Part 45
The trunk of yellow birch averages a little smaller than that of sweet birch, but may equal it in some instances. Trees reach a height of 100 feet and a diameter of three or four, but a more common size, even in the regions of best development, is a height of sixty or seventy feet, and a diameter of two or less.
Yellow birch was a long time coming into use. One of the first things learned about it by early settlers in the region where it was abundant, was that it decays quickly in situations alternately wet and dry. That prejudiced the woodsmen against it, and they were not disposed to give it a fair trial, as long as there was plenty of other timber. All birches are subject to quick decay, if conditions are right to produce it. Yellow birch in the woods sometimes dies standing, and when that happens, the wood falls to pieces so quickly that the bark may remain standing with very little inside of it except powder of decayed wood. This tree is seldom mentioned in early accounts of lumber operations, and practically never with a good word. Operators generally left it standing when they cut the timber which grew with it.
Yellow birch is heavy, very strong, hard, light brown tinged with red, with thin, nearly white sapwood. The color of the heartwood varies considerably. The pores are very numerous, rather small, and are scattered through the wood with little tendency to run in bands or groups. The springwood blends gradually with the summerwood in a way to make the boundaries of the annual rings somewhat indistinct. Medullary rays are numerous, but very thin and obscure. Quarter-sawing adds little or nothing to the appearance of the wood. It has poor figure, except an occasional tree with wavy or curly grain, or with burls.
The wood may be readily stained. The pores hold the coloring matter applied, and by varying the application, the appearance of the surface can be varied. The colors of mahogany and of cherry are easily imparted, and yellow birch often imitates those woods.
Vehicle makers choose this wood for its strength and elasticity. In the North it is manufactured into frames for cutters and sleighs of all kinds. It is a competitor of sugar maple for that purpose. Hubs are made of it for horse-drawn vehicles, and its hardness gives long wear where the spokes are inserted. That is one of the first points of failure when a soft, inferior wood is used for hubs. The spokes work loose.
Manufacturers of automobiles have tried out yellow birch as material for frames; it has stood the test, and is much used in competition with other woods. The amount demanded for that purpose is not necessarily large, but it must be the best wood that can be had.
This material reaches the markets in all grades. Large amounts are used for packing boxes, crates, and shipping containers. Low grades answer for these purposes, leaving the better sorts for the more exacting industries. The logs are cut in rotary veneer for baskets, and for ply work. Some of the veneer in three-ply is worked into commodities of high class, such as seats and backs of theater chairs.
Birch flooring competes closely with maple for popular favor. It may lack something of maple’s whiteness, but it takes no second place in hardness, smoothness, and wearing qualities. It is made into parquet flooring as well as the ordinary tongued and grooved article. As such, the sap matches the light colored woods, and the heart the dark.
It goes into all kinds of interior house finish, from floor to ceiling, and the finest grades are often devoted to stair work. Door and window frames are made of it in large quantities, but it is not suited to outside work exposed to weather, because of its tendencies to decay. It is much employed as door material. Furniture demands the same class of wood. Medium priced articles may be of solid birch, but the best commodities are made of veneers laid upon other woods. Figured birch is a favorite material for that class of work.
The more common commodities manufactured of this wood can be listed only by groups, because of their great number. Novelties constitute a large class. One of the earliest demands was from the manufacturers of pill boxes, such as apothecaries use. That was before anyone had tried to sell yellow birch in the general market, and the demand came principally from New England and New York. Another early demand came from coopers who found that barrel hoops of yellow birch were highly satisfactory for certain kinds of vessels. Fish kits were among the first to appear in birch hoops. Small saplings were used, not over two inches in diameter. They are large enough to make two hoops by splitting. The bark was left on, and the identity of the wood was never in doubt, because when the sapling is of that size, the bark is a fine yellow. It has not yet commenced to crack open and roll up, as it does later. Millions of birch hoops are still produced yearly in the United States, but all of them are not of this species. The hoop business has existed much more than a century, and millions of young birches have been cut every year to meet the demand.
Birch broom handles have been a commodity since the first lathe went to work on that product. They are made of all the commercial birches, but yellow birch contributes a large part. Other handles are manufactured of it also, such as are fitted to hand saws, planes, drawing knives, chisels, and augers.
[Illustration]
RIVER BIRCH
[Illustration: RIVER BIRCH]
RIVER BIRCH
(_Betula Nigra_)
This tree is known as red birch, river birch, water birch, blue birch, black birch, and simply as birch. The name red birch refers to the color of the bark which is exposed to view in the process of exfoliation. The trunk is constantly getting rid of its outer bark, and in doing so, the exterior layers are rolled back, hang a while, and are gradually whipped off by the wind. The new bark which is exposed to view when the old is rolled back is reddish. Its color varies considerably, sometimes suggesting the tint of old brass, again it is brown, but people in widely separated regions have seen fit to call the tree red birch because of the color of its bark. The name black birch is not appropriate, though the old bark near the base of large trunks may suggest it. No reason can be assigned for calling it blue birch, unless the foliage in early summer may warrant such a term. River birch and water birch are more appropriate, as these names indicate the situations where the species grows. It clings to water courses almost as closely as sycamore. A favorite attitude of the tree is to lean over a river or pond, with the long, graceful limbs almost touching the water.
Nature seems to recognize the tree’s habit of hanging over muddy banks, and has prepared it for that manner of life. Seeds are ripe early in summer when the rivers are falling. They are scattered by myriads on the muddy shores and upon the water. Those which fall in the mud find at once a suitable place for germination, and those whose fortune it is to drop in the water float away with the current or they are driven by the wind until they lodge along the shores, and the receding water leaves them in a few days, and they spring up quickly. Before the autumn or early winter high water comes, they are well rooted in the mud and sand, ready to put up a fight for their lives.
The provision is a wise one. If the seeds matured in the fall, when water is low, they would be strewn along the low shores, and before they could take root and establish themselves, the high water and the ice of winter would destroy them. The seeds need mud to give them a start in life, and they need that start early in summer.
The range of river birch is less extensive than that of the other important eastern birches, yet it is by no means limited. Its eastern boundary is in Massachusetts, its western in Minnesota, and it adheres fairly well to a line drawn between the two states. Its range extends 200 miles west of the Mississippi and covers most of the southern states. It is found in an area of nearly 1,000,000 square miles, but is scarce in most of it. In certain restricted localities it is fairly abundant, but there are thousands of square miles in the limits of its range which have not a single tree. Its greatest development is in the south Atlantic states, and in the lower Mississippi basin.
Trees at their best are from eighty to ninety feet high and from two to four in diameter, but most trunks are less than two feet in diameter. The tree frequently forks fifteen or twenty feet from the ground, or occasionally sends up several stems from the ground. Forms of that kind are practically useless for lumber.
The wood is among the lightest of the birches and weighs 35.91 pounds per cubic foot. It is rather hard, medium strong, the heartwood light brown in color, with thick, pale sapwood. It rates below sweet and yellow birch in stiffness, is very porous, but the pores are quite small, and can scarcely be seen without a magnifying glass. They are diffused throughout the entire annual ring. There is no marked difference in the appearance of the springwood and that of the late season. The medullary rays are very small and have little effect on the appearance of the wood, no matter in what way the sawing is done.
The wood is apt to contain pith flecks and streaks. These are small, brown spots or lines scattered at random through the wood. They are a blemish which is not easily covered up if the wood is to be polished; but they are small and may not be objectionable. The flecks are caused by insects which, early in the season, bore through the bark into the cambium layer (the newly-formed wood), where eggs are deposited. The young insect cuts a tunnel up or down along the cambium layer, an inch or less in length and a sixteenth of an inch wide. This gallery subsequently fills with brown deposits which remain permanently in the wood. Sometimes these deposits are sufficiently hard to turn the edge of tools.
River birch is widely used but in small amounts. It may properly be described as a neighborhood wood--that is, wherever it grows in considerable quantity it is put to use, but nearly always in a local way. For example, in Louisiana, where it is as abundant as in any other state, it is a favorite material for ox yokes, and no report from that state has been made of its employment for any other purpose. The reason given for its extensive use for ox yokes there is that it is very strong for its weight, and that it resists decay. The yokes there are usually left out of doors when not in use, and the dampness and hot weather cause rapid decay of most woods. The birches are usually listed as quick-decaying woods, but the verdict from Louisiana seems to be that river birch is an exception.
Plain furniture is made of it, and the manufacturers of woodenware find it suitable for most of their commodities. It is sometimes listed as wooden shoe material, but no particular instance has been reported where it has been so used in this country. In Maryland some of the manufacturers of peach baskets make bands or hoops of it, and pronounce it as satisfactory for that purpose as elm.
The supply is not in much danger of exhaustion. The species is equipped to take care of itself, occupying as it does, ground not in demand for farming purposes. When a tree once gets a start it has a chance to escape the ax until large enough for use.
WHITE ALASKA BIRCH (_Betula alaskana_) is usually called simply white birch where it grows. It is not exclusively an Alaska species though that is the only place where it touches the territory of the United States. It is supposed by some to be closely related to the white birches of northern Asia, but the relationship, if it exists, has not been established. In Alaska it grows as far north as any timber extends. It was first discovered and reported in 1858 on the Saskatchewan river, east of the Rocky Mountains, and its range is now known to extend down the valley of the Mackenzie river toward the Arctic ocean to a point more than 100 miles north of the Arctic circle. It is common in many parts of Alaska both along the coast and in the interior. In some portions of that territory it is an important source of fuel. Trees are from twenty-five to sixty feet high, and from six to eighteen inches in diameter. The bark is thin and often nearly white, separating into thin scales. The tree bears typical birch cones, but larger than those of some of the other species. No tests of the wood’s physical properties have been made, but it looks like the wood of paper birch, and will probably attain to considerable importance in the future, since it grows over a large area, and in many parts is abundant. There remain many things for both botanists and wood-users to investigate concerning this tree which has a range of more than half a million square miles.
WESTERN BIRCH (_Betula occidentalis_) is believed to be the largest birch in the world, and yet it is not of much commercial importance in the United States, because of scarcity, occurring only in northwestern Washington and in the adjacent parts of British Columbia, as far as its range has been determined. It resembles paper birch, and has often been supposed to be that tree. The people in the restricted region where it grows speak of it simply as birch. The largest trees are 100 feet high and four feet in diameter, clear of limbs forty or fifty feet. A height of seventy feet and a diameter of two are common. The general color of the trunk is orange-brown, the new bark, exposed by exfoliation, is yellow. The tree prefers the border of streams and the shores of lakes. Though it is the largest of the birches, its seeds are among the smallest. They are provided with two wings and are good flyers. Manufacturers of flooring and interior finish in Washington reported the use of 315,000 feet of this birch in 1911. That was the only use found for it in the only state where it grows. Information is meager as to the probable quantity of this birch available. It has been reported in Idaho, but exact information on the subject is lacking.
MOUNTAIN BIRCH (_Betula fontanalis_) is a minor species concerning which there has been much contention among botanists. It has finally been called mountain birch because it grows on mountains, as high as 10,000 feet among the Sierra Nevadas in California. It has many local names for a tree so small as to be almost a shrub throughout most of its range: Black birch, sweet birch, cherry birch, water birch, and canyon birch. Its bark is of the color of old copper; wood is light yellowish-brown, with thick white sapwood; trunks seldom exceed ten inches in diameter and thirty feet high; range extends from northern British Columbia to California, and along the Rocky Mountains to Colorado and possibly further south. The uses of the wood are few.
[Illustration]
PAPER BIRCH
[Illustration: PAPER BIRCH]
PAPER BIRCH
(_Betula Papyrifera_)
This tree is called paper birch because the bark parts in thin sheets like paper. It is known as canoe birch from the fact that Indians and early white explorers and travelers constructed canoes of the bark. The name silver birch is an allusion to the color of the bark; and big white birch is the name used when the purpose is to distinguish it from the white birch with which it is associated in the northeastern part of its range. It grows as far north as Arctic British America, east to Labrador, south to Michigan and Pennsylvania, and west nearly or quite to the base of the Rocky Mountains. This indicated area exceeds 1,000,000 square miles. The quantity of birch of this species in the forests is unknown, but it runs into billions of feet, probably exceeding any other single species of birch. The tree sometimes grows dispersed through forests of other woods, sometimes in nearly pure stands. Persons well acquainted with the species have expressed the opinion that paper birch exists in larger quantities now than at the time when the country was first explored by white men. That can be said of few other species; but probably holds true of lodgepole pine in the West, loblolly pine in the Southeast, and mesquite in the Southwest. Each of these species took advantage of man’s presence and influence to extend its range. Cattle spread the mesquite; the lodgepole pine came up in fire-burned tracts; loblolly pine spread into abandoned fields; and paper birch profited by fires which destroyed large tracts of timber.
The seeds are light, are furnished with wings which sail them long distances through the air, and they are quickly scattered over the burned areas where they spring up. In the contest, they are competitors of aspen. Birch often captures the ground, but does not always do it. Some of the largest stands in the Northeast occupy tracts bared by fire half a century or more ago. When paper birch does not find open tracts, it contents itself with sharing ground with other species. That was the usual manner of its growth in the original forests; but it has been quick to seize opportunities to take full possession.
It does not like shade and, if crowded, one of the first things it does is to rid its lower trunk of all branches. Only limbs remain which are at the top where they receive plenty of light. Therefore, forest-grown paper birches have long, clean trunks, though they are not always straight. The largest trees are seventy feet high and three in diameter, but those fifty feet in height and eighteen inches in diameter are above rather than under the average.
The bark of paper birch has played an important part in American history, story, and poetry. It was the canoe material, the roof, and the utensil in its region. The Indians had brought the art of canoe making to perfection before white men went among them. The bark peels from the trunks in large pieces, and may be separated into thin sheets, which are very tough, strong, and durable. The Indians sewed pieces of bark together, using the long, slender roots of tamarack for thread. The bark was stretched and tied over a frame, the shape of the canoe, and made of northern white cedar, or some other light wood. Holes in the bark, and the partings at the seams, were stopped with resin from balsam fir, wax from balm of Gilead, or resin from pine. The forest supplied all the material needed by the Indian, and a canoe thus made, and large enough to carry 800 or 1,000 pounds, weighed no more than fifty pounds. Frail as it seemed, it was good for long service on rivers and lakes, and could weather storms of no small severity.
White men adopted the bark canoes at once, and learned from Indians how to make them. The daring explorers and venturesome fur traders who threaded every river and navigated every important lake of British America, found the birch canoe equal to every requirement, even to attacking whales in the tidewater of the Arctic ocean. The bark from this birch was used for tents and the roofs of cabins; vessels in which to store or carry food were made of it, as well as beds on which to sleep, and wrapping material for bundles. These uses have now practically ceased; but as sport, recreation, and for the novelty, articles, from canoes to visiting cards, are still made of the bark.
The wood of paper birch is valuable for certain purposes. The trees are largely white sapwood, which is without figure. It is as plain a wood as grows in the forest, but it may be stained. That, however, is seldom done. The heartwood is dark or red, and is made into brush backs and parquet flooring, but the hearts are small, and no large quantity of that wood is used. The largest use of paper birch is for spools, the common kind for thread. Some of larger size are made for use in mills. The sapwood only is accepted by makers of spools. The heart is cut out, and most of it is thrown away or burned under the boilers. The qualities of paper birch which appeal to spool makers are, white color, small liability to warp, and the ease with which it may be cut without dulling the tools. The logs are worked into bars of the various spool sizes, and are carefully seasoned. One of the problems that must be constantly solved is the prevention of sap stain while the bars are seasoning. The wood discolors quickly and deeply.
Tooth picks, shoe pegs, and shoe shanks are other important commodities manufactured from paper birch. It has not yet been satisfactorily converted into lumber, because it is more valuable for spools, tooth picks, pegs, and the like. This wood is frequently listed as a pulpwood, and it is quite generally believed that its use for that purpose is important. This is apparently an error, as the wood is not even mentioned in statistics of pulpwood output in this country.
Paper birch weighs 37.11 pounds per cubic foot, is strong, hard, tough; medullary rays are numerous but very small and obscure; wood is diffuse-porous, and earlywood blends gradually with latewood in the annual rings which are not very distinct.
This is one of the woods which does not threaten to become soon exhausted. A supply for half a century, at present rate of use, is in sight, if no more should grow; but in fifty years new forests, now young, will be large enough to use.
KENAI BIRCH (_Betula kenaica_) is an Alaska species concerning which comparatively little is known, except that its botanical identity and something of its range have been established. Its small size, and the remote regions where it grows, do not necessarily indicate that it can never be important. Scarcity of other woods may give it a place which it does not now occupy. No reports on the properties of the wood have been made. The bark is deep brown in color. Trees are from twenty to thirty feet high and from twelve to eighteen inches in diameter. The trunks are very short. Cones are an inch or less in length and the double winged seeds are very small. The name applied to this species relates to the region where the best developed trees have been found. As far as known, the species is confined to the coast region of Alaska and to adjacent islands from the head of Lynn canal westward. It has been reported on Koyukuk river above the Arctic circle.