Robert North, age 11, of Visalia, Cal.if. ,for s question;

A match is a small, man‑made wonder which we tend to take for granted. Every day milliona of matches are rubbed against rough emery ‑ and almost always a little miracle happens. The match, made of ordinary wood or cardboard and chemicals,.bursts into flame. This magic is created by friction and chemicals with low kindling point,

Friction causes heat. You can prove this by gently rubbing your finger up and down the striking side of a match box. Your fingertip becomes warm. The rubbing was friction and the friction caused the warmth. This warmth is all that is needed to burst the match tip into flame.

Of course, this warmth is not enough to make your finger burst into flame. Nor is it enough to make a log of wood or a lump of coal catch fire. This is because fingers, wood and coal have higher kindling points. Kindling point is the temperature at which a substance catches fire. Some substances must get very hot before they burn. The chemicals on a match head need only the warmth created by rubbing on a rough surface.

When you build a fire in the grate you put in paper, strips of wood, then lumps of coal, You light a match and put the flame to the paper. This is because the paper has the lowest kindling point of the three fuels, It generates heat as it burns. The heat reaches the kindling point, of the wood. The wood catches fire. This generates more heat than the burning paper ‑ enough heat to reach the kindling point of the coal.

Kindling point is most important when chemicals are chosen to make the match head. Most of the recipes used for this job contain a phosphorus sulphide compound. Pure phosphorus has such a low kindling point that itis kept under water.

Potassium chlorate, saltpeter and red lead. may also be used in the recipe.

These chemicals are combustibles, which means they burn at the slightest excuse. Two chemical recipes are used to coat the tip of the workaday kitchen match. The match stick is made from prepared pine wood and coated with a substance which slows up the burning process. We do not want the flame to burn the match stick in a few seconds.

The tip of a kitchen match is dipped into two chemical baths. The chemicals in the first are highly combustible. But they will not ignite when you strike them on a rough surface. They need more heat than this to reach their kindling point.

The extra heat is provided for when the match gets its second chemical dip. This puts the eye‑tip on the end of the match. And the chemicals in this recipe are so combustible that they ignite when rubbed on a rough surface. As they burn, they make enough heat to ignite the chemicals in the first dip. The match bursts into flame in two little jerks,