James Andrews  age 10, of Miami, FL, for his question:

Is it true that one spark can start a big forest fire ?

    Everyone who has visited our beautiful forested regions has seen the roadside pictures of Smokey Bear   the cute little brown fellow with straw hat and blue jeans whose job is to warn us of the danger of forest fires. A camp fire left smoldering a lighted cigarette or one half burned match, he tolls use can turn miles of lush green beauty into miles of charred wasteland, Smokey Bear was chosen by the rangers as a symbol to point up to us the danger of carelessness. He

knows his business and he is right   one flying spark can start a raging forest fire forest fires in fact any fires is a chemical process.  It is the breaking dawn of molecules  into.  smaller particles most of which go off into the air as water vapor and gases. The molecules broken up in the chemical process of a forest fire were first put together by another chemical process. All summer longs the green leaves of the woods and forest are busy using sunshine to make plant cells. This

is a chemical process in which the energy of sunlight is used to bind atoms of carbons water and minerals to make molecules of wood and plant cells.

The green leaves use their magic to blend molecules of sugar! starch and cellulose   the materials from which plants feed and build new cells. The raging fire breaks apart the molecules of which the plant is made. One is a chemical process in which heat and energy are used to blend atoms into molecules. The other is a chemical process which breaks apart molecules and releases the heat and energy which bound them together till that is needed to change the building up process to the breaking down process is heat. A small spark may be warm enough to raise the temperature of a dry leaf to its kindling point. It then bursts into flames releasing in the form of heat the energy which bound together the atoms in their molecules.

This newly released heat warms the air around another leaf or dry twig, They too, start to smolder and burst into flame. The cruel flames are soon creeping along the forest floor. The air around small bushes is raised to kindling point and they too soon join the growing blaze. Sooner or later the creeping fire reaches the base of a giant tree. The air around the ancient wood reaches kindling point and greedy tongues of flame begin to lap up the greet tree.

Smoke curls up and drifts on the passing winds. Sparks crackle and shoot up to fall and carry the fire further afield. All the work, the skill and the courage of the rangers is needed to keep such a fire within bounds. And even with all that, many a forest fire gets out of hand. Before it has had its fill, vast acres are left as sooty ashes, huge trees are blackened stalks of charred wood. And all the heartbreaking destruction could have been started by one small spark.