VERTICAL AND INCLINED SURFACES OF SEPARATION 



283 



A curve constructed for the ratio — '- = , coincides with the calcu- 



{Qi.k)L 99' 

 lated curve in its initial and final parts. In the central portions the minimum 

 of the constructed curve rises higher 



{Q2, kJL Q2 



We were unable to construct a curve for the ratio 



foi 



{Qi, k)L {Qi, kJL 

 sufficiently large spacings of AB, owing to the absence of curves with mod- 



Q2 



< 0.01 on the CV-25 reference graph. 



ulus 



(Qi, k)L 

 In the part for which the construction was made, the least divergence 



from HVC curve was observed for - — = 2, while for — = — complete coin- 



cidence with the HVC curve was observed. If the distance of the separations 



of AB is increased the approximately constructed curve for the condition 



(^2, k)L Q2 



deviates considerably, as would be expected, from the 



(Qi, 



k)L 



(Qh k)l 



AB 



HVC curve, since (^2 k)L ~^ °°' ^°^ ~^ °°- 



When the spacings of AB are orientated perpendicular to the plane of 

 the contact the approximately constructed curve is observed to coincide 

 completely with the calculated curves owing to the fact that the influence 

 of the vertical contact diminishes as the spacings of AB increase. 





V V V V \r^ 



/>=00 



-(a) (b) ■o-'^(c) 



® Values of^ 

 \oo] Values of ^ 



Fig. 9. a — VEP curves for a horizontally homogeneous medium; b — approximately 

 constructed VEP curves; c — curves of the CV-3S reference graph. 



