152 A MANUAL FOR NORTHERN WOODSMEN 



tence of sawyers is one cause of this, and that, according to 

 careful mill men, may readily amount to 10 per cent. Then 

 market demand affects the matter, some mills being so 

 situated that they can market only the larger sizes of lumber. 

 The type of saw employed and the methods of handling 

 on the carriage also have their effect. 



TABLE I 



Yield in inch boards, squared, of second growth white pine 

 logs. Based on 740 logs; study by Harvard Forest School. 



Growth extra tall and smooth; large and small trees in 

 the stand, which was cut clean; logs with 2 in. crook or 

 over thrown out. Sawed by circular saw cutting }-inch 

 kerf. In scaling, fractions of inches up to .5 were thrown 

 off, fractions of .6 and over taken as if of inch above. 

 Boards merchantable down to 2 feet, surface measure; 

 some wane allowed. 



A practice that in some localities of recent years has 

 greatly increased tjje merchantable product of logs is that 

 of sawing waney or round-edged boards. Portable mills in 

 southern New England sawing lumber for boxes or finish 

 follow this practice largely, and stationary mills in many 

 localities have a box or other saw to which they can turn 

 over the small and crooked logs for this most economical 



