These are the parts that you will need:
• A board. Any piece of wood will do. Just make sure it is at least eight inches long and six inches wide. It can be bigger if you like.
• A piece of cardboard tubing. This should be two inches in diameter, like the tubes on which ribbon is wrapped in five-and-ten-cent stores. The tube should be six inches long.
• A spool of insulated copper wire. You may have to buy this at a radio store. Ask for No. 28 gauge; this is just the right size. The wire will cost about 75 cents.
• A pair of earphones which you can put over your head like the pilot of a jet airplane. The phones can be bought at a radio store for two or three dollars.
• Three new nails. The nails can be either an inch or two inches long. Anything you have will do.
• Four metal thumbtacks, not plastic tacks A used blade that fits a safety razor. A plain white-looking blade often works better than “blue” blades.
• A big safety pin
• A pencil with a fat lead
Let’s put all the tools and parts on a table like this and see if we have everything before we begin: