Niall Fraser, age 12, of Vancouver, B.C., Canada, for his question:

HOW DOES A SAFETY MATCH WORK?

Highly combustible phosphorous material, combined with an oxygen producing compound and put at the end of a paraffin dipped wooden splint, produces a kitchen match that will strike anywhere and produce a flame.

Much less dangerous is the pocket folder of paper safety matches.

Safety matches are made by putting phosphorous and sand on the striking surface outside the match folder. The match itself, which can be made of either paper or wood, is topped with a cap of chlorate of potash. The match can only be ignited when it is scratched on the head by the special surface  there's nothing else that will do the trick.

Safety match covers, often colorful and interesting, are collected by many people as a hobby.