UTILIZATION OF ELM. 3 
puted weight of 1-inch lumber, the weight of a cord of wood, and the 
weight of logs per thousand board feet as scaled by the Doyle and 
Scribner log rules. In this table the cord is calculated as being 
composed of 90 cubic feet of solid wood. The weight adopted by 
the Hardwood Manufacturers' Association of the United States for 
rough white elm lumber 1 inch thick is 3,200 pounds per thousand 
board feet. Comparison of this with the figures given in Table 3 
shows that the association weight is for lumber in a partially air-dry 
condition. A weight of 3,200 pounds per thousand board feet cor- 
responds to a moisture content of about 16.4 per cent, and air-dry' 
wood usually varies between 12 and 15 per cent. Similarly, the 
weight adopted by the same association for rough cork elm lumber 
is 3,800 pounds per thousand, which is somewhat higher than that 
given in Table 3. 
In general, cork elm has higher strength values than white elm, 
and slippery elm has values between the two. Both white and 
slippery elm have lower strength values than white oak (excepting 
the shock-resisting ability of slippery elm), particularly in com- 
pression perpendicular to grain and hardness. The values for cork 
elm do not vary greatly from those for white oak, except in shock- 
resisting ability, which is much higher in cork elm. The elms all 
rank lower than the hickories in mechanical properties. A good 
quality of cork-elm wood should, however, make a fairly satisfactory 
substitute for hickory where these properties are of first consideration, 
as for long heavy handles, the running-gear parts of light vehicles, 
eveners, etc. 
Elm is a fairly durable wood. The estimated average life of un- 
treated elm lumber in the United States in situations exposed to the 
weather is from 6 to 8 years. The durability of any individual stick, 
however, may vary from this figure, depending on the quality of 
the wood and the moisture conditions. White elm is said to be 
somewhat less durable in contact with the soil than slippery elm. 
It is highly desirable to treat elm where it is to be used in exposed 
situations. By proper treatment with creosote its life may be 
lengthened to 20 or more years. 
Table 1. — Properties of elm woods expressed in comparative terms. 
Property. 
White elm. 
Slippery elm. 
Cork elm. 
Weight 
Rhrinlragfi . 
Moderately heavy 
Moderately heavy 
Heavy. 
Moderate. 
Strength. 
Moderately strong •. 
Moderately stiff. 
Moderately hard 
Good , 
Moderately hard 
Good 
Hard. 
Shock-resisting ability 
Excellent. 
.do 
Poor. 
