8 INTRODUCTION. 



recognized by splitting wagon and cooperage stock in the woods and 

 seasoning it partly shaped, and also in making a distinction, often unnec- 

 essarily, between air-dried and kiln-dried material. 



Where strength is required, the weight of the material will give 

 good indications, for it is now pretty well established that weight and 

 strength go more or less together. But since weight in the green wood 

 is made up of at least three elements, namely, that of the wood fiber 

 itself, that of the water in the cell spaces, and that of the water in the 

 cell walls, the weight is deceptive unless we know also the moisture 

 condition of the stick or else ascertain the specific weight of the dry 

 wood. That the moisture contents influence considerably the strength 

 of the material is now well proven, strength increasing with loss of 

 moisture, and hence in practice allowance should be made according to 

 whether the stick is to be used where it will be exposed to the weather 

 or under cover and painted. 



In some woods like the pines and the "ring porous" woods, such as 

 oak, chestnut, and hickory, in which each annual layer or ring is made 

 up of two distinct parts, the loose, porous spring wood and the dense 

 and firm summer wood, the proportion of the latter per square inch of 

 cross section — usually but not always depending on the width of the 

 ring — furnishes a more direct criterion than the weight alone. The 

 color effect of itself gives indications of the weight, since both weight 

 and color effect depend on the same feature, namely, quantity of mate- 

 rial ; hence the larger quantity of dense summer wood on the cross 

 section occasions darker color, which is usually indicative of strength. 

 Color, too, must be consulted to detect incipient decay. Again, the 

 difference in firmness and hardness of the summer wood itself, as tested 

 by the knife or recognized in the difference of color effect by the prac- 

 ticed eye, furnishes another criterion in the selection of the stick. 



Lastly, the manner in which the stick is sawed from the tree has a 

 remarkable influence upon its qualities and behavior, and it should, 

 therefore, either be specially sawed or selected with a view to its char- 

 acter and to the purpose for which it is to be used. This is a matter 

 fully appreciated among only a few wood users, like the wheelwrights, 

 piano makers, etc., but it needs to be observed much more than it is, 

 even in building. Quarter or rift sawing, i. e., cutting sticks or boards 

 out of the log in such a mauner that the annual rings are cut through 

 as nearly as possible radially, has lately been practiced largely for the 

 sake of the beauty of the even grain thus obtained, and also for floor- 

 ing on account of the better wear which the even exposure of the grain 

 (hard bands of summer wood on edge) secures; but it should be much 

 more widely applied to secure greater strength and more uniform 

 seasoning and thus to reduce to some extent the one drawback to wood 

 as a material of construction, that is, its liabilility to "working" 

 (shrinking and swelling). The reason for the superiority of quarter- 

 sawed pieces, as well as the general fact that the manner of sawing 



