A B C OF THE STEEL SQUARE 



121 



inches; deduct the height of the first tan- 

 gent from lOl/o inches; take the difference on 

 the tongue and width from C to D on the blade ; 

 the tongue gives the cut for the second tangent. 

 Mark the pitch of the first tangent on the edge 

 of the second and cut to this ; the pitch of the 

 second tangent gives the edge cut of the first. 

 Cut and fix together with stretcher as previous- 

 ly described. 



Fig. 84. 



To get out the face mold, procure a piece of 

 thin stuff. Three-ply wood is excellent, as though 

 it is liable to warp it does not shrink perceptibly. 

 Shoot on edge and gauge on a center line ; take 

 the distance from B to D (Fig. 84) (the hy- 

 po thenuse of 6 and 6) on the blade and the rise 

 (10%) at D on the tongue; lay on the edge 



