72 JOURNAL OF FORESTRY 



Basal area. The area of a cross section of a tree, usually expressed in square feet, 

 and usually referring to the section at breast-height. The sum of the basal areas 

 of trees in a stand is the basal area of the stand, and is usually expressed in square 

 feet per acre. 



G., Stammgrundfiache. F., surface terriere. 



Base capital. See Capital. 



Biltmore stick. A graduated rule, usually of wood, the graduations of which indi- 

 cate (when the rule is held tangentially to the tree) the diameter of the tree at the 

 point where measured. The rule is constructed on the principle of similar triangles. 

 See also CaHper. 



Blank. An opening in the forest where, from any cause, very few or no trees are 

 growing. 



G., Blosse. F., vide. 



Blaze, V. The process of marking a tree by means of a sharp instrument, removing 

 part of the bark. 



Blaze, n. A spot made on a tree by chipping off a piece of bark. 



Block. See Under subdivision. 



Blow-down. See Windfall. 



Board foot. A unit of measurement represented by a board one foot long, one foot 

 wide and one inch in thickness, or its equivalent in volume. In finished or sur- 

 faced lumber the board foot measure is based on the measurement before surfacing 

 or other finishing, or on the superficial measure only. 



Board measure. A term expressing the^board foot content of round or manufactured 

 timber; and for expressing the volume of logs, trees or stands in terms of the esti- 

 mated amount of lumber which may be cut therefrom according to various log 

 rules {q. v.). Usually abbreviated B.M.; units of larger quantities stated in 

 thousands, are abbreviated M B.M. 



Board rule. 1. A tabular statement showing the board foot contents for various 

 widths and lengths of squared timber, or of sawed timber. 



2. A graduated stick for determining the contents of squared timber. The 

 number of board feet in squared timber of given widths and lengths, or of sawed 

 timber, is shown upon the rule. See Scale stick. 

 Syn.: lumber rule, lumber scale. 



Board scale. See Board measure. 



Bole. See Stem. 



Border cutting. See Reproduction, Strip-selection method. 



Breast-height. A height of 4}^ feet above the average ground surface or above 

 the root collar, the diameters of standing trees being ordinarily measured at this 

 height (abbreviation d. b. h.). 



G., Brusthohe. F., hauteur d'homme. 



Breast-height form factor. See Form factor. 



Broadcast seeding method. See Direct seeding. 



Broken. See Crown density. 



Brushwood stage. See Development class. 



Budget regulation. See Regulation of cut. 



Bunch planting. See Forest planting. 



Bum, n. An area over which fire has run to the noticeable injury of the 

 forest. 



