LTJMBERIlSrG IN PINE EEGION OF CALIFOBFIA, 85 



yellow pine through a dry kiln on account of the danger from blue 

 stain in ah' drying. A kiln 20 by 100 feet has an average daily 

 capacity of 12,000 feet. Thus at a single-band mill the usual kiln 

 is about 20 by 75 feet or 20 by 100 feet. Under very mifavorable 

 drying conditions such a mill may have a pair of kilns each 20 feet 

 wide and 70 feet long. At a double-band miU, operating two shifts, 

 the dry-kiln plant consists of two kilns each 20 by 100 feet, if drying 

 conditions are favorable. Under less favorable conditions the plant 

 is often double that size. 



Dry kilns may be made of masonry, concrete, wood frame, or wood 

 crib. Masonry and concrete are said to give the best satisfaction. 

 Wood crib is rated as being superior to wood frame construction. 

 The cost of the equipment and fittings for a kihi 20 feet wide and 100 

 feet long, inside measurement, is about $1,600 f. o. b. factory. With 

 a wood crib frame the cost of a kiln of this size in place is from $3,500 

 to $4,000. A kihi 20 by 70 feet with wood frame costs about $2,500 

 in place. A kiln of the same size costs about $10,000 if the material 

 is concrete; and $7,000 if the material is tile. The average cost of 

 kiln drying lumber in this region is usually from 75 to 80 cents per 

 1,000. The cost of handling is approximately 65 cents per 1,000. 



A portion of the upper gi-ades is usually stored in sheds if it is not 

 shipped inunediately after air or kiln drying. The construction of 

 sufficient shed room to accommodate aU upper grades would undoubt- 

 edly be an economy, because such sheds, though they involve an 

 extra handling, do much to prevent deterioration in the quality of the 

 lumber and insure a higher return. Care with wide and thick sugar 

 pine lumber pays especially weU. AU yards in this j-egion suffer 

 from lumber depreciation by waste or change in grades through 

 staining, checking, etc. The amount of this depreciation varies 

 with yard conditions and the care in handhng. It is generally greater 

 in thick lumber than in thiu lumber. Yards with unfavorable climatic 

 and meteorological conditions suffer more heavily than those with 

 good drying conditions. Deterioration takes place in kiln drying and 

 surfacing, as well as in au- drying. Thus shipping tallies at yards 

 differ in amount and quahty from mill tallies of lumber. Jjittle is 

 now known of the amount of deterioration; but studies are being 

 undertaken to determine the amount and extent of depreciation in 

 each grade, under different seasoning conditions and methods. 



Sometimes surfaced lumber is shipped from the larger mills in 

 order to save on freight charges. Hius, in stumpage appraisals it is 

 necessary to add to the sawmill investment enough to cover the cost 

 of a 7)laniiig miU for this purpose, and in computing the cost of 

 lum])fr an allowanwi must be made for this ])luiiii)g. In most 

 instarif^'s llic planing mill is (;los(Jy conn<Hjted witli the box factory 

 and it is difficult to separate the equipment. For a medium-sized 



