ABC OF THE STEEL SQUARE 99 



pitch of roof. Fig. 64 shows the square set to 

 the pitch of the hip rafter. The squares as set 

 give the plumb and level cuts. Fig. 65 is the 

 rafter plan of a house 18 by 24 feet; the rafters 

 are laid off on the level, and measure nine feet 

 from center of ridge to outside of wall ; there 

 should be a rafter pattern with a plumb cut at 

 one end, and the foot cut at the other, got out as 

 previously shown. When the rafter foot is 

 marked, place the end of the long blade of the 

 square to the wall line, as in drawing, and mark 

 across the rafter at the outside of the short 

 blade, and these marks on the rafter pitch will 

 correspond with two feet on the level plan: 

 slide the square up the rafter and place the end 

 of the long blade to the mark last made, and 

 mark outside the short blade as before, repeat 

 the application until nine feet are measured off. 

 and then the length of the rafter is correct ; 

 remember to mark off one-half the thickness of 

 ridge-piece. The rafters are laid off on part of 

 plan to show the appearance of the rafters in a 

 roof of this kind, but for working purposes the 

 rafters 1, 2, 3, 4, 5 and 6, with one hip rafter, 

 is all that is required. 



To proceed, we first lay off common rafter, 

 which has been previously explained; but deem- 

 ing it necessary to give a formula in figures to 



