60 



If any beam under a floor, intended to 

 support great weight, has large knots in 

 it, it very probably will break, some time 

 or other, at one of them. We frequent- 

 ly see beams of large scantlings, put in- 

 to such places, in order to give strength ; 

 which, upon examination, may be found 

 not half so strong, as if tolerabh^ free 

 from them. A large knot near the cen- 

 tre, is an extremely dangerous circum- 

 stance ; as there the pressure will of course 

 be greatest. Often, however, we find two, 

 three, and even four such knots, in foreign 

 Fir timber, and these placed opposite to 

 each other ; every one of which increases 

 the danger of breaking*. 



* Where the beam is so lame as to take the whole 

 thickness of a fir loar, whose branches have "jrosvn in 

 annual sets, or opposite to each other, as is the case 

 with foreign red deal, all such logs produced from the 

 higher parts of the tree, are extremely liable to this 

 sort of defect. To put such in places where much 

 strength is required, is one of the worst species of 

 deception. 



