249 



TABLE XIX. 

 NUMBER OF ROOFING SLATES REQUIRED TO LAY ONE SQUARE OF ROOF WITH 



3-INCH LAP. 



TABLE XX. 

 THE WEIGHT OF SLATE REQUIRED FOR ONE SQUARE OF ROOF. 



Length 



Weight in pounds, per square, for the thickness. 



TABLE XXL 

 WEIGHT OF SLATE PER SQUARE FOOT. 



