356 AMERICAN FOREST TREES 



commercial standpoint, four surpass the others. These are shagbark 

 (Hicoria ovata), shellbark (Hicoria laciniosa), pignut (Hicoria glabra), 

 and mockernut (Hicoria alba). The wood of some of the others is as 

 good, but is scarce; and still others, particularly the pecans, are abun- 

 dant enough, but the wood is inferior. It is impossible in business to 

 separate the hickories. Lumbermen do not do it ; manufacturers cannot 

 do it. In some regions one is more abundant than the others, and conse- 

 quently is used in larger quantities, but in some other region a different 

 species may predominate in the forest and in the factory. It cannot be 

 truthfully asserted that one hickory is always as good as another, or 

 even that a certain species in one region is as good as the same species 

 in another region. All parts of the same tree do not produce wood of 

 equal value. 



Along certain general lines, hickories have many properties in 

 common. The wood is ring-porous, that is, the inner edge of the yearly 

 growth ring has a row of large pores. Others are scattered toward the 

 outer part of the ring, generally decreasing in number and size outward. 

 There is no distinct division between spring and summerwood. The 

 medullary rays are thin and obscure. The unaided eye seldom notices 

 them. The sapwood is white in all species of hickory, and is usually 

 very thick. The heartwood is reddish. Common opinion has long held 

 that sapwood is tougher and more elastic than heartwood, and therefore 

 to be preferred for most purposes. Tests made a few years ago by the 

 United States Forest Service ran counter to the long-established 

 opinion of users, by showing that in most respects the redwood of the 

 heart was as good as the white sapwood. However, where resiliency 

 is the chief requisite, as in slender handles, many manufacturers still 

 prefer sapwood. 



Hickory is very strong, probably the strongest wood in common 

 use in this country. The statement that one wood is stronger than all 

 others is hardly justified because averages of strength should be taken, 

 and not isolated instances. Satisfactory averages have not yet been 

 worked out for a large number of our woods; but, as far as existing figures 

 may be accepted, hickory is at the head of the list for strength.toughness, 

 and resiliency. Choice samples of certain woods may exceed the 

 average of hickory in some of these particulars. Sugar maple, horn- 

 beam, and locust occasionally show greater strength than hickory, but 

 they lack in toughness and resiliency the very properties which give 

 hickory its chief value for many purposes. 



Considerable misunderstanding exists as to second growth hickory. 

 Some suppose it consists of trees of commercial size developed from 

 sprouts where old trees have been cut. That is not generally correct. 



