156 



CEMENT AND CONCRETE 



crushed stone to complete the job, using a 1 : 2 : 4 mix- 

 ture, a sufficient quantity of boards, and 2 x 4's to 

 make and brace the 

 form, and pieces of 

 wire with which to 

 fasten it together. 



Preliminary Instructions: 

 Concrete is the best 

 material available 

 for foundation wall 

 construction. The 



FIG. 151. Foundation wall form. 



super - structure 

 may be built of some 



other material, but usually concrete will be used for 

 the foundation. The particular location of hot-bed 

 or foundation wall should be definitely decided so the 

 work will not be held back at the beginning of work 



period. To lay out a 

 rectangular foundation, 

 one should be careful to 

 have all intersections of 

 walls exactly 90 degrees. 

 This can be easily 

 checked by the "3, 4, 5" 

 FIG. 152. Wall form above ground. method. This rule is 

 applied by measuring along one wall a distance 

 from the corner equal to 3 feet; then measure from the 

 same point along the other wall a distance of 4 feet; 

 then, if the two lines form an exact right angle, the dis- 

 tance between the ends of the 3- and 4-foot lines will 



