CON] (28) 



Comb-grain, quarter sawed, edge grain, rift sawn, vertical grain, 

 are all synonymous terms and refer to wood sawn parallel, 

 or approximately so, to the medullary rays. Practically, 

 however, the angle of the annual rings should not exceed 

 45 degrees from vertical. This method of cutting pitch 

 pine is especially desirable for flooring, inasmuch as edge 

 grain is more durable under the wear to which flooring is 

 subjected. 



Common Pitch. A term applied when the length of the rafters 

 is equal. 



Common Rafter (otherwise "roof-spar"). The upper part and 

 sometimes the only timbering of a roof ; the light or scantling 

 part, placed at intervals as supports for the laths, tiles, 

 slates, etc., which form the covering. See " Roof Timbers." 



Compass Roof. One in. which the tie from the foot of one rafter 

 is attached to the opposite rafter at a considerable height 

 above its foot. " Compass window " is a term for a window 

 circular in plan. 



Compo Boards. Boards of wood fibre and other substances, used 

 in the interior of houses in place of lath and plaster. See 

 " Beaver Boards " and " S.X. " Boards. 



Compression. (1) One of the technical tests applied to wood 

 to arrive at its power of resisting thrust or pressure longi- 

 tudinally ; (2) a wood column whose office it is to support 

 beams and floors overhead, as corn chambers, illustrate 

 wood as a substance in compression. The like may be said of 

 the strut, head or upper beam of a queen-post roof, or a 

 block of wood carrying a smith's anvil : compression is 

 the opposite of " tension " (which see). Struts, wherever 

 they occur, as in gates, are considered to be in compression, 

 but exceptions occur in practice. 



Concave Saw. A circular saw, concave in form. 



Concentric Rings. Woody layers which define the yearly growth 

 of a tree. 



Conifers. Trees of the order of Conifcree or cone-bearing trees. 

 See " Conifers." 



Coniferse (Lat. cone-bearers). An important natural order of 

 exogenous trees, embracing pines, firs, juniper, cypress, 

 yews, etc., the fruit of which is a cone. Many kinds of 

 coniferse are productive of turpentine and resins. As the 

 name suggests, they are cone-bearing trees. 



Coniferous. Belonging to the order of Coniferee. 



Conk. An American term for the decay in the wood of trees 

 caused by fungus. 





