Food Drying: the ancient art of preparing harvested foods for long-term storage. In some survival situations this may be the only way you will have to preserve the food you will need. Raw harvested foods are washed and cleaned, peeled and pitted, as appropriate, thin sliced (3/16 inches thick), and spread on trays which can be tilted to receive full direct sunlight. Before drying you should cook fish and meats, steam-blanche vegetables, and treat fruit with sulfur-dioxide gas. The latter will stop oxidation until the fruit can be fully dried. To improvise the sulfur-dioxide treatment, place sliced fruit on wooden trays in a wooden box. The box should have a 1 x 6 inch ventilation hole in the bottom, and a closed top. Set the box on bricks. Put one teaspoonful of sulfur for each pound of fruit in a clean pottery bowl. Burn the sulfur inside the box to treat fruit. During the sun drying process, screen or netting must be used to protect food from insects. The trays must be carried into a shelter whenever rain falls or dust blows. Dry food during a time period when you anticipate a succession of sunny days. Turn food slices daily until they appear to be very dry.  Then seal in an air-tight container until needed.  If you do not have adequate sunlight for food drying, construct your own dehydrator. Materials needed include a large wooden or metal box, a fan, a heating element, a thermostat, and drying trays with spacing supports. Construct a heated and ventilated drying box wherein a gentle flow of air moves over the food trays where food is being dried at a temperature of 140-145 degrees Fahrenheit.  Drying time will be from 4 to 6 hours. Store dried foods as indicated above. Dried fruits can be eaten directly. Dried greens should be cooked in boiling water for 5-10 minutes.  Meats can be added directly to stew because they are cooked before dehydrating. Reconstitute other dried foods by soaking in cold (salt-free) water for six hours.  Oven drying is not recommended because an oven holds a limited amount of food and the temperature must be kept below 145 degrees Fahrenheit. You must also provide for the escape of moisture by propping the oven door open several inches.