8 BULLETIN" 475, U. S. DEPARTMENT OF AGRICULTURE. 



large quantities of cones have been gathered. There are smaller 

 drying plants designed for use only on the National Forest where 

 they are located. These are quite simple in their plan and of rela- 

 tively cheap construction. 



Figure 1 shows the plan of a small cone-drying plant on the 

 Arapaho National Forest, Colo. It has been used exclusively for the 

 extraction of lodgepole-pine seed and has proved quite satisfactory. 

 The pine cones are collected in October and held in a storage bin 

 from 12 to 15 months before the seed is extracted. This bin holds 

 approximately 6,000 bushels of cones and is divided into several 

 compartments. A passageway between these permits the removal of 

 the cones to the drying room. The sides and end of the bin are 

 constructed of 4-inch boards spaced a short distance apart to facili- 

 tate the preliminary air-drying of the cones. The kiln or drying 

 room proper is constructed within the main building and is located 

 directly over the furnace in the basement. This kiln is 11 feet by 9 

 feet in size, outside dimensions, and is made as tight as possible. 



When the cones are to be opened, they are placed in shallow trays 

 2 feet 10 inches by 7 feet in size, which have one-fourth inch mesh 

 hardware cloth bottoms. The capacity of each tray is 1 bushel of un- 

 opened cones. The trays are braced at the four corners on the bottom 

 with 2-inch pieces of wood, so that when the}^ are piled in tiers the air 

 may circulate freely between them. Three tiers of trays. 12 per tier, 

 constitute a charge for the kiln. The trays are loaded on a truck, 

 wheeled to the kiln door, and in one lot shoved into the kiln on rolls. 

 Each charge of cones is dried for eight hours, and the plant is run 

 continuously, except Sunday, in three eight-hour shifts daily. 



The kiln is heated by means of four hot-air flues coining from the 

 furnace and terminating at the floor of the kiln. Opened cones ex- 

 clusively are used for fuel. When removed from the kiln, the cones 

 are placed in a large hopper and gradually fed into the drum of the 

 " shaker." As the shaker revolves, the seed are separated from the 

 cones and fall upon a canvas spread on the floor. The open cones 

 from which the seed has fallen pass through the shaker and out the 

 open end down a chute to the furnace room. 



The capacity of this plant is 108 bushels of cones, or about 40 to 

 45 pounds of seed, per day. 



T ewtvporary type. — Where there is only a relatively small quantity 

 of cones, resort is often had to temporary plants which are handled 

 by less experienced men with simple appliances. The first essential 

 in such cases is some sort of shelter which will protect the cones 

 from weather and be sufficiently tight so that the temperature can 

 be raised to at least 110° F. An empty room in a cabin may serve 

 the purpose and often makes as satisfactory a substitute for a regular 

 kiln as can be obtained. It must have tight walls and plenty of space 



