n8 



ENGINEERING ON THE FARM 



Shiplap. Lumber which has been prepared with a joint 

 as in Figure 121. 

 SiS. Lumber surfaced on one side. 



S1S1E. Lumber surfaced one 

 side and one edge. 



S2S1E. Lumber surfaced on two 

 sides and one edge. 



S4S. Lumber surfaced on four 

 sides. 



iS. One side. 



Veneer. A thin sheet of an orna- 

 mental or long-wearing wood glued 

 on the surface of a cheap wood. 

 The veneer gives a finish and wear- 

 ing surface and the other rigidity 

 and strength. 



Wane. A term applied to indicate 

 a shortage of wood or the presence 

 of bark on one edge of a timber. 



Fig. 120. 

 Lapsiding 



Fig. 121. 

 Shiplap 



Classification. All lumber 



to 1 



in thickness is 



known as board. Sizes from 2 V X4" to 4"X6" are known as 

 dimension or light timber. Heavier than 4" X 6" is usually 

 known as timber. 



Grades. Lumber is graded according to the species of 

 the tree from which it is produced, the term usually indicat- 

 ing its quality, as hard or soft. It is also graded according 

 to the purpose for which it is to be used, as flooring, siding, 

 or fencing; dimensions to which cut, as boards, 1 inch by 

 8 inches by 12 feet, or 2 inches by 4 inches by 14 feet; and 

 defects with respect to their bearing on the structure in 

 which it is to be used, as C flooring, A clear siding, or No. 3 

 fencing. Each of these terms indicates a certain freedom 

 from knots and other defects in the lumber named. 



The system of grading is not uniform over the country, 

 and its nomenclature is not completely standardized. The 

 same name is not always given to the same species of tree, 



