REFORESTATION ON 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 di*y 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- 
yantage 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 dr^^ 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- 
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 
