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TIMBER , the See also:term given to See also:wood Cut and shaped for See also:building purposes, or growing wood suitable for such purposes; in See also:English See also:law the See also:tenant for See also:life may not cut such trees (see See also:WASTE). The word appears in many forms in various See also:Teutonic See also:languages, meaning originally material to be used for building purposes; in the See also:case of Ger. zimmer, and Du. limner, both meaning " See also:room," the word has been transferred to the structures made of this material. The See also:root is seen in Gr. &See also:yew, to build, and See also:Lat. domus, See also:house. The wood used in building is obtained from trees of the class known to botanists as exogens, or those trees which grow larger by the addition each See also:year of a layer of new wood on their See also:outer See also:surface. A transverse See also:section of a See also:tree of this class shows it to consist of three distinct parts: the See also:pith or medulla, the wood, made up of See also:annual rings or layers, and the bark: The pith is in the centre of the tree and around it the wood is disposed in approximately concentric rings; that See also:part near the pith is hard and See also:close in See also:grain, and from its position is termed See also:heart-wood. The See also:sap-wood is made up of the outer layers or rings, and these are softer than the heart and generally of more open grain. Each annual See also:ring is made tip of two parts—an inner soft portion See also:light in See also:colour, and a hard, dark-coloured outer portion. The inner portion is formed See also:early in the See also:season and is termed " See also:spring wood," the darker part being called " autumn wood." The medullary rays extend radially from the centre of the tree to the bark at right angles to the grain of the wood, and serve during life to bind the whole together as well as to convey nourishment from one part of the tree to another. The greatest care should be exercised in the selection of trees for See also:felling.- If the tree is too See also:young the proportion of sap-woodis large, and the heart-wood is not so hard as that of a tree of mature See also:age. The wood of an old tree, on the other See also:hand, has lost a See also:great part of its toughness, and is of See also:bad colour, brittle and often predisposed to decay. In Teimnge Tmber. trees that have arrived at a mature age the heart-wood is in its largest proportion and the sap-wood is See also:firm and elastic; and the timber from such trees is of the strongest, toughest and most durable See also:character. The age at which the See also:northern See also:pine and See also:Norway See also:fir arrive at maturity is between seventy and one See also:hundred 'years. The See also:larch, See also:elm and ash should be felled when the trees are between the ages of fifty and one hundred years. The See also:oak should be about one hundred years old when it is cut. The best See also:time of the year for felling timber is in midsummer or midwinter, when the sap of the tree is at See also:rest; it is not desirable to cut timber in the spring or autumn. By some authorities it is considered a See also:good See also:plan to remove the bark in the early spring'and See also:fell the tree in the ensuing See also:winter. As soon as possible after felling, logs should be converted by sawing into See also:scantling sizes, for if the See also:log is See also:left to dry or season, it is liable on shrinking to split. The usual Coaverslon method is to saw a log into planks or boards by of Timber. cutting it into slices longitudinally as shown in fig. 1; this is called See also:bastard sawing, and is the most bastard sawing quarhu- sawing economical method, but, as will be seen in the See also:diagram, the quality of the boards will vary very much, some consisting almost entirely of sap-wood cut at a tangent to the See also:annular rings such as a, b, c, whilst the centre boards contain the heart-wood cut in the best way at right angles across the annual rings as d, e, f. For oak and other hard See also:woods another method of See also:conversion is often adopted, called See also:quarter sawing. The log is first cut into quarters and then sawn diagonally (fig. 2). In oak this develops the beautiful See also:silver grain by cutting longitudinally through the medullary rays. Timber is now generally sawn into marketable sizes in the See also:country of its growth, and shipped as scantling timber. See also:Definitions and sizes are given below of the most usual forms of sawn timber: A log is the See also:trunk of a tree with the bark removed and branches lopped. A balk is a log hewn or sawn to a square section, and varying in See also:size from 11 to 18 in. square. Planks are parallel-sided pieces of timber from 2 to 6 in. thick, 11 or more ins. wide, and from 8 to 21 ft. See also:long. Deals are similar pieces 9 in. wide, and 2 to 4 in. thick. Battens are similar to deals, but not more than 7 in. wide. Pieces of planks, deals and battens under 8 ft. long are called ends. Many of the soft woods, such as, pine and fir, are sold by the See also:standard. The standard of measurement most in use is the St See also:Petersburg standard, which contains 165 cubic ft. or 720 lineal ft. of rI in. by 3 in. A load of sawn or hewn timber contains 5o cub. ft., and a load of unhewn timber 40 cubic ft. A square is a superficial measurement, used chiefly for boarding, and contains too sq. ft. See also:Norwegian timber is stencilled with the shipper's See also:initials in See also:blue letters painted on the ends. See also:Swedish timber is stencilled with red letters or devices, the. inferior qualities in blue. Prussian timber is scribed on the sides near the See also:middle: By scribing is meant that the distinguishing letters are roughly cut in with a See also:gouge. See also:Russian timber is dry-stamped or See also:hammer-branded on the ends. See also:American (See also:Canadian) timber is stencilled in See also:black and See also: Where it is convenient, timber is sometimes treated with a See also:water seasoning process which enables it to be more easily dried. The wood is placed in a See also:running stream and so tied or chained down as to be entirely submerged. The water enters the pores of the wood (which should be placed with the See also:butt end pointing up stream) and dissolves and forces out the sap. After about two See also:weeks in this position it is taken out and stacked in open sheds to be dried in the natural way, or treated by warm air in See also:special See also:chambers: 'Steaming and boiling' are sometimes resorted to as artificial means of seasoning, but not to any great extent, as the timber deteriorates under such treatment, and the cost of the process is in many cases prohibitive. When wood is required to be See also:bent, however, this is often the method that is adopted to soften the material,. so as to allow it to be bent easily. The time allowed in the English See also:government See also:dockyards for the natural process of seasoning for hard woods such as oak is, for pieces 24 in. sq. and upwards, 26 months; from 16 in. to 20 in. sq., 18 months; from 8 in, to 12 in. sq., to months; from 4 in. to 8 in. sq., 6 months. Soft woods are allowed See also:half these periods. When the wood is required in a " dry " See also:state for joiners' work, twice the length of time is given. Planks are allowed from a half to two-thirds of the above time, according to their thickness. Deals with coarse annual rings (i.e. coarse grain) should be rejected for good work, as also should those. with waney or naturally Defects in bevelled edges. The wide annual rings show that the imber. tree was grown too quickly, probably in marshy ground. 'See also:limber with waney edges has a large proportion of sap-wood, and is cut either from a small tree or from the outer portion of a large one, the waney edge being obviously due to irreur larities in the surface of the tree. ' See also:Cup shake " is a natural splitting in the interior of the tree between two of the annular rings. It is supposed to be caused in severe See also:weather by the freezing pf the ascending sap. " Heart shake " is often found in old trees and extends from the pith or heart of the tree towards the circumference. When there are fissures radiating in several directions it is called " See also:star shake." " Upsets " are the result of some crushing force or violent See also:shock to the balk or log. " Foxey " timber is tinged with dull red or yellow stains, indicating incipient decay.
Doatiness," similarly, is a speckled or spotted stain denoting. decay in certain varieties of timber, such as See also:beech and some kinds of oak.
The See also:primary causes of decay in timber are the presence of sap,
exposure to conditions alternately wet and dry, and want of
Decay to efficient See also:ventilation, especially if accompanied by a
Timber warm and moist See also:atmosphere. Timber is most
durable when it is kept quite dry and well ventilated,
but some varieties last an indefinite See also:period when kept continually
under water. When, on the other hand, the wood becomes alter-
nately wet and dry, " wet rot " results. The wood affected shrivels
up and becomes reduced after a time to a See also:fine See also: In this way the disease is spread rapidly, continually eating into the timber, which is first rendered brittle, and then reduced to powder. A strong growth of the fungus gives the See also:appearance of See also:mildew on the wood, and produces an unpleasant musty See also:smell. The spores of the fungus will find a way through See also:brickwork, See also:concrete and similar material, in See also:order to reach woodwork that may be on the other See also:side. Dampness and a close atmosphere are essential to the growth of dry rot, and it is under these conditions that it spreads most quickly, the fungus soon dying when exposed to the fresh air. There will be little danger of the decay of timber used in the construction of See also:ordinary buildings if care has been taken, in the first place, to have it well seasoned, and, in the second, to ensure its being well ventilated when fixed in position. tlon of There are, however, several preservative processes to 7caber. which timber may be subjected when it is to be fixed in positions which favour its decay (see also DRY See also:Roy). In creosoting, which was invented by J. Bethell and patented by him in 1838, the timber is impregnated with oil of See also:tar. This may be done by soaking the wood in the hot oil for several See also:hours, but the better way is to place the seasoned timber in an See also:iron chamber in which a partial vacuum is created by exhausting the air. The See also:creosote is then forced in at a pressure of from too lb to 16o lb to the sq. in., according to the size of the timber. In warm weather the pressure need not be so great as in winter. The whole process only occupies from two to three hours. Soft woods take up from to to to lb' to the cub. ft.; hard woods are not usually treated by this process. Kyan's process, patented in 1832, consists in impregnating the timber with corrosive sublimate which, acting on the, albumen in the wood, converts it into an indeconiposable sub-stance. Boucherie, a Frenchman, originated a See also:system in which the sap is expelled from the timber under pressure, and a strong See also:solution of See also:copper sulphate is then injected at the end of the wood. In Blythe's process the timber is dried, and crude carbolic See also:acid' injected. In See also:Burnett's process a solution of See also:zinc chloride is forced into the pores of the wood: A new process of preserving timber by means of See also:steam See also:heat has been tried and seems to be effectual. The wood is placed in closed chambers and steam admitted at high pressure (200 lb to the sq. in.). The heat and pressure together exert a chemical See also:action upon the sap, which becomes insoluble and itself preserves the wood from decay. Posts that are to be fixed in the ground should have their buried ends either charred or else well tarred. See also:External woodwork may be protected by See also:painting or oiling. The timber used in building is obtained from trees which may be classed under two heads: (I) Coniferous or See also:needle-leaved trees; (2) the non-coniferous or broad-leaved trees. varieties. Coniferous Trees.—This class includes most of the soft woods which furnish timber for the framing and constructional portions of nearly all building work. They are also used for the See also:finishing See also:joinery of the ordinary class of building. The numerous varieties of pine which are used more extensively than any other See also:kind of wood are included in this class. The northern pine (Pinus sylvestris) has a number of other names and may be referred to under any of the following: Scotch fir, red See also:deal, red fir, yellow deal, yellow fir, Baltic pine, Baltic fir. It grows in See also:Sweden, Norway, See also:Russia, See also:Germany and Great See also:Britain, and often gets a name from the See also:port of shipment, such as See also:Memel fir, Dan2ig fir, See also:Riga fir, and so on. The colour of the wood of the different growths of northern pine varies considerably, the See also:general characteristics being a light reddish yellow colour. The annual rings are well defined, each ring consisting of a hard and a soft portion, respectively dark and light in colour. No medullary rays are visible; the wood is straight in the grain, durable, strong and elastic, easy to work, and is used by the See also:carpenter for See also:internal and external constructional work, and by the joiner for his'fittings. Tar, See also:pitch and See also:turpentine are obtained from the wood of this tree, which weighs from 3o to 38 lb per cub. ft. The white fir, or Norway spruce (Abies excelsa), is exported from Russia, Sweden and Norway, where it grows in enormous quantity. It is the tallest and straightest of See also:European firs, growing with a slender trunk to a height of from 8o to too ft. Like the northern pine, it is called by several names, such as " spruce," " white deal," " white wood," " Norway fir." The colour of the cut wood is a very light yellowish or brownish white, the hard parts of the annual rings being of a darker shade. A characteristic feature is the large number of very hard black knots which the wood contains. It is easy to work, but rather inferior in all respects to the northern pine. Its See also:weight per cubic See also:foot averages about 33 lb. The red pine (Pinus resinosa or P. rubra) is also known as " Canadian pine " and " American deal." It grows in the northern parts of See also:North America, where the tree attains a height of 6o or 70 ft. with a See also:diameter of from 12 to 30 in. It weighs about 36 lb to the cubic foot. In See also:Canada it is called " Norway pine " and " red pine " from the colour of the bark. The wood is white, tinged with yellow or red, of fine grain, and See also:works to a smooth lustrous surface remarkably free from knots. The white pine (Pinus strobus) is exported from the northern parts of the United States of America and from Canada. Other names for this timber are " yellow pine " and " See also:Weymouth pine," the last name originating in the fact that the See also:earl of Weymouth first introduced it into See also:England. The tree attains a height of from 150 to 200 ft. with a thickness of trunk at 5 ft. from the bottom of from 5 to to ft. The wood when cut is white or yellowish white, straight in grain and easily worked, but is not so tough, elastic or durable as the northern pine, and therefore is not so suitable for constructional work. For joiners' work, however, it is well adapted, and See also:glue adheres strongly to it, though nails do not hold well. It weighs about 3o lb per cub. ft. The Kauri pine (Dammara australis) is a native of New See also:Zealand. It grows to a height of from 8o to 140 ft., with a straight See also:stem q to 8 ft. in diameter. The wood is a light yellowish brown in colour, fine in grain and of even texture, the annular rings being marked by a darker See also:line. It is strong, elastic and resinous. A cubic foot weighs about 35 to 40 lb. The pitch pine (Pinus rigida) is a native of Canada and is See also:common throughout the United States of America. It is remarkable for the large quantity of See also:resin it contains, the weight of the wood, which is about 48 lb per cub. ft., and the strong red markings of the grain, usually straight but sometimes exhibiting a beautiful figure. Its weight and strength, and the large size of the balks, make it very valuable for heavy constructional works and piling, and its fine figure makes it equally valuable for joinery. Of the larch the best known variety is the European larch (Larix europaea), which grows in See also:Switzerland, See also:Italy, Russia and Germany. The larch frequently attains a height of too ft. but the See also:average height is about 5o ft. and diameter 3 ft. The wood is extremely durable and lasts well where exposed alternately to wet and dry; indeed, the larch is useful for every purpose of building, internal and external. It is the hardest and toughest of the See also:cone-bearing trees and weighs 30 to 40 lb per cub. ft.; it has a straight grain free from many knots; in colour it is of a rather deep yellow or brownish tint, with the hard portions of the annular rings marked in a darker red. The American black larch (Larix pendula) and the American red larch (Larix microcarpa) are native to North America. The latter tree is of comparatively little service. The black larch yields timber of good quality, nearly equal to that of the European tree. The See also:cedar used in building work is really a See also:species of See also:juniper. The Virginian red cedar (Juniperus virginiana) grows in the United States, Canada and the See also:West Indies. The tree produces excellent timber, and is much used for See also:furniture, its strong acrid See also:taste See also:driving away See also:insects. It weighs about 40 lb per cub. ft. The Bermuda cedar (Juniperus bermudiana) is used for internal joinery and is extremely durable. Hard Woods.—The timbers in the second class are obtained from non-coniferous trees, containing no turpentine or resin, and are given the general name of hard woods. Their initial expense and the high cost of working preclude their general use, and they are consequently reserved to a great extent for specially heavy constructional work and ornamental finishing joinery. The oak (Quercus), of which some sixty distinct species are known, grows freely in See also:Europe and America. Several kinds yield valuable timber: in England the two best-known varieties are Quercus pedunculata and Quercus sessiliflora. There is little difference between the quality of the two woods, the variation being in the foliage and See also:fruit. The wood is very hard, tough, with fine See also:regular grain and close texture, the annular rings being distinct and the medullary rays well marked. When it is cut along these rays beautiful markings are revealed, called silver grain. The colour is a light brown, and its weight is about 5o to 56 lb per cub. ft. Oak is very durable either in a dry or a wet situation, or in a position where it will be alternately dry and wet. It is very suitable for constructional and See also:engineering works, and it supplies one of the finest woods for ornamental joinery work. The Durmast oak grows in See also:France and the See also:south of England; it is not so strong, or durable as the English oak. Baltic oak is grown in Norway, Russia and Germany, and is exported from the Baltic ports. Though inferior to the English oak, it is very, straight in the grain and free from knots. See also:Austrian oak is light in colour, and is much usedfor joinery work. White oak comes principally from Canada, under the name of American oak. It is straight in grain but subject to warping, and is not so durable as See also:British oak. The common See also:walnut (Juglans regia) grows in Great Britain. On See also:account of its scarcity it is little used for building purposes, except for ornamental joinery, being more used by the See also:cabinet and furniture maker. A cubic foot weighs about 45 lb. The white walnut (Juglans See also:alba) or See also:hickory is common in North America, and is very tough, hard and elastic. The black walnut (Juglans See also:nigra) is also native to America. It has a fine grain with beautiful figure, and takes a fine See also:polish. It weighs 56 lb per cub. ft. Of the elm (Ulmus) there are five common varieties, the two most cultivated being the rough-leaved elm (Ulmus campestris), which is grown in large quantities in England and North America, and the smooth-leaved wych elm (Ulmus glabra). The colour of the wood is brown; it is hard, heavy, strong and very tough, and when kept either always wet or always dry is durable. Elm is very liable to warp and shake, is porous and usually See also:cross-grained. The piles of old See also:London See also:Bridge were of elm, and after six centuries of See also:immersion were but little decayed. The wood is not much used in building operations. It weighs about 4o lb per cub. ft. The common ash (Fraxinus excelsior) is a native of Europe and Northern See also:Asia, and is grown extensively in Great Britain. Its colour is light brown, sometimes with a greenish tint, with the annular rings of darker colour. The wood is very tough and strop and See also:superior to most wood in See also:elasticity; and it weighs 40 to 55 per cub. ft. Beech (Fagus sylvatica) grows in the temperate districts of Europe. The wood is heavy, strong and hard; white to light reddish-brown in colour; and durable if kept either dry or wet; is porous and works easily; it weighs about 40 to 48 lb per cub. ft. The red' beech (Fagus ferrugina) is common in North America. Sycamore (Ater pseudo-platanus), sometimes mistakenly called the See also:plane tree, is common in Germany and Britain and in the eastern states of North America. It is a large tree of rapid growth. The wood is light brown or yellowish white, with annular rings not very distinct, often cross-grained and of uniformly coarse texture. It warps and cracks rather badly, and weighs from 35 to 42 lb per cub. ft. See also:Teak (Tectona grandis) is a native of See also:southern See also:India and See also:Burma. It grows rapidly to a great height, often exceeding 150 ft., with a straight trunk and spreading branches. Teak wood is straight in the grain and exceptionally strong and durable, its oily nature enabling it to resist the attacks of insects and to preserve, iron nails and fastenings. It weighs from 45 to 56 lb per cub. ft. See also:Mahogany (Swietenia mahogani) is a native of the West Indies and Central America, the best-known varieties being Cuban or See also:Spanish and See also:Honduras. The Spanish wood has a darker colour and richer figure than the Honduras, and is therefore preferred for ornamental joinery work. The colour of mahogany is reddish brown, and in the Cuban wood the pores are often filled with a white chalky substance which is usually absent in the Honduras variety; the latter, however, may be obtained in larger sizes, and is straighter in the grain and easier to work. Spanish mahogany weighs about 56 lb to the cubic ft., and the Honduras variety about 36 lb. G-eenheart (Nectandra rodiaei) is a very heavy, hard and durable wood from the See also:East Indies. It ranges in colour from See also:pale yellow to a deep brown, and the grain is very compact and of close texture. The wood contains an oil which enables it to resist the attack of See also:sea See also:worms, and this quality makes it suitable for use in marine construction. The average weight of a cubic foot is about 61 lb. Basswood (Tilia americana) is common in Canada and in the northern United States. It is soft and easy to work, and of even texture and straight grain. It may be obtained in wide boards, and thus is fitted for use in large panels, It weighs about 3o lb per cub. ft. There are several varieties of See also:maple growing in Canada and the United States, but the one in most common use is the See also:sugar maple, also called See also:rock maple, which grows freely in the districts around the Great Lakes. The wood is fine-grained, frequently with a beautiful wavy figure, yellowish white to light brown in colour; it is very hard, tough and durable. Birds'-eye maple has a See also:peculiar See also:curly grain, and is much in See also:request for ornamental joinery.
The numerous tests of the strength of timber which have been made by various authorities from time to time vary so much, both as regards the conditions under which
they were carried out and the results obtained, that TimTimber.ngth of great discretion is required in using them for any practical purpose. An important See also:series of tests was made in 1883 and 1887 at See also:Munich by See also:Professor Johann Bauschinger. He reduced all the specimens submitted for test to a standard of moisture, the percentage selected being 15 %. This was necessary on account of the great difference in strength found to exist between specimens cut from the same piece of timber but differing in the amount of moisture they contained.
In America, Professor J. B. See also: As in the tests made by Bauschinger, the percentage of moisture contained in the wood was very carefully observed, and it was found that this amount of moisture has a very great See also:influence upon the resisting See also:power of the wood, the strength increasing with the dryness of the material up to 3 or 4% of moisture, at which point the greatest strength of the wood is reached. Wood in such a dry See also:condition, however, is never found in actual practice, timber in an ordinary well-warmed and well-ventilated situation probably containing at least 1o%. One general conclusion arrived at both by Bauschinger and Johnson was that the strength is much affected by the specific gravity of the timber. In all cases the strength increases proportionately with the See also:density of the wood. A most See also:complete series of tests upon the See also:physical characteristics of the hard woods of Western See also:Australia was completed for the government of Western Australia by G. A. See also:Julius in 1907. This work was carried out in a most thorough manner, and as many as 16,000 tests were made, the conditions of test being based upon those laid down by Johnson. The results serve to show the great value of Australian timbers, and the comparisons made with the typical timbers of many other countries emphasize the fact that the Australian woods are equal to any in the See also:world for hardness, strength and durability. For use under special conditions a wood suited to the particular requirements must be selected. The following is a See also:list of the best timbers for different situations: for general construction, spruce and pine of the different varieties; for heavy constructions, pitch pine, oak (preferably of English growth), teak, jarrah; for constructions immersed in water, Baltic pine, elm, oak, teak, jarrah; for very dry situations, spruce, pines, mahogany, teak, See also:birch, sycamore. There are no regulations in England limiting the working stresses that may safely be placed upon timber, although in some districts the least sizes that may be used for timbers in See also:roofs and floors are specified. In some European and other. countries, however, the safe working stresses of timber used for constructional purposes are defined. The building by-See also:laws of the See also:municipality of Johannes-See also:burg, in South See also:Africa, contain the following table: Safe Working Stresses for Timber. In tons per square inch. Material. Tensional. Compressive. Bending. Extreme Fibre Stress. Timber a — — Fir and Pine . I 1 a 1 Hardwood . 2 ~S 5 See also:Note.—The See also:compression stresses are for See also:short struts and columns where the length does not exceed for timber 15 times the least transverse See also:dimension, and where the ends are fixed. Where the ratio of the length to the least transverse dimension is higher, the load per square inch shall be proportionately reduced. No See also:post of timber shall exceed in length 30 times its least transverse dimension. TIMBER-LINE, in physical See also:geography, the line of See also:elevation above sea-level above which trees do not grow. In anyhilly locality, which is not of too high See also:latitude to allow of trees growing near the sea-level, this line is generally clearly marked. It varies not only with general but also with See also:local conditions of climate, just as does the See also:snow-line. TIMBER-See also:WOLF (Canis occidentalis), or See also:grey wolf, an American species, or, perhaps, a See also:geographical See also:race of the European C. See also:lupus (see WoLF). The length of good specimens is about 64 in., of which the tail forms nearly a quarter, and the range of colour is from black to white. See also:Cattle ranchers and shepherds have established a See also:war of extermination against this wolf and the See also:coyote; several states offer bounties ranging from $2 to $10 on wolf-scalps. In See also:Montana in 1901 during a See also:month in the See also:saddle an observer saw no wolves, which have become so scarce that the occupation of the professional wolf-See also:hunter is almost gone. These animals are, however, far from being exterminated, the " bad lands " forming an absolutely secure See also:refuge. Additional information and CommentsThere are no comments yet for this article.
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