20 REFORESTATION ON THE NATIONAL FORESTS. 



emphasized, however, that the sun and wind excel any drying house 

 ever constructed. Where artificial drying is necessary the drying 

 house should be roomy and fitted with tiers of trays arranged around 

 the walls from 8 to 10 inches apart (PI. Ill, fig. 2). The trays should 

 be constructed with screen bottoms, with a mesh of suitable size to 

 permit the seed to drop through upon the canvas sheet. After the 

 trays are filled with cones the room is heated to and kept at a tem- 

 perature of from 120 to 140 F. until the cones have opened. Thor- 

 ough ventilation is necessary in order to carry off the moist air. 

 Stirring the cones with an iron rake results in more even drying. 

 As soon as the cones have opened they should be removed and 

 threshed out and a fresh supply put into the trays. A temperature 

 of 140 F. or more, if continued for any length of time, reduces 

 the vitality of the seed. Twelve square feet of tray space will accom- 

 modate a bushel of cones. Soaking the cones of lodgepole pine for 

 a short time before heating them in the drying house aids in the 

 extraction of seed. 



Figure 3 shows the plan of the cone-drying house on the Sno- 

 qualmie National Forest, Washington. This is roughly similar to 

 the prune-drying houses of the Pacific coast, and is designed es- 

 pecially for Douglas fir cones. It has proved very satisfactory, 

 though some slight improvements have been suggested since it has 

 been in operation. One is to insert two or three stove-pipe radiators 

 in the horizontal part of the pipe, in order to utilize the heat more 

 fully. If the width of the floor upon which the trays are handled 

 were increased about 1 foot it would probably add to the convenience 

 in operation. It might be well, also, to make the ventilator, or oblong 

 section, as long as the width of the drying compartment. 



A number of sacks of cones are kept on a rough platform of 

 boards, spaced a few inches apart, near the ceiling of the drying 

 compartment. Cones stored here are dried to a considerable extent 

 before they are placed on the trays. Cones in the lower trays nearest 

 the stove pipe dry most rapidly, and when these are removed the 

 upper trays are dropped down and the empty trays inserted above 

 and filled from the sacks of cones stored overhead. In this way the 

 freshly heated air from the pipe always strikes the driest cones before 

 it has become partly moisture laden, thus insuring that cones which 

 have become partly dried will not have an opportunity to absorb 

 moisture again. 



All the trays of the drying compartment are shaken at intervals of 

 two or three hours, beginning with the top trays and shaking toward 

 the bottom. Probably 75 per cent of the seed is removed from the 

 cones in this way before they are taken from the trays. The floor 

 of the drying compartment is tight and smooth, and all of the seeds 

 are swept together with a floor brush immediately after the trays are 



