FOUNDATIONS AND FOOTINGS 



21 



of the foundation trenches with a heavy rammer, before commencing 

 to build the footings. If any grave doubt exists as to the solidity 

 of underlying strata, these may be examined by sinking trial pits. 



Setting out the Foundation Trenches. — It is most important that the 

 foundation trenches and footings should be set out correctly, so as to give 

 the building accurately squared corners from the beginning. 



Cheap farmers' levels are now procurable which are provided with 

 a graduated circle, by the use of which angles can be set out. Such 

 an instrument will be found 

 useful for the purpose under 

 discussion. 



Should no instrument of 

 this nature be available, a 



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Fig. 10. 



Fig. 11. 



right-angled triangle can be constructed out of three flooring boards as 

 shown in Fig. 10. The flooring boards are nailed together so as to form 

 a triangle, with sides respectively 6, 8, and 10 feet long; the angle con- 

 tained between the two shorter sides is a right angle. 



The triangle is used as indicated in Fig. 11, stretched lines or cords, 

 attached to pegs driven into the ground, being employed to mark out the 

 trenches. It will be observed from Fig. 11 that the pegs are driven well 

 outside of the trenches. If they be placed too near the trenches they 

 are liable to be disturbed during the process of excavation. 



Footings. — The term " footing " has been tacitly used, in the preceding 



