161] 



CONFORMAL REPRESENTATION. 



323 



minima eventually become negative. The curves all cut the axis 

 of u' to the right of the origin, but stretch out farther and farther 



27T 



FIG. G7. U' F'-plane. 



toward the left, so that for # = the curve reaches from to 

 minus infinity, coinciding with the left-hand half of the u' axis. 



212 



