Wood and Forest Part 2

1902, p. 265. A. D. Hopkins, _Some of the Princ.i.p.al Insect Enemies of Coniferous Forests in the United States_.

1902, p. 309. Overton, W. Price, _Influence of Forestry on the Lumber Supply_.

1903, p. 279. James W. Toumey, _The Relation of Forests to Stream Flow_.

1903, p. 313. A. D. Hopkins, _Insect Injuries to Hardwood Forest Trees_.

1904, p. 133. E. A. Sterling, _The Att.i.tude of Lumbermen toward Forest Fires_.

1904, p. 381. A. D. Hopkins, _Insect Injuries to Forest Products_.

1905, p. 455. Henry Grinell, _Prolonging the Life of Telephone Poles_.

1905, p. 483. J. Grivin Peters, _Waste in Logging Southern Yellow Pine_.

1905, p. 636. Quincy R. Craft, _Progress of Forestry in 1905_.

1907, p 277. Raphael Zon and E. H. Clapp, _Cutting Timber in the National Forests_.

U. S. Department of Agriculture, Division of Entomology Bulletins:

No. 11. n. s. L. O. Howard, _The Gypsy Moth in America_.

No. 28. A. D. Hopkins, _Insect Enemies of the Spruce in the Northeast_.

No. 32. n. s. A. D. Hopkins, _Insect Enemies of the Pine in the Black Hills Forest Reserve_.

No. 48. A. D. Hopkins, _Catalog of Exhibits of Insect Enemies of Forest and Forest Products at the Louisiana Purchase Exposition, St. Louis, Mo._, 1904.

No. 56. A. D. Hopkins, _The Black Hills Beetle_.

No. 58. Part 1, A. D. Hopkins, _The Locust Borer_.

No. 58. Part II, J. L. Webb, _The Western Pine Destroying Bark Beetle_.

U. S. Department of Agriculture, Bureau of Plant Industry, Bulletins:

No. 32. Herman von Schrenck, _A Disease of the White Ash Caused by Polyporus Fraxinophilus_, 1903.

No. 36. Hermann von Schrenck, _The "Bluing" and "Red Rot" of the Western Yellow Pine_, 1903.

_Report of the Commissioner of Corporations on the Lumber Industry_, Part I, _Standing Timber_, February, 1911. The latest and most reliable investigation into the amount and owners.h.i.+p of the forests of the United States.

Ward, H. Marshall, _Timber and some of its Diseases_.

London: Macmillan & Co., 295 pp. An English book that needs supplementing by information on American wood diseases, such as is included in the list of government publications given herewith. The book includes a description of the character, structure, properties, varieties, and cla.s.sification of timbers.

CHAPTER I.

THE STRUCTURE OF WOOD.

When it is remembered that the suitability of wood for a particular purpose depends most of all upon its internal structure, it is plain that the woodworker should know the essential characteristics of that structure. While his main interest in wood is as lumber, dead material to be used in woodworking, he can properly understand its structure only by knowing something of it as a live, growing organism. To facilitate this, a knowledge of its position in the plant world is helpful.

All the useful woods are to be found in the highest sub-kingdom of the plant world, the flowering plants or Phanerogamia of the botanist.

These flowering plants are to be cla.s.sified as follows:

{ I. Gymnosperms. (Naked seeds.) { 1. Cycadaceae. (Palms, ferns, etc.) { 2. Gnetaceae. (Joint firs.) { 3. Conifers. Pines, firs, etc.

Phanerogamia, { II. Angiosperms. (Fruits.) (Flowering plants) { 1. Monocotyledons. (One seed-leaf.) { (Palms, bamboos, gra.s.ses, etc.) { 2. Dicotyledons. (Two seed-leaves.) { a. Herbs.

{ b. Broad-leaved trees.

Under the division of naked-seeded plants (gymnosperms), practically the only valuable timber-bearing plants are the needle-leaved trees or the conifers, including such trees as the pines, cedars, spruces, firs, etc. Their wood grows rapidly in concentric annual rings, like that of the broad-leaved trees; is easily worked, and is more widely used than the wood of any other cla.s.s of trees.

Of fruit-bearing trees (angiosperms), there are two cla.s.ses, those that have one seed-leaf as they germinate, and those that have two seed-leaves.

The one seed-leaf plants (monocotyledons) include the gra.s.ses, lilies, bananas, palms, etc. Of these there are only a few that reach the dimensions of trees. They are strikingly distinguished by the structure of their stems. They have no cambium layer and no distinct bark and pith; they have unbranched stems, which as a rule do not increase in diameter after the first stages of growth, but grow only terminally. Instead of having concentric annual rings and thus growing larger year by year, the woody tissue grows here and there thru the stem, but mostly crowded together toward the outer surfaces. Even where there is radial growth, as in yucca, the structure is not in annual rings, but irregular. These one seed-leaf trees (monocotyledons) are not of much economic value as lumber, being used chiefly "in the round," and to some extent for veneers and inlays; _e.g._, cocoanut-palm and porcupine wood are so used.

The most useful of the monocotyledons, or endogens, ("inside growers,"

as they are sometimes called,) are the bamboos, which are giant members of the group of gra.s.ses, Fig. 1. They grow in dense forests, some varieties often 70 feet high and 6 inches in diameter, shooting up their entire height in a single season. Bamboo is very highly valued in the Orient, where it is used for masts, for house rafters, and other building purposes, for gutters and water-pipes and in countless other ways. It is twice as strong as any of our woods.

Under the fruit-bearing trees (angiosperms), timber trees are chiefly found among those that have two seed-leaves (the dicotyledons) and include the great ma.s.s of broad-leaved or deciduous trees such as chestnut, oak, ash and maple. It is to these and to the conifers that our princ.i.p.al attention will be given, since they const.i.tute the bulk of the wood in common use.

The timber-bearing trees, then, are the:

(1) Conifers, the needle-leaved, naked-seeded trees, such as pine, cedar, etc. Fig. 45, p. 199.

(2) Endogens, which have one seed-leaf, such as bamboos, Fig. 1.

(3) Broad-leaved trees, having two seed-leaves, such as oak, beech, and elm. Fig. 48, p. 202.

The common cla.s.sifications of trees are quite inaccurate. Many of the so-called deciduous (Latin, _deciduus_, falling off) trees are evergreen, such as holly, and, in the south, live oak, magnolia and cherry. So, too, some of the alleged "evergreens," like bald cypress and tamarack, shed their leaves annually.

[Ill.u.s.tration: Fig. 1. A Bamboo Grove, Kioto, j.a.pan.]

Not all of the "conifers" bear cones. For example, the juniper bears a berry. The ginko, Fig. 2, tho cla.s.sed among the "conifers," the "evergreens," and the "needle-leaf" trees, bears no cones, has broad leaves and is deciduous. It has an especial interest as being the sole survivor of many species which grew abundantly in the carboniferous age.

[Ill.u.s.tration: Fig. 2. Ginko Leaf.]

Also, the terms used by lumbermen, "hard woods" for broad-leaved trees and "soft woods" for conifers, are still less exact, for the wood of some broad-leaved trees, as ba.s.s and poplar, is much softer than that of some conifers, as Georgia pine and lignum vitae.

Another cla.s.sification commonly made is that of "endogens" (inside growers) including bamboos, palms, etc., and exogens (outside growers) which would include both conifers and broad-leaved trees.

One reason why so many cla.s.sifications have come into use is that none of them is quite accurate. A better one will be explained later. See p. 23.

As in the study of all woods three sections are made, it is well at the outset to understand clearly what these are.

The sections of a tree made for its study are (Fig. 3):