Seasoning of Wood Part 3

=32. Black Pine= (_Pinus murryana_) (Lodge-pole Pine, Tamarack).

Small-sized tree. Rocky Mountains and Pacific regions.

=33. Jersey Pine= (_Pinus inops_ var. _Virginiana_) (Scrub Pine).

Small-sized tree. Along the coast from New York to Georgia and along the mountains to Kentucky.

=34. Gray Pine= (_Pinus divaricata_ var. _banksiana_) (Scrub Pine, Jack Pine). Medium- to large-sized tree. Heartwood pale brown, rarely yellow; sapwood nearly white. Wood light, soft, not strong, close-grained. Used for fuel, railway ties, and fence posts. In days gone by the Indians preferred this species for frames of canoes.

Maine, Vermont, and Michigan to Minnesota.

REDWOOD (See Cedar)

SPRUCE

Resembles soft pine, is light, very soft, stiff, moderately strong, less resinous than pine; has no distinct heartwood, and is of whitish color. Used like soft pine, but also employed as resonance wood in musical instruments and preferred for paper pulp. Spruces, like pines, form extensive forests. They are more frugal, thrive on thinner soils, and bear more shade, but usually require a more humid climate. "Black"

and "White" spruce as applied by lumbermen usually refer to narrow and wide-ringed forms of black spruce (_Picea nigra_).

=35. Black Spruce= (_Picea nigra_ var. _mariana_). Medium-sized tree, forms extensive forests in northwestern United States and in British America; occurs scattered or in groves, especially in low lands throughout the northern pineries. Important lumber tree in eastern United States. Heartwood pale, often with reddish tinge; sapwood pure white. Wood light, soft, not strong. Chiefly used for manufacture of paper pulp, and great quant.i.ties of this as well as _Picea alba_ are used for this purpose. Used also for sounding boards for pianos, violins, etc. Maine to Minnesota, British America, and in the Alleghanies to North Carolina.

=36. White Spruce= (_Picea canadensis_ var. _alba_). Medium- to large-sized tree. Heartwood light yellow; sapwood nearly white.

Generally a.s.sociated with the preceding. Most abundant along streams and lakes, grows largest in Montana and forms the most important tree of the sub-arctic forest of British America. Used largely for floors, joists, doors, sashes, mouldings, and panel work, rapidly superceding _Pinus strobus_ for building purposes. It is very similar to Norway pine, excels it in toughness, is rather less durable and dense, and more liable to warp in seasoning. Northern United States from Maine to Minnesota, also from Montana to Pacific, British America.

=37. White Spruce= (_Picea engelmanni_). Medium- to large-sized tree, forming extensive forests at elevations from 5,000 to 10,000 feet above sea level; resembles the preceding, but occupies a different station. A very important timber tree in the central and southern parts of the Rocky Mountains. Rocky Mountains from Mexico to Montana.

=38. Tide-Land Spruce= (_Picea sitchensis_) (Sitka Spruce). A large-sized tree, forming an extensive coast-belt forest. Used extensively for all cla.s.ses of cooperage and woodenware on the Pacific Coast. Along the sea-coast from Alaska to central California.

=39. Red Spruce= (_Picea rubens_). Medium-sized tree, generally a.s.sociated with _Picea nigra_ and occurs scattered throughout the northern pineries. Heartwood reddish; sapwood lighter color, straight-grained, compact structure. Wood light, soft, not strong, elastic, resonant, not durable when exposed. Used for flooring, carpentry, s.h.i.+pbuilding, piles, posts, railway ties, paddles, oars, sounding boards, paper pulp, and musical instruments. Montana to Pacific, British America.

b.a.s.t.a.r.d SPRUCE

Spruce or fir in name, but resembling hard pine or larch in appearance, quality and uses of its wood.

=40. Douglas Spruce= (_Pseudotsuga douglasii_) (Yellow Fir, Red Fir, Oregon Pine). One of the most important trees of the western United States; grows very large in the Pacific States, to fair size in all parts of the mountains, in Colorado up to about 10,000 feet above sea level; forms extensive forests, often of pure growth, it is really neither a pine nor a fir. Wood very variable, usually coa.r.s.e-grained and heavy, with very p.r.o.nounced summer-wood. Hard and strong ("red"

fir), but often fine-grained and light ("yellow" fir). It is the chief tree of Was.h.i.+ngton and Oregon, and most abundant and most valuable in British Columbia, where it attains its greatest size. From the plains to the Pacific Ocean, and from Mexico to British Columbia.

=41. Red Fir= (_Pseudotsuga taxifolia_) (Oregon Pine, Puget Sound Pine, Yellow Fir, Douglas Spruce, Red Pine). Heartwood light red or yellow in color, sapwood narrow, nearly white, comparatively free from resins, variable annual rings. Wood usually hard, strong, difficult to work, durable, splinters easily. Used for heavy construction, dimension timber, railway ties, doors, blinds, interior finish, piles, etc. One of the most important of Western trees. From the plains to the Pacific Ocean, and from Mexico to British America.

TAMARACK (See Larch)

YEW

Wood heavy, hard, extremely stiff and strong, of fine texture with a pale yellow sapwood, and an orange-red heartwood; seasons well and is quite durable. Extensively used for archery bows, turner's ware, etc.

The yews form no forests, but occur scattered with other conifers.

=42. Yew= (_Taxus brevifolia_). A small to medium-sized tree of the Pacific region.

SECTION III

BROAD-LEAVED TREES

WOOD OF BROAD-LEAVED TREES

[Ill.u.s.tration: Fig. 4. Block of Oak. CS, cross-section; RS, radial section; TS, tangential section; _mr_, medullary or pith ray; _a_, height; _b_, width; and _e_, length of pith ray.]

[Ill.u.s.tration: Fig. 5. Board of Oak. CS, cross-section; RS, radial section; TS, tangential section; _v_, vessels or pores, cut through.; A, slight curve in log which appears in section as an islet.]

[Ill.u.s.tration: Fig. 6. Cross-section of Oak (Magnified about 5 times).]

On a cross-section of oak, the same arrangement of pith and bark, of sapwood and heartwood, and the same disposition of the wood in well-defined concentric or annual rings occur, but the rings are marked by lines or rows of conspicuous pores or openings, which occupy the greater part of the spring-wood for each ring (see Fig. 4, also 6), and are, in fact the hollows of vessels through which the cut has been made. On the radial section or quarter-sawn board the several layers appear as so many stripes (see Fig. 5); on the tangential section or "b.a.s.t.a.r.d" face patterns similar to those mentioned for pine wood are observed. But while the patterns in hard pine are marked by the darker summer-wood, and are composed of plain, alternating stripes of darker and lighter wood, the figures in oak (and other broad-leaved woods) are due chiefly to the vessels, those of the spring-wood in oak being the most conspicuous (see Fig. 5). So that in an oak table, the darker, shaded parts are the spring-wood, the lighter unicolored parts the summer-wood. On closer examination of the smooth cross-section of oak, the spring-wood part of the ring is found to be formed in great part of pores; large, round, or oval openings made by the cut through long vessels. These are separated by a grayish and quite porous tissue (see Fig. 6, A), which continues here and there in the form of radial, often branched, patches (not the pith rays) into and through the summer-wood to the spring-wood of the next ring. The large vessels of the spring-wood, occupying six to ten per cent of the volume of a log in very good oak, and twenty-five per cent or more in inferior and narrow-ringed timber, are a very important feature, since it is evident that the greater their share in the volume, the lighter and weaker the wood. They are smallest near the pith, and grow wider outward. They are wider in the stem than limb, and seem to be of indefinite length, forming open channels, in some cases probably as long as the tree itself. Scattered through the radiating gray patches of porous wood are vessels similar to those of the spring-wood, but decidedly smaller. These vessels are usually fewer and larger near the outer portions of the ring. Their number and size can be utilized to distinguish the oaks cla.s.sed as white oaks from those cla.s.sed as black and red oaks. They are fewer and larger in red oaks, smaller but much more numerous in white oaks. The summer-wood, except for these radial, grayish patches, is dark colored and firm. This firm portion, divided into bodies or strands by these patches of porous wood, and also by fine, wavy, concentric lines of short, thin-walled cells (see Fig. 6, A), consists of thin-walled fibres (see Fig. 7, B), and is the chief element of strength in oak wood. In good white oak it forms one-half or more of the wood, if it cuts like horn, and the cut surface is s.h.i.+ny, and of a deep chocolate brown color. In very narrow-ringed wood and in inferior red oak it is usually much reduced in quant.i.ty as well as quality. The pith rays of the oak, unlike those of the coniferous woods, are at least in part very large and conspicuous. (See Fig. 4; their height indicated by the letter _a_, and their width by the letter _b_.) The large medullary rays of oak are often twenty and more cells wide, and several hundred cell rows in height, which amount commonly to one or more inches. These large rays are conspicuous on all sections. They appear as long, sharp, grayish lines on the cross-sections; as short, thick lines, tapering at each end, on the tangential or "b.a.s.t.a.r.d" face, and as broad, s.h.i.+ny bands, "the mirrors," on the radial section. In addition to these coa.r.s.e rays, there is also a large number of small pith rays, which can be seen only when magnified. On the whole, the pith rays form a much larger part of the wood than might be supposed. In specimens of good white oak it has been found that they form about sixteen to twenty-five per cent of the wood.

[Ill.u.s.tration: Fig. 7. Portion of the Firm Bodies of Fibres with Two Cells of a Small Pith Ray _mr_ (Highly Magnified).]

[Ill.u.s.tration: Fig. 8. Isolated Fibres and Cells, _a_, four cells of wood, parenchyma; _b_, two cells from a pith ray; _c_, a single joint or cell of a vessel, the openings _x_ leading into its upper and lower neighbors; _d_, tracheid; _e_, wood fibre proper.]

Minute Structure

[Ill.u.s.tration: Fig. 9. Cross-section of Ba.s.swood (Magnified).

_v_, vessels; _mr_, pith rays.]

If a well-smoothed thin disk or cross-section of oak (say one-sixteenth inch thick) is held up to the light, it looks very much like a sieve, the pores or vessels appearing as clean-cut holes. The spring-wood and gray patches are seen to be quite porous, but the firm bodies of fibres between them are dense and opaque. Examined with a magnifier it will be noticed that there is no such regularity of arrangement in straight rows as is conspicuous in pine. On the contrary, great irregularity prevails. At the same time, while the pores are as large as pin holes, the cells of the denser wood, unlike those of pine wood, are too small to be distinguished. Studied with the microscope, each vessel is found to be a vertical row of a great number of short, wide tubes, joined end to end (see Fig. 8, _c_). The porous spring-wood and radial gray tracts are partly composed of smaller vessels, but chiefly of tracheids, like those of pine, and of shorter cells, the "wood parenchyma," resembling the cells of the medullary rays. These latter, as well as the fine concentric lines mentioned as occurring in the summer-wood, are composed entirely of short tube-like parenchyma cells, with square or oblique ends (see Fig. 8, _a_ and _b_). The wood fibres proper, which form the dark, firm bodies referred to, are very fine, thread-like cells, one twenty-fifth to one-tenth inch long, with a wall commonly so thick that scarcely any empty internal s.p.a.ce or lumen remains (see Figs. 8, _e_, and 7, B). If, instead of oak, a piece of poplar or ba.s.swood (see Fig. 9) had been used in this study, the structure would have been found to be quite different. The same kinds of cell-elements, vessels, etc., are, to be sure, present, but their combination and arrangement are different, and thus from the great variety of possible combinations results the great variety of structure and, in consequence, of the qualities which distinguish the wood of broad-leaved trees. The sharp distinction of sap wood and heartwood is wanting; the rings are not so clearly defined; the vessels of the wood are small, very numerous, and rather evenly scattered through the wood of the annual rings, so that the distinction of the ring almost vanishes and the medullary or pith rays in poplar can be seen, without being magnified, only on the radial section.

LIST OF MOST IMPORTANT BROAD-LEAVED TREES (HARDWOODS)

Woods of complex and very variable structure, and therefore differing widely in quality, behavior, and consequently in applicability to the arts.

AILANTHUS

=1. Ailanthus= (_Ailanthus glandulosa_). Medium to large-sized tree.

Wood pale yellow, hard, fine-grained, and satiny. This species originally came from China, where it is known as the Tree of "Heaven,"

was introduced into the United States and planted near Philadelphia during the 18th century, and is more ornamental than useful. It is used to some extent in cabinet work. Western Pennsylvania and Long Island, New York.

ASH

Wood heavy, hard, stiff, quite tough, not durable in contact with the soil, straight-grained, rough on the split surfaces and coa.r.s.e in texture. The wood shrinks moderately, seasons with little injury, stands well, and takes a good polish. In carpentry, ash is used for stairways, panels, etc. It is used in s.h.i.+pbuilding, in the construction of cars, wagons, etc., in the manufacture of all kinds of farm implements, machinery, and especially of all kinds of furniture; for cooperage, baskets, oars, tool handles, hoops, etc., etc. The trees of the several species of ash are rapid growers, of small to medium height with stout trunks. They form no forests, but occur scattered in almost all our broad-leaved forests.

=2. White Ash= (_Fraxinus Americana_). Medium-, sometimes large-sized tree. Heartwood reddish brown, usually mottled; sapwood lighter color, nearly white. Wood heavy, hard, tough, elastic, coa.r.s.e-grained, compact structure. Annual rings clearly marked by large open pores, not durable in contact with the soil, is straight-grained, and the best material for oars, etc. Used for agricultural implements, tool handles, automobile (rim boards), vehicle bodies and parts, baseball bats, interior finish, cabinet work, etc., etc. Basin of the Ohio, but found from Maine to Minnesota and Texas.

=3. Red Ash= (_Fraxinus p.u.b.escens_ var. _Pennsylvanica_). Medium-sized tree, a timber very similar to, but smaller than _Fraxinus Americana_.

Heartwood light brown, sapwood lighter color. Wood heavy, hard, strong, and coa.r.s.e-grained. Ranges from New Brunswick to Florida, and westward to Dakota, Nebraska, and Kansas.