Innnfi'j 



ISforth American Walnut Woods If 





ASSISTANT DENDItOlJ 



PAET TWO 

 Editor's Note 



This article Is run with the realization that it Is essentially technical but in the belief that with the rapidly 

 inrreasins use of black walnut, it is necessary that there be authentic knowledge of those woods which may be 

 offered in place of It. 



Black Walnut 



The black walnut (Jnglans nigra Linnaeus) (Plate II.) grows from 

 southern Ontario to Plorida, central Alabama and Mississippi, and 

 westward through southern Michigan, Wisconsin and Minnesota, to 

 Nebraska, Kansas, and Texas (San Antonio river). 

 Uses 



A complete list of the 

 past and present uses should 

 include nearly every article 

 made of wood. Black wal- 

 nut is used in making coun- 

 ter tops, railing, and in- 

 terior finishing, gun stocks, 

 picture and stereoscope 

 frames, cofEns, switchboards, 

 shingles, building material 

 of all kinds, cross-ties, and 

 naves for ■ wheels. The 

 quality of the wood makes 

 it also suited especially for 

 carving and ornamental 

 work. Old stumps, knots, 

 limbs and short, crooked 

 logs, when worked up into 

 veneer, have great value on 

 account of the beautiful 

 grain in these parts. 



Beforo oak came into 

 such general use the wood 

 of black walnut was em- 

 ployed more extensively for 

 cabinet work and interior 

 finish more than any other 

 American wood. For dura- 

 bility in contact with the 

 soil the heartwood was used 

 frequently for posts, and in 

 regions difficult of access it 

 was employed almost exclu- 

 sively for fence material 

 and farm timber generally, 

 until later when it became 

 too valuable as a cabinet 1 IG 1 FI 



and veneer wood to be used 



for these purposes. It was used originally in the Middle West for 

 ' ' dug-outs, ' ' where it was not unusual to see a number of these, 

 principally on the Wabash, from thirty to forty feet long and from 

 twenty-three to thirty inches wide. 



The boom in the United States for black walnut ran its course, 

 and when it ceased considerable stock remained in the hands of 

 the millmen. Larger dealers immediately developed a market in 

 Europe, and since then the best walnut logs have been going abroad 

 to meet increasing demands there, whUe the poorer grades only 

 are sold in this country for a few spe(fial uses. Vigorous adver- 

 tising greatly extended the use of black walnut in England, Ger- 

 many, and France, where its good qualities secured permanent custom- 

 ers among manufacturers of furniture and interior finishing ma- 

 *^'''^1- -Oross Characters 



The nearly white sapwood varies in width from ten to twenty 

 rings of annual growth, being much thinner in old than in young 



trees. The heartwood is commonly a rich chocolate-brown, which 

 darkens with age, and sometimes has a violet tinge. It is heavy, 

 its specific gravity when air-dried being .54, and its weight per 

 cubic foot approximately thirty-nine pounds. Black walnut wood 

 is hard (comparing favorably with oak), tough, strong, rather 

 coarse-grained, easily 

 worked, takes high polish, 

 is very durable in contact 

 with the soil, and seldom 

 attacked by borers. It 

 shrinks- very little in sea- 

 soning (about five per 

 cent), but unless carefully 

 dried it warps and checks. 



The diameter of trees 

 vary generally from twelve 

 to thirty inches, and oc- 

 casionally reach from four 

 to six feet, the symmet- 

 rical trunks often being 

 clear of limbs for sixty 

 feet. The heights vary 

 from eighty to one hun- 

 dred feet or more, accord- 

 ing to the density of the 

 forest. The best timber is 

 grown in rich bottom lands. 

 MiNDTE Characters 

 Vessels (Plate II, v.), 

 which may be seen with a 

 pocket lens magnifying 

 from four to six diameters, 

 vary from .40 to .163 milli- 

 meter in diameter, with an 

 average of .100 millimeter 

 (Table I). They are more 

 or less numerous and gen- 

 erally occur singly or in 

 short radial rows of from 

 two to five pores each. 

 They are more or less ir- 

 regular in outline and fre- 

 q u e n 1 1 y much flattened 

 radially, particularly those 

 near the outer boundary of au annual ring of growth (Plate Tl. a. '•.). 

 The walls are very thin and are marked by numerous small bordered 

 pits (Fig. 1, i-p.), which are arranged in horizontal rows wherever 

 the vessels are in contact with wood-parenchyma and pith-ray cells. 

 The length of the vessel segments varies from one to four times the 

 diameter of the vessel. The partition walls (Fig. 1, p. w.) are com- 

 pletely absorbed, leaving the ends of the segments open. 



Wood fibers (Plate II, w. f.) vary from .8642 to 1.772 millimeters in 

 length, with an average length of 1.223 millimeters (Table II), which 

 is greater than that of the other native walnut woods. The wood 

 fibers are arranged chiefly in regular radial rows between the pith-rays. 

 They have rather thick walls and, as a result, small cell cavities, while 

 in the last four or five rows of wood fibers (formed at the end of the 

 growing season) the cell cavities are almost entirely obscured. The 

 simple pits are oblique, slit-like openings in the cell walls, arranged 

 in a single row and chiefly on the radial wall of the fibers (Fig. 2, s. p.). 



—25— 



FIG. 3. 



