• Three paper clips
• Flashlight bulb (nonscrew bayonet type)
• Masking tape
• Large brad
What to do:
1. Strip four inches of insulation from each wire end.
2. Spread a paper clip apart. Wrap one wire end around the small inner part of the paper clip.
3. Tape the wire on the paper clip with a small piece of masking tape.
4. Wrap the other wire end around another flat paper clip. Tape that paper clip to the bottom (flat) end of the battery.
5. Divide the cardboard sheet into thirds by making dotted lines at the intervals shown. Mark a cross in the middle of the narrowest piece.
6. Fold in the cardboard along the two dotted lines.
7. Cut the cross with the utility knife. Stick a pencil down into the cut to make a hole for the bulb.
8. Poke the bulb up through the cardboard.
9. Tape the battery to the cardboard as shown.
10. Hook the opened paper clip around the bulb base.
11. At the sides, tape the cardboard to the bulb is held against the battery. This completes the circuit, and the bulb should light up and stay lit.