Figure 25-2. Wulff meridional stereographic net drawn to 2° intervals. 



the plane can be represented equally well by its normal, which passes through 

 the center of the sphere. In Figure 25-1 the intersection P of the normal with the 

 surface of the sphere is projected to the zenith. Where this line penetrates the 

 equatorial plane, the point P' locates the normal on the stereographic net. If 

 the plane has a dip of 40 degrees, the normal will have a hade of 40 degrees. On 

 the stereographic net, the dip of the plane will be measured inward from the 

 circumference, whereas the hade of the normal will be measured from the center 

 outward. 



Polar Stereographic Net 



Various types of stereographic nets have been developed for special pur- 

 poses, but the Wulff net (fig. 25-2) is most generally used. If planes are passed 



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