28 



ABC OF THE STEEL SQUARE 



The octagon scale on this square runs along 

 the middle of the face of the tongue, and is used 

 for laying off lines to cut an "eight square" or 

 octagon stick of timber from a square one. 



A J 



Fig. 11. 



36 in. 



Fig. 12. 



Suppose the figure ABCD (see Fig. 2) is the 

 butt of a square stick of timber 6x6 inches. 



