BOA] ( 14 ) 



Blockhead. A dullard; a stupid person; one without brains. 

 Originally a wig-maker's wooden dummy, upon which he 

 worked and exhibited his wigs. 



" Strongly wedged up in a block-head." 



Shakespeare, Coriolanus, ii. 3. 



Block-house. A place of defence made of logs. 



" Blue Goods," or Blue Timbers. Sawn goods which have become 

 discoloured on the sapwood through stains by fungi. These 

 are laid aside and occasionally shipped as blue goods, 

 without warranty. 



Blue Gum (E. Saligna). A heavy, strong Australian timber. 



Bluing. Discoloration of the sapwood by low forms of vegeta- 

 tion acting as ferments. 



Board or Boards. (1) Thin layers of wood, from i in. to 2 in. in 

 thickness, when " plank " comes in. In the hardwood 

 trade boards are classed as of any thickness up to 1J 

 in. and any width ; over that thickness they are termed 

 planks. In the softwood trade it is customary to include 

 as boards any thickness under 2 in. (2) A table, from 

 having a flat or broad surface made of boards. This word 

 and broad seems to be allied in origin, as "onboard a ship" 

 suggests going over the broadside. See " Table." 



Board of Trade Unit. Generally represented by the initials 

 " B.T.U." Is the unit by which the amotmt of electric 

 current used is measured. It is equal to 1,000 watts for 

 one hour. One B.T.U. is equal to 1 '34 h.p. for one hour. 



Board Foot. The contents of a board 1 ft. square and 1 in. 

 thick. The common unit of measure for logs and lumber 

 in the United States and Canada. See " Board Measure." 



Board Measure. The board foot, the unit of measxirement in the 

 United States and Canada, is an invariable standard 12 in. 

 square and 1 in. thick, or its equivalent of volume in any 

 other shape. One thousand feet board measure of -in. 

 lumber is, therefore, equivalent to 2,000 ft. face of super- 

 ficial measure. Lumber 1 in. or thicker is usually sold by 

 board measure, and lumber under 1 in. is by the custom of the 

 trade usually sold by face measure, not by board measure. 

 When applied to inch lumber, this unit may be considered a 

 measurement of surface, but with lumber of other dimensions 

 it is a unit of volume containing 1 44 cubic in. A few examples 

 will explain this more clearly. A board 12 ft. in length, 1 ft. 

 in width and 1 in. in thickness contains 12 board ft. and its 

 surface measurement is 12 sq. ft. A board 12 ft. long, 

 12 in. wide and 2 in. thick contains 24 board ft., while its 



