UNIVERSAL DIP CHART 
value of K, parallel to the ordinate, to this curve. Project this 
point of intersection parallel to the abscissa to tangent table. 
The tangent curve is given on left page for convenience in con- 
verting this tangent to degrees dip. 
2. Same procedure as (1), using down dip group of curves. 
3. a) Assume an approximate value of V2 as the arithmetical average 
of velocities up and down dip. 
b) Determine tentative values of K (up dip and down dip) from 


We 
the relation K = 
V2 
Vi 
c) Determine tentative value of B from B = cot sin” 
V2 
From tentative values of B*and K above, read from curves the 
values of tan « for both up dip and down dip cases. Assume average 
value of these tangents and read curves back to new values of K for 
average of tan «. Two values of V. can now be determined from 
the values of K (K = 

) and the apparent velocities. These two values 
9 
of V2 may be averaged, a new value of B determined, and the process 
repeated until the values of V: agree. In most cases, the second trial 
will give values closely identical. 
An explicit solution of V2 in terms of V2:, V2, and « will be found 
in equation 19, Page 639, “Geophysical Prospecting—1929.” 
An explicit solution of V: in terms of Vi, V+, and V2 as reduced 
from equation A, is given here: 
Vee VV Van VV 
Ee ee ee eV 
V2. +V2- 

Ve = 
