BULLETIN 683, U. S. DEPARTMENT OF AGEICULTUEE. 

 Table 3. — Computed weights of elm in different forms. 





1,000 



feet 



b.m.of 



1-inch 



lumber. 



Cord 



(90 



cubic 



feet 



solid 



wood). 



1,000 board feet of logs. 



Kind of elm. 



Doyle log rule: diameter of logs 

 (iaehes)— 



Scribner log rule: diameter of 

 logs (inches)— 





6 



12 



18 



24 



6 



12 



18 1 24 



White elm, green 



White elm, air-dry. . 

 Slippery elm, green. . 

 Slippery elm, aii'-dry 



Cork elm, green 



Cork elm, air-dry 



Lbs. 



4,300 



2,900 



4,700 



3,200 



4,500 



3,700 



Lbs. 



4,700 



3,200 



5,000 



3,400 



4,900 



4,000 



Lbs. 

 55, 600 

 37, 400 

 59, 900 

 40, 600 

 57, 700 

 48, 100 



Lbs. 

 12,000 



8,100 

 12, 900 



8,800 

 12, 400 

 10,400 



Lbs. 



8,400 



5,600 



9,000 



6,100 



8,700 



7,200 



Lbs. 



7,100 



4,800 



7,600 



5,200 



7,500 



6,100 



Lbs. 

 12, 400 



8, 300 

 13,300 



9,000 

 12,800 

 10,700 



Lbs. 



9,700 



6,500 

 10, 500 



7,100 

 10, 100 



8,400 



Lbs. 



7,700 



5,200 



8,300 



5,600 



8,000 



6,700 



Lbs. 

 7,000 

 4,700 

 7,600 

 5,100 

 7,300 

 6,000 



STRUCTURE OF THE WOOD. 



Elm belongs to the group of ring porous woods, the beginning of 

 each ring or layer of growth containing a band of more or less con- 

 spicuous pores. Throughout the rest of the growth ring there are 

 smaller pores arranged in more or less continuous wavy lines. These 

 wavy lines are of assistance in distinguishing elm from other ring 

 porous -woods, such as the hickories, ashes, oaks, and chestnut. 

 The medullary rays are narrow and not visible to the unaided eye. 

 In hackberry and sugarberry, which resemble the elms in structure, 

 the rays are visible. The number, size, and arrangement of large 

 and small pores serve to distinguish the wood of the different species. 

 Shppery elm (PI. I) has several rows of large pores, and the small 

 pores are in somewhat interrupted wavy lines. In the other species 

 of elm there is a single row of pores at the beginning of each annual 

 ring. In cork ebn (PI. II) these pores are much smaller than in 

 slippery and white elm (PI. Ill), and the small pores are in very 

 distinct, fairly continuous, wavy bands. 



The following key may be used to distinguish the three principal 

 elm species.^ The characteristics mentioned may be seen on a 

 smoothly cut cross section. A hand lens is an efficient aid in applying 

 the key. 



Pores of late wood arranged tangentially in conspicuous wavy, usually continuous, 



bands, the pores minute. 



A. Rays very distinct to the unaided eye; heartwood indistinct, color yellowish. 



Hackberry, Celtis occidentalis. 

 Sugarberry, Celtis mississippiensis . 



B. Rays barely visible to the unaided eye; heartwood distinct, color reddish brown. 



1. Pores of early wood in a band 3 or more pores wide. 



Red or Slippery Elm, UlmtLS pubescens. 



1 Wing elm is similar in appearance to cork elm, except that the bands of small pores are about as 

 vfide as the intervening spaces. Cedar elm may be distinguished by the very indistinct row of pores 

 at the beginning of the annual ring. 



