ANGULAR SURVEYING 



61 



The following example shows the required calculation for 

 determining the area of a closed field similar to the one shown 

 in Fig. 4. 



E' 



FIG. 5 



Balancing the Survey of a Closed Field. When a platted 

 survey of a closed field does not close, as in Fig. 5, that is, 

 when the point Ai, which is the end of the last line, does not 

 coincide with the point A , which is the beginning of the first 

 line, the line AiA is called the error of closure and the 



