EXTRACTING AND CLEANING FOREST TREE SEED. 3 
by inclosing the stovepipes in jackets, which need not extend farther 
than the openings where the pipes pierce the floor. 
IDEAL DRY HOUSE. 
An ideal dry house contains three stories, built. in the side of a 
hill to take advantage of gravity, and to utilize the earth which 
partly surrounds the building to prevent the escape of the heat. The 
cones are unloaded into the third story from a road on the hillside. 
From this storeroom, or preliminary drying room, the cones are 
dropped to the second floor or kiin room. The ground floor contains 
the extracting room, furnace, and other equipment. The furnace may 
consist merely of a large box stove, burning long sticks of wood, . 
inclosed in a galvanized-iron jacket packed with mineral wool or 
asbestos to prevent radiation of heat. From this jacket the heat is 
conducted through two pipes into the drying room or kiln. The 
heat is thus used where it is most needed, and its escape into the 
space about the furnace prevented. The building can be built, if 
necessary, only two stories high, in which case the cones are either 
unloaded directly into the second story or kiln room, or stored on 
the ground floor until ready for drying. 
VENTILATION. 
The proper ventilation of drying rooms, while less difficult than 
the even distribution of heat, is fully as important. All undried 
cones contain some moisture. As this is driven off the air becomes 
more and more saturated. Saturated air not only prevents rapid 
drying of the cones, but may injure the seed embryos. German ex- 
periments indicate that damp cold air is much more harmful to 
seeds than dry warm air. Some method of ventilation—letting in 
fresh, dry air and letting out moist air—is, therefore, essential. 
The method usually employed is to insert one or two ventilators 
in the roof of the building or tent and also in openings near the floor 
for the entrance of fresh air. The amount of air taken in and let 
out can be regulated by adjustment of the ventilators. Tents are 
usually so open at the bottom that it is not necessary to make spe- 
cial provision for fresh air. Where the drying room is heated from 
below, fresh air can be admitted through dampers or ventilators in 
the jacket surrounding the stove. Vents to maintain circulation 
should also be provided in the roof of the drying room. 
While usually the best practicable, these methods of ventilation are 
necessarily crude and wasteful. As the air cools and absorbs moist- 
ure, it becomes heavier and sinks to the floor. Vents in the roof 
carry off much of the hot, dry, light air which should be retained. 
A certain amount of heavy moist air is, however, carried out with 
