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Curly and Wavy Grain in Wood 





It is rarely that a log is found in which the fibers run exactly 

 parallel with the pith go that their course is straight. Farrly straight- 

 grained pieces are common in small sizes, but in large sticks the 

 grain exhibits Tarious deviations from straight to wa^'y, curly, or 

 more intricate ilesigns. Departure from a straight course tends to 



SPLIT SURFACE OF A CABINET WOOD SnOWIXft THE WAVE.S 

 OX RADIAL SECTIOX. NATURAL SIZE 



reduce the value of sawed timljer 

 where strength is essential, inter- 

 feres with splitting, and makes 

 planing difEcult. 



In cabinet work, interior finish, 

 paneling and other uses where 

 beauty of figure or design are 

 the important considerations, ir- 

 regularity of grain enhances the 

 value of wood. 



There are two principal kinds 

 of wavy growth, one in which the 

 waves occur throughout the tree 

 and the other only in certain por- 

 tions, such as near the insertion 

 of large roots or branches, or in 

 crotches. Certain species of trees 

 have wa\'y wood throughout ; in 

 others occasional trees are found 



which show such structure. In such eases no satisfactory explana- 

 tion has been oifered as to the cause of the peculiar arrangement of 

 the fibers and other wood elements. Sometimes the waves are large; 

 again, they may be very small, although in the same specimen there is 

 usually considerable regularity. Wood with small waves i<; said to be 

 curly-grained. 



Wavy growth near the insertion of large limbs or roots is purely 

 local and can be satisfactorily explained. Wlien a tree is young 

 the limbs are small and the roots have not begun to swell much at 

 the rootstock. With increased growth the branches thicken and usually 

 tend to form a more acute angle with the stem or trunk. The treo 

 also becomes more or less swollen or buttressed at the base due to 

 the necessity for firmer support in the ground. This change in form 

 of the branches or roots produces a folding of the bark which may 

 readUy be observed by anyone, especially on trees with smooth bark. 



Just beneath the bark is the cambium layer, a region of soft gen- 

 erative tissue which forms new wood and new bark. It is this layer 

 that is torn when stripping the bark from a growing stem in the 

 spring. The pressure of the bark on the cambium causes the new 

 wood to be moulded to correspond with the corrugations on the inner 

 surface of the bark. Consequently, as folds develop in the bark as 

 a result of a shortening process, the wood is modeled accordingly. 



This change comes about gradually and if a wavy-grained stump 

 is split through the middle, it will be found to be straight-grained in 



ORTIOX OF THE SAME WOOD SHOWX IX THE FIRST ILLUSTRA- 

 TIOX, AFTER BEIXG QUARTER-SAWED. NATURAL SIZE. 



the interior (which was formed when the tree was young), and from 

 moderately to decidedly wavy in the exterior. Usually the waves are 

 in a tangential direction, that is, they run around the tree; but in trees 

 with very hard bark that tends to retain its shape, the folding may 

 he in a radial plane. Wavy grain also occurs in the bend of a 

 crooked tree for the same reason. 



'Wavy grain adds to the beauty of any wood in which it occurs, 

 and in wood otherwise handsome the effect is particularly pleasing. 

 Thus, in mahogany and black cherry the wood cut from the crotch 

 of a tree produces veneers of high value for artistic effects. Old 

 black walnut stumps are highly prized for fancy gun-stocks, and 

 areas long cut-over are sometimes visited in later years and the 

 stumps removed for this purpose. Such wood is usually free from 

 serious decay, but owing to the fact that it seasoned in large pieces 

 is very likely to be checked in unfortunate places. 



Woods in which the waves run in a radial direction, that is, 

 from the middle of a tree outwards, are in English markets termed 

 "hazel," as "hazel spruce" or "hazel oak." In satin-wood 

 (Xaniho:>:yIum from the West Indies and Chloroxylum swietenia from 

 Ceylon) wavy grain is the normal condition and longitudinal sections 

 exiiibit alternate bands of lighter and duller luster, according to 

 the direction in which the fibers are cut. The wood is very hand- 

 some and is extensively used for the backs of brushes. 



Among the native woods it is 

 very common to find wavy grain 

 in buckeye, especially the yellow 

 liuckeye {Aesculus octandra). The 

 undulations are mostly smalL 

 Specimens of redwood {Sequoia 

 sempervirens) are found occa- 

 sionally with very large, regular 

 waves. Such wood must be cut 

 in a radial direction (quarter- 

 sawed) in order to bring out the 

 full effect of the grain. Owing 

 to the varying direction of the 

 fibers, such wood is hard to sur- 

 face without nicking or gouging. 

 An attempt has been made to 

 improve the appearance of ordi- 

 narily plain woods by giving 

 them an artificial wavy grain. 



TANGEXTIAL VIEW OF A PIECE OF REDWOOD SHOWIXG WAVY 

 GROWTH. NATURAL SIZE. 



To accomplish this, pieces of veneer one-eighth inch thick are pressed 

 hydraulically between two slightly undulating iron plates, the undu- 

 lations fitting into one another. When the wood is planed, imitations 

 of mottled or of wavy wood are produced which are very satisfactory 

 as substitutes for the genuine in cheap work. S. J. E. 



