EXTRACTING AND CLEANING FOKEST TREE SEED. 13 



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 kiln 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 ro'om, or 1 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 w r arm 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 

 lor 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 



