This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
Secure some small wire and a very large can. Cut the wire into several pieces and bend them as shown at A cut the can and bend the side down as shown and punch holes to receive the upper ends of the wires. Make the holes so that the wires will be about 5/16 in. apart.