REFORESTATION OK THE NATIONAL FORESTS. 9 



for a stove and for trays around the sides. Often one room of a 

 cabin is used for drying and another for storing and extracting. 



Large tents with high walls make fair dry rooms; 12 by 16 foot or 

 16 by 20 foot tents, with 5 or 6 foot walls, may be used, but the larger 

 tents have given the most satisfactory results. Drying is more 

 difficult in tents than in buildings, but the tents have the great ad- 

 vantage of being readily transported from place to place where 

 cones are collected. Ordinarily, the largest tents are used for drying 

 and smaller tents for storing and extracting. 



Small, temporary drying rooms are almost invariably heated by 

 stoves. In buildings, box stoves equipped with drums have been 

 generally used with satisfactory results. In tents, low, conical stoves 

 have been more frequently used because they are cheap and easily 

 put up. They require constant attention, however, and empty cones 

 will not burn well in them. These are serious drawbacks, and the 

 use of box stoves with drums is preferable. 



The cones are usually spread in trays arranged in racks along the 

 sides of the room or tent. Trays are generally made of 2 by 4 inch 

 material, and vary in size from 2 by 3 to 3 by 4 feet. The larger 

 trays are difficult to handle, especially where space is limited, and 

 are used only with light cones. The bottom of the tray is wire 

 netting, usually with a one-half inch mesh for lodgepole pine and a 

 three-fourths inch mesh for larger cones. A tray space of 12 square 

 feet holds approximately 1 bushel of cones spread thinly. 



Cones may also be spread on pieces of wire netting stretched hori- 

 zontally between racks at intervals of 6 or 8 inches with a vertical 

 strip at each end to prevent their falling on the floor when raked. 

 Handling the cones is more difficult with this method, and the appa- 

 ratus is less easily transported from one place to another. With 

 either method a strip of canvas is spread on the floor to catch the 

 seeds as they fall through the netting, unless the floor is so smooth 

 that seed can readily be swept from it without the use of canvas. 

 It is essential that the trays be far enough apart, commonly from 

 6 to 8 inches, to permit ample circulation of air. There should be a 

 liberal supply of high registering thermometers to keep an accurate 

 record of the temperature in different parts of the drying room. 



On account of the high temperature and dry air prevailing in the 

 kiln room, extreme precaution must be taken to prevent fire. Where 

 water pressure is available,' a hose should always be connected and 

 ready for use. Chemical fire extinguishers should be secured as addi- 

 tional safeguards. If neither of these measures is practicable, sev 7 

 eral buckets should be kept filled with water, to be instantly available. 



Heating. — One of the most difficult problems in running an im- 

 provised kiln is to maintain a constant supply of heat and distribute 

 it evenly through all parts of the drying room. The first step should 

 62479°— Bull. 475—17 2 



