GEOLOGICAL SECTIONS. 43 



number of degrees of dip observed along the other line, 

 and connect the two points by a line a b. 



Fig. 11. 



(This line coincides with the strike, and is conse- 

 quently at right angles to the true dip's direction.) 



EULE B. When one observed dip inclines from, and 



Fig. 12. 



the other towards the angle enclosed by their lines, 

 fig. 12, the true dip follows a line (c d) laid down by the 

 following method : 



Set off from the angle on each of the two lines of 

 apparent dip a number of units corresponding to the 

 number of degrees of dip observed along that line, and 

 connect the two points by a line c d. 



(This line coincides with the true dip's direction.) 



