THE SAWMILL 



125 



trucks and waggons, 

 veyance takes place. 



Frequently elevated roads traverse the yard on which and below which such con- 



II. Piling. The foundation blocks should be large and should not be subject to rot. Concrete blocks 

 costing 10 cents each are used in the most modern yards. 



Strong, high, horizontal ground sills are of the utmost importance. The front sill should be higher 

 than the middle and back sills, except in shed drying. 



In some yards the front of the piles is given an overhanging " batter," to protect it from rain, an 

 arrangement feasible only in low piles. The usual pitch of the pile is 1 foot in 10 feet. 



The tiers of boards are kept apart by three or four well seasoned cross pieces called "stickers," 

 sawn 1 inch thick, usually. 



White maple, basswood, and buckeye are particularly 

 subject to "stickrot." 



The usual width of the piles is from 6 to 10 feet. 



The distance between the piles is at least 1 foot and 

 should be 3 feet. 



In order to prevent end cracks, the sticking should be 

 placed exactly at the ends or slightly projecting over the ends. 



If the boards are not sawn to exact length, it is wise 

 to have the "overlaps" long. Overlaps of 3 to 6 inches are 

 almost sure to split. Long overlaps are less subject to splitting. 



Each pile must contain equal lengths. Boards of odd 

 lengths (e. g., 1 1 feet long) are placed in the pile containing 

 the next longer even length of board (e.g., 12 feet long). 



Valuable wide boards and heavy planks are often painted 

 at the ends, or "end-cleated." 



Panels of yellow poplar and the best grade of white 

 maple are shed-dried, the boards being placed exactly 

 vertical, without stickers between the tiers. By these means, 

 any pressure of one board against another is prevented. 



Oak, ash, hickory, and elm require at least four months 

 for air drying; lynn, poplar, and pine about two and a half 

 months. 



Slow drying involves danger from sap stain, loss of 

 interest, large yard room, large insurance, and slow filling 

 of orders. Still, in the case of high-grade heavy hardwoods, the immediate and unrestricted use of the 

 dry-kiln is disastrous to green lumber. 



In summer, sappy hardwoods might be put to the dry kiln for a few hours at a low temperature, 

 before being yarded; or they are dipped into or sprinkled with a 5 per cent to 10 per cent solution of 

 (lukewarm) sodium bicarbonate when they come from the saw. 



Thin lumber does not check as badly as thick lumber. Squares check worst of all. 



A fermentation and incidentally a discoloration takes place where two fresh sawn surfaces touch 

 one another. 



Each pile should have a roof 12 inches high in front and 6 inches high in back, projecting in all 

 four directions over the pile. 



Proper curing of lumber is as important as is proper sawing of lumber. 



The largest lumber shed on the Atlantic Coast at the 

 John L. Roper Mill, New Berne, North Carolina. 



III. Dry kiln. A dry kiln consists of:- 



Shed with gates or curtains closing tightly. 

 Lumber conduit. 

 Heating apparatus. 



The heat is supplied either: - 

 By a hot-air fan. 

 Or by a system of steam pipes. 

 Or by steam admitted into drying room. 



