Two strands of copper wire (roughly 1-2 feet, each) One clear glass jar Small glass jar for smaller bulb Five or more batteries Four crocodile snips

Pencil lead actually isn’t lead at all, it is graphite. Graphite is an electrical conductor, making it a good filament for homemade light bulbs.

If you are making the hooks yourself, make them big enough to fit over the end of the battery.

Wrap the tape tightly enough around the batteries so that they hold together. You may need to overlap the tape a few times. You must arrange the batteries so that there is a positive node on one end, and negative on the other.

You can reverse the red and black if you want– you just need different wires on each end. Remember you only want to hook up one wire right now.

The longer the graphite, the longer your bulb will last. Use some tape, glue, or modeling clay to help stick the clips face up.

The size of the jar does not matter, but the jar should be clean. If the jar has a label, it would be a good idea to remove it; this will make it easier to see the light.

Check the graphite thickness. While larger thicknesses work, 0. 5 mm seems to work best. Add a few more batteries. Also, make sure that the ones you have are touching end to end. Make sure the wires are snug and well-connected to the batteries.

Use small wire cable cutters to cut the copper wire.

You need to expose the end of the wire, otherwise you won’t be able to complete your circuit.

You can reuse an actual cork from a wine bottle, or you can buy a package of corks from the craft store.

If you need to, strip the shielding off of the wire to expose the metal.

This will hold onto your filament, which is the part of the bulb that actually lights up.

Use a pair of good wire cutters for this.

You can make an actual 5-strand braid, or you can just gather the ends together, then twist them like a rope.

Make sure that the jar is clean, and that the label has been removed.

You can use any battery, but starting small is usually best. C or D batteries (1. 5 V each) will do the trick. If you’re not getting enough light, try attaching your batteries in series.

Ensure all the ends are touching. You must have a complete, unbroken circuit to get light. Thin out the filament. Try it with only 3-4 strands. You could also replace the iron with graphite, as mentioned in method one. Add more power. Use a bigger battery, or attach multiple batteries together, for more power and more light.