Denise Leeth, age 12, of Visalia, California, for her question:
How do, they get the lead into. a pencil?
As you know, the lead in a pencil is not really lead, which is quite a firm metal. It is graphite, which is a soft, dark carbon material. And, when you examine a pencil, it is natural to wonder how in the world they managed to squeeze the soft graphite down the middle. Actually, the manufacturers have a much simpler say to do the job. They begin with slats of cedar wood, just long enough to make pencils.
The slats are grooved from end to end. The carbon is molded into long narrow threads, just thick enough to fill a pencil. These are placed into the grooves and grooved strips without graphite are placed on top. When two grooved strips are fitted and sealed together, there is a thread of graphite down the center. The seal along each side is hidden when the pencil is sanded and painted.