This is Steve Ember with the VOA Special English Development Report.
Sawdust is what remains after trees and logs are cut up into boards for building houses and other structures. In many parts of the world, sawdust is considered waste. It is thrown away or left for the rain to wash away.
Sawdust is not often thought of as a fuel. It is difficult to burn, although fine particles of sawdust can explode if there is a fire or spark nearby. Yet it is possible to burn sawdust to provide heat or to cook food. One way is to build a stove from two round metal containers, or drums. To build one, place a one hundred liter drum inside a two hundred liter drum. The smaller drum is held in place by a false floor that connects to the larger drum.
Three metal legs support the large drum. The legs hold the structure above the ground. Beneath the false floor is a space where the sawdust fuel is placed. There are holes in the false floor allowing air to pass through.
As the sawdust burns, smoke passes from the small drum that does not have a cover to the larger drum that is covered. Pipes are placed in the wall of the outside drum to carry smoke outside. The space for the fuel and the holes in the pipes can be changed if more or less heat is desired.
To make the fuel, place the sawdust inside a round, wooden container that is about one meter across. Leave a hole in the middle. Make the sawdust hard by hitting it over and over again with a stick or stone. Then remove the wooden container very carefully.
The sawdust keeps the same shape it had when it was inside the wooden container. Place small pieces of paper into the hole. When the paper is lighted with fire from a match, the sawdust around it begins to burn. It is important that the sawdust be as dry as possible. With dry sawdust, this double-drum stove can heat a small room for six to eight hours.
During the first two hours of burning, there is enough heat at the center of the cover on the larger drum to boil water or to cook food. In addition to sawdust, other kinds of waste from sawmills can be burned in the stove.
You can get more information about how to make a double-drum stove from the group Volunteers in Technical Assistance. This group is on the Internet at vita.org. This VOA Special English Development Report was written by Gary Garriott. This is Steve Ember.