UTILIZATION OF ASH. 



15 



containing ash by clearing for agriculture, or, on the other, the 

 possible influence of forest management in increasing the per acre 

 growth of ash, factors which might be considered, to some extent 

 at least, as counterbalancing each other. 



CHARACTERISTICS OF ASH WOOD. 



GENERAL DESCRIPTION OF THE WOOD. 



A.sh wood is heavy, strong, tough, stiff, and hard and takes a high 

 polish. It shrinks only moderately in seasoning and bends well 

 when seasoned. The layers of annual growth are clearly marked by 

 several rows of large, open ducts occupying (in slow-growing speci- 

 mens) nearly the entire width of the annual ring. The medullary 

 rays are numerous and obscure. The color of the heartwood is 

 brown ; the sap wood is much lighter, often nearly wdiite. 



The proportion of heartwood and sapwood varies chiefly with 

 the age of the tree. Old-growth ash trees, over 150 years in age, 

 have a narrow rim of sap, usually less than 2 inches wdde, and in 

 black ash often less than 1 inch. (See PL VIII.) In second-growth 

 ash less than 100 years in age the width of the sap, on trees over 

 12 inches in diameter, is usuallj^ from 3 to 6 inches, and forms by 

 far the greater part of the lumber cut. Black-ash lumber, which 

 usually is cut from very old, slow-growdng trees, is mostly dark- 

 colored heartwood, and the lumber for this reason is known com- 

 mercially as brown ash. Over half of the white-ash and nearly all 

 of the green-ash lumber is cut from trees less than 100 or 150 years 

 in age and is mostly of the lighter color characteristic of sapwood. 



Lumber from rapid-growing second-growth white and green ash 

 is rather coarse grained and not especially attractive in figure. Lum- 

 ber from slow^-growing old growth, especially black ash, is finer 

 grained and handsome in figure. Curly-ash lumber is occasionally 

 cut, usually from black ash, and has an especially handsome figure. 



The fuel value of dry-ash wood is, on the average, 81 per cent as 

 high as hickory and 91 per cent as high as oak. Heavy sticks of 

 a«h frequently will equal oak in fuel value, especially blue, white, 

 and green ash. In general, a cord of ash wood wdll give approxi- 

 mately the same heating value as 1 ton of high-grade coal.^ 



STRUCTURE. 



Ash is a conspicuously ring-porous wood with numerous pores 

 plainly visible to the naked eye in cross section. The structure, as 

 it appears in transverse, radial, and tangential sections, is shown by 

 Plate IV, figures 1, 2, and 3.^ The annual ring is made conspicuous 



1 From figures compiled by H. S. Betts and Ernest Bateman, of the Forest Service. 



2 Photomicrographs of slides made by A. Koehler, of the Forest Products Laboratory. 



